Brown Hot Water

brettmirl

Been having a problem for the last few weeks with the hot water in my house. It's coming out of the taps brown in colour.

I've drained the tank in the hot press a few times till it runs clear, but the colour keeps coming back. It's the same out of all the taps. The cold water is crystal clear.

I've checked the tank in the attic and that is clear too.

Would it be a case that the heating element in the cylinder in my hot press is rusting/decaying and colouring the hot water? The house is about 10 years old or so, so I'm guessing the cylinder is about the same.

The brown colour seems to be worse after the water has been heated by the gas central heating and not so bad if I use the immersion.

Anyone have a solution or is the best thing to just replace the cylinder?

ART6

It sounds to me like the hot water coil in your cylinder is leaking since the brown colour would be normal in the central heating circuit. If you have a pressurised central heating system then the system pressure should have dropped to zero and need contant refilling, unless the make up valve has been left open. If it's an atmospheric system then the header tank would have to be higher than the cold water tanks to get the central heating circuit water to flow into the cylinder contents.

In either case I would bet that it is the coil since the fact that it seems worse when the central heating is on really confirms it, as that is when the circulating pump is running. Either way, you need to get it fixed as otherwise the water circulating in the radiators will be continuously oxygenated, and that will cause the rads to rust from the inside out.

The only way to find out is if you have two valves on the coil at the cylinder (both on the side, one a third of the way down from the top and one a third of the way up from the bottom) then shut off the central heating system, shut off all radiators (both valves), drain the system and shut off the upper valve, then disconnect a pipe from the lower valve and open it while leaving the cold water tank filled. If clear water runs out then the coil has failed. Careful though -- you might get a lot of water if you don't close the valves quickly enough!

brettmirl

Thanks Art6...I know shag all about plumbing, so will be getting someone in to sort it I'd say.

Silly question time: Can you replace the coil, or would the whole cylinder have to be replaced?

This is what my tank looks like - http://i35.tinypic.com/2804ep0.jpg That't not my actual tank but the closest to what it looks like on Google!

ART6

brettmirl wrote: »

Thanks Art6...I know shag all about plumbing, so will be getting someone in to sort it I'd say.

Silly question time: Can you replace the coil, or would the whole cylinder have to be replaced?

This is what my tank looks like - http://i35.tinypic.com/2804ep0.jpg That't not my actual tank but the closest to what it looks like on Google!

No, you can't simply replace the coil as it is fitted before the top is fitted into the cylinder. If you're going to hire a plumber then be sure to ask him to test the coil or he might simply take you at your word that it's banjaxed and charge you to replace the whole thing. Testing it is easy enough if you do it the way I suggested, but if you don't feel confident about that (and it can be a messy job) then best leave it to a professional;)

Have to say I'm a little surprised that it has failed in such a short time -- It's possuble I guess, but I have not persoannly come across such a thing.

brettmirl

I noticed the water turning brown after the mains water was disrupted to the whole area about two months ago.

I thought it might just have been dirty mains coming through the system once the water was restored, but it didnt clear up at all.

Getting a plumber in tomorrow to take a look at it. Thanks for the advice!

ART6

No bother. Hope it works out for you!

brettmirl

Ok so got a plumber out on Friday. He checked and said it was the coil. Got the cylinder replaced...all was grand, water clear again, till today!

Back to being brown again :mad:

The tank in the attic is clear, cylinder is now replaced. The water from the cold taps is crystal clear...it just the hot taps that are affected.

Anyone have any idea what the hell might be causing it?

ART6

The water to the hot taps comes from the cylinder, while the cold taps are suplied direct from the tank, so there is no connection between them except that the tank also supplies the cylinder. If the coil had failed then the brown colour would be caused by the sludge in the heating circuit. That's basically rust from inside the radiators but once it's used up all the oxygen in the circuit it becomes stable. It does, however, stick to pipes etc very well indeed, so maybe the problem is that the hot water circuit needs to be well flushed or some sediment in the pipes may become dislodged. Only way to find that out, I suspect, is to turn off the immerser and the heating supply to the cylinder and then run all of the hot taps full bore for a while and see if it clears.

Not all plumbers are that careful, and if he didn't flush the hot water system it may be that it has now delivered a dose of brown to the cylinder, so flushing for an hour or so might clear it.

The only other possibility I can think of, other than the very unlikely event that the coil in the new cylinder is also faulty, is that the vent pipes from the hot water system and the central heating system have been connected, but that would only work with an atmospheric central heating system and it would always have produced brown hot water.

If the flushing doesn't work, I'd suggest calling the plumber back and telling him the problem isn't solved. A good tradesman wouldn't want to leave a dissatisfied cutomer behind;)

Darth Maul

brettmirl wrote: »

Ok so got a plumber out on Friday. He checked and said it was the coil. Got the cylinder replaced...all was grand, water clear again, till today!

Back to being brown again :mad:

The tank in the attic is clear, cylinder is now replaced. The water from the cold taps is crystal clear...it just the hot taps that are affected.

Anyone have any idea what the hell might be causing it?

are you supplied by mains or a well, could be iron in the water that turns brown when heated. or could also be iron bacteria, if so the tank and cylinder will need to be dissinfected.

brettmirl

Cheers again ART6. I turned off the heating supply to the cylinder and ran the water for about 40mins or so. Was running clear at that stage. Will see how I go over the next few days.

Darth - Am supplied from a Meath CoCo mains supply.

brettmirl

OK, so after running the hot water for 40mins last night till it run clear, the water is now starting to turn brown again.

Would it be worth flushing the system a few times? Should I shut off the heating going to the water for a few days and keep flushing it?

yoshytoshy

Try and find out if your heating feed pipe is taken from your cylinder feed pipe.
Sometimes you can get heating water ,getting into the supply pipe of the cylinder.

I haven't read the other replies ,my eyes are too heavy.:(
Goodnight.

brettmirl

I've no idea to be honest yoshytoshy. I know shag all about plumbing

I've just taken some photos of my cylinder...hopefully it might help with a diagnosis!

ART6

The pipework is a bit confusing, for me at least, but one thing I notice is that the system make-up valve (the one with the black lever on the top end of the braided metal pipe) looks to be fully open in one photo and partly open in another. That is normally for repressurising the system in the event of loss of pressure, and it should have a non return valve by it to prevent water flowing back from the heating circuit into the cold water supply. I can't see a non return valve, but in any case the black lever valve should normally be closed. I suppose there's a vague possibility of water flowing back from the heating circuit through it, in which case brown water will result if the system pressure ever gets higher than the mains pressure.

If the hot water went brown again after long flushing then I would guess that heating circuit water has to be still getting in somewhere.

yoshytoshy

You should get the plumber back who installed the cylinder ,he's sure to want to fix it for you.

This problem could mean you have issues with your heating system aswell. Fixable with about an hours work.

JamesM

It's all very confusing. It doesn't look as if there is a mains supply anywhere. The fitting below the red valve on the left could be a non return valve, so that pipe may be from the tank in the attic. The pipes on the right seem to be water to the household taps etc. And the left look like they are the heating system. But the way some of them disappear around the back of the cylinder looks as if they may be linked with the pipes on the other side of the cylinder. We would need to know where all the pipes are coming from and going to, to work out what's what. Also, the braided pipe seems to be some kind of bypass.
Jim.

brettmirl

ART6 wrote: »

The pipework is a bit confusing, for me at least, but one thing I notice is that the system make-up valve (the one with the black lever on the top end of the braided metal pipe) looks to be fully open in one photo and partly open in another. That is normally for repressurising the system in the event of loss of pressure, and it should have a non return valve by it to prevent water flowing back from the heating circuit into the cold water supply. I can't see a non return valve, but in any case the black lever valve should normally be closed. I suppose there's a vague possibility of water flowing back from the heating circuit through it, in which case brown water will result if the system pressure ever gets higher than the mains pressure.

If the hot water went brown again after long flushing then I would guess that heating circuit water has to be still getting in somewhere.

Thanks Art6 - should that black tap on the braided pipe be pointing up, or out towards me? It's halfway between both positions at the moment.

yoshytoshy wrote: »

You should get the plumber back who installed the cylinder ,he's sure to want to fix it for you.

This problem could mean you have issues with your heating system aswell. Fixable with about an hours work.

The heating system is reasonably new. Got some new rads and a new gas boiler in at the start of the summer...using the same plumber. Just left a message for him to give me a buzz back.

JamesM wrote: »

It's all very confusing. It doesn't look as if there is a mains supply anywhere. The fitting below the red valve on the left could be a non return valve, so that pipe may be from the tank in the attic. The pipes on the right seem to be water to the household taps etc. And the left look like they are the heating system. But the way some of them disappear around the back of the cylinder looks as if they may be linked with the pipes on the other side of the cylinder. We would need to know where all the pipes are coming from and going to, to work out what's what. Also, the braided pipe seems to be some kind of bypass.
Jim.

I've no idea what pipe is for what or where they are going.
Will take some pics of the back of the tank this evening.

ART6

brettmirl wrote: »

Thanks Art6 - should that black tap on the braided pipe be pointing up, or out towards me? It's halfway between both positions at the moment.

Like jamesm said, the braided pipe does look almost as if it's some form of bypass. However, in pressurised heating systems the braided pipe is normally for restoring system pressure from the cold water supply. It is flexible because it is usual for it to be left disconnected and for it to be coupled to the mains only when topping up is necssary. However, many installers I have come across connect the pipe permanently to the cold water supply, in which case the connection should have a non return valve in it as well as a shut off valve to prevent heating system water flowing backwards into the cold circuit. If there is such a valve it could simply be stuck open.

The fact that the valve on the end of that pipe has a black lever when all the other valves have red ones suggests to me that it's a make up supply, although I can't follow the pipe layout either. If it is then the lever should be at right angles to the pipe to close off, and in line with the pipe to be open.

All I am saying is that if replacing the cylinder and its faulty coil, followed by lengthy flushing, provided clear water for a while but returned to brown discouloration when the heating was turned on, then the water from the heating circuit is getting into the hot water circuit somewhere when the heating system pressure rises. Assuming that the new cylinder is OK and that this is something that has not always happened in the past, then that braided pipe and it's valve seems like a possible culprit to me, but that is only a guess!

brettmirl

Another update!

I was talking to the plumber who installed the new cylinder and he is "baffled" as to what the problem could be.

At the moment, I've turned off the red valve at the end of the cylinder and turned the TCV off, so the cylinder is not getting any heat from the gas central heating. I'm using the electric immersion to heat the water at present.

So far, the water is clearer than if its heated by the gas...but am going to give it till this evening to see if that changes or not.
There is still a colour difference between the water coming from the hot and cold taps, but it's nowhere near as bad. Plus you would only really notice it if you were looking for it.

I've attached a few more photos of the pipework, which hopefully will make the layout a little bit clearer. On the last pic attached, P1010539, the red lever to the left of the TCV - that is for shutting off the heat to the radiators and heating the hot water only.



Once again, thanks to everyone for their help and advice. I really appreciate it.

ART6

OK, going by your latest photos and using the one attached below, I suspect the pipework arrangement is:

1. Is the filling valve for the heating circuit
2. Is the pressure relief pipe for the boiler flow line, hence the relief valve on the end and the filling connection to the braided pipe. Opening the black levered valve would supply make up water from the attic tank to the heating circuit.
3. Is the hot flow pipe from the boiler
4. Is the cold water supply from the attic tank.
5. Is a cold water supply from the tank to some taps somewhere.
6. Is the cold water supply to the hot water cylinder.

If that's correct then the black levered valve (1) should be closed except when the system needs to be repressurised. In the photo it looks partly open, and there doesn't seem to be any non-return valve associated with it. So, if the boiler is up to full pressure it might overcome the pressure head from the attic tank and force heating circuit water into the cold supply to the cylinder.

Again, best guess:p


P1010539.JPG

JamesM

Two pionts Art, There is a non return valve behind your no. 1 arrow, below the red handled valve.
Which is the return coil connection.
I can't figure it out at all
Jim

ART6

JamesM wrote: »

Two pionts Art, There is a non return valve behind your no. 1 arrow, below the red handled valve.
Which is the return coil connection.
I can't figure it out at all
Jim

Yes, I saw that too. All I can think is that is in the cold supply from the attic tank since the NR valve indicator is pointing downwards and the braided pipe comes off that supply lower down. Why the tank supply would need an NR valve confuses me too since the cylinder cannot reach any pressure greater than the tank head. I suspect that the coil return connection is in the top of the cylinder since there is a pipe there off centre -- in any case it's not the hot water supply to the taps as that is in the top centre.

Anyway, the only source of brown water in the hot water circuit that I can imagine is a back flow through the braided filling pipe since the OP seems to suggest that the situation occurs when the heating is on. If that's the case then I would expect the black valve (1) to be closed unless the system needs repressurising, in which case back flow would not be possible until full system pressure was restored. Do you think that might be the case?

JamesM

Looking at this photo https://us.v-cdn.net/6034073/uploads/attachments/19940/99106.JPG , I think that 3 and 4 are meant to be the flow and return. Also looking at the cylinder, 4 goes down to 6, which looks like the right position on the cylinder for the return to the boiler. Don't ask me where that leaves anything else . Also if 4 is the return, there probably should not be push fittings.
A plumber needs to go in there and see where every one of those pipes goes to and from.
Jim.

Just looked at earlier post - he turned off the red valve at the bottom of the cylinder, so that can't be the cold feed, or he wouldn't have had any water in the hot taps.

brettmirl

Thanks again ART6. Going to try shut off that black tap and see what happens.

When the heating is on and I turn that fully on, I can hear what sounds like water flowing through the pipes.

The plumber has told me to turn off the red tap you can see in this pic:

https://us.v-cdn.net/6034073/uploads/attachments/19940/99107.JPG

The red tap on the left of the photo, beside the relief valve, and see how it goes.
He also got me to fill the kettle with some cold water from the bathroom tap and boil it to see if boiling/heating the water made any difference. It didn't.

ART6

JamesM wrote: »

Looking at this photo I think that 3 and 4 are meant to be the flow and return. Also looking at the cylinder, 4 goes down to 6, which looks like the right position on the cylinder for the return to the boiler. Don't ask me where that leaves anything else Also if 4 is the return, there probably should not be push fittings.
A plumber needs to go in there and see where every one of those pipes goes to and from.
Jim.

Just looked at earlier post - he turned off the red valve at the bottom of the cylinder, so that can't be the cold feed, or he wouldn't have had any water in the hot taps.

Yes, you could be right there, and I withdraw my previous post:p Trouble is, if that is the case, and given that pipe #2 connects (among other things) to the thermostatic valve, then all the braided hose does is connect the flow and return and bypass the coil, which is why the OP would hear water flowing through it with its valve open. However, on the systems I have had any dealings with the braided hose has always been the heating circuit filling valve, not a bypass. If in this case it is not, then where does the system make up come from? If you are right, and 4 is the return to the boiler, then that would make the NR valve on the spur above it the make-up from the roof tank. In that case we are back to the question of where the brown water is coming from because my original theory has gone down in flames. Much more of this and I think I'll take up knitting instead:D

I agree with your note about the red valve. If 3 and 4 are the flow and return then shutting that would simply isolate one side of the coil.

brettmirl wrote: »

Thanks again ART6. Going to try shut off that black tap and see what happens.

When the heating is on and I turn that fully on, I can hear what sounds like water flowing through the pipes.

The plumber has told me to turn off the red tap you can see in this pic:

The red tap on the left of the photo, beside the relief valve, and see how it goes.
He also got me to fill the kettle with some cold water from the bathroom tap and boil it to see if boiling/heating the water made any difference. It didn't.

OP I'm sorry that this issue is slowly descending into a technical discussion between jamesm and me. That's what you get for posting intriguing questions like this:D Jim has demonstrated many times in this forum that he knows his stuff, and if he is confused then I have every right to be. Hang in there -- we may yet work it out!

brettmirl

Thanks to you both...If it's baffled the two of you, god knows what hope there is of a solution!

brettmirl

Oh actually ART6, meant to ask earlier, does that mean I should leave the black valve slightly open as it is?

Or is it ok to close it and see if it makes a difference?

ART6

brettmirl wrote: »

Oh actually ART6, meant to ask earlier, does that mean I should leave the black valve slightly open as it is?

Or is it ok to close it and see if it makes a difference?

If it's a make-up valve then it should be normally closed. If, as jamesm suggests, it might be a bypass valve, then closing it will simply allow the full boiler flow through the coil. All that will do is possibly starve your radiators, but it looks too small a bore for that from what I can see.

Jamesm -- If the bottom red valve is the heating circuit return, then where is the cold water feed to the cylinder and why is there a vertical 15 mm pipe coming off it and up through the ceiling with an NR valve arrow downwards? Also, why is there a plastic pipe coming off it and disappearing behind the cylinder? The pipe the the thermostatic valve is in copper by the looks of it, as I would have expected the boiler circuit pipes to all be.

OP, one way to check which pipes are which would be to let the cylinder go cold, then turn on the central heating and see which pipes immediately warm up and which stay stone cold for some time.

brettmirl

ART6 wrote: »

OP, one way to check which pipes are which would be to let the cylinder go cold, then turn on the central heating and see which pipes immediately warm up and which stay stone cold for some time.

Will check that when I get home this evening and let you know.

Going from your pic - https://us.v-cdn.net/6034073/uploads/attachments/147547/99128.JPG - The pipes marked 3 and 6 get hot straight away when the boiler is on, but will check all of them this evening to be sure.

With the black valve turned to closed and the red knob also off, there's been no change in the colour of the water. Usually by now, it would have gotten more brown.

ART6

brettmirl wrote: »

Will check that when I get home this evening and let you know.

Going from your pic - https://us.v-cdn.net/6034073/uploads/attachments/147547/99128.JPG - The pipes marked 3 and 6 get hot straight away when the boiler is on, but will check all of them this evening to be sure.

With the black valve turned to closed and the red knob also off, there's been no change in the colour of the water. Usually by now, it would have gotten more brown.

OK so. If those pipes heat immediately then jamesm is correct. They are the boiler flow and return and the braided pipe is the coil bypass. In that case the pipe with the NR valve close to the braided hose must be the system make up from the attic tank, hence the NR valve. So another thing to test -- Immediately above the NR valve is a red handled screw valve. If you shut that then there will be no make up water getting to the boiler circuit (it shouldn't need to be open all the time anyway). If, with that valve closed and the thermostatic valve and valve 6 open, the boiler starts to lose pressure, then that would be evidence that water from the boiler circuit is escaping somewhere. That means a leak, but since the hot tap water is discoloured, and since normally the only place where the two circuits can mix is a leaking coil, we are back to that again:( If the boiler doesn't lose pressure then we are chasing the wrong hare -- the colour can't be coming from the boiler circuit.

I would find it hard to believe that a new tank could have a leaking coil, but I suppose it isn't impossible.

brettmirl

ART6 wrote: »

OK so. If those pipes heat immediately then jamesm is correct. They are the boiler flow and return and the braided pipe is the coil bypass. In that case the pipe with the NR valve close to the braided hose must be the system make up from the attic tank, hence the NR valve. So another thing to test -- Immediately above the NR valve is a red handled screw valve. If you shut that then there will be no make up water getting to the boiler circuit (it shouldn't need to be open all the time anyway). If, with that valve closed and the thermostatic valve and valve 6 open, the boiler starts to lose pressure, then that would be evidence that water from the boiler circuit is escaping somewhere. That means a leak, but since the hot tap water is discoloured, and since normally the only place where the two circuits can mix is a leaking coil, we are back to that again:( If the boiler doesn't lose pressure then we are chasing the wrong hare -- the colour can't be coming from the boiler circuit.

I would find it hard to believe that a new tank could have a leaking coil, but I suppose it isn't impossible.

Hi Art6.

The plumber got me to close that red valve above the NR valve to see if it made any difference (it had been fully open). It's been closed since last night, so will see what happens.

ART6

brettmirl wrote: »

Hi Art6.

The plumber got me to close that red valve above the NR valve to see if it made any difference (it had been fully open). It's been closed since last night, so will see what happens.

Seems he is thinking along the same lines. So let's see what happens with the boiler pressure.

JamesM

ART6 wrote: »

Seems he is thinking along the same lines. So let's see what happens with the boiler pressure.

I've got a cold, so the head isn't working too well at the moment. But I agree with Art's recent posts. One other thing, if the pipe that the red valve and non return valve are on, comes from the same tank in the attic as the hot water, and not an expansion tank (is there an expansion vessel anywhere ?) then the water might have been pushing up past the non return valve and into that tank. Unlikely, but the brain is a bit frazzled at the moment.
Jim.

brettmirl

I turned on the boiler when I got home and checked which pipes got hot immediately. See attached pic for my dodgy editing!

Pressure ok so far and no change in water colour...it's not gotten any worse as yet.

brettmirl

JamesM wrote: »

I've got a cold, so the head isn't working too well at the moment. But I agree with Art's recent posts. One other thing, if the pipe that the red valve and non return valve are on, comes from the same tank in the attic as the hot water, and not an expansion tank (is there an expansion vessel anywhere ?) then the water might have been pushing up past the non return valve and into that tank. Unlikely, but the brain is a bit frazzled at the moment.
Jim.

Hey JamesM. A few hot whiskeys tonight will sort that cold for you!

I've checked the tank in the attic a few times since all this began, and each time the water in it has been clear.

That red valve abover the non return is currently closed.

ART6

brettmirl wrote: »

I turned on the boiler when I got home and checked which pipes got hot immediately. See attached pic for my dodgy editing!

Pressure ok so far and no change in water colour...it's not gotten any worse as yet.

OK. If the boiler circuit water was escaping into the tap water somewhere then with the red make up valve closed the system pressure would not increase when the boiler is on -- it would never rise above what it is with the boiler off. There would be some flow of water from the boiler circuit into the hot water system when the boiler lights and its water expands, and a flow in the other direction when the boiler is off and its water cools. That would suggest that the maximum flow between the two would probably be less than half a litre, so the end result might not be that the hot tap water clears completely, but only that it does a fair bit and doesn't get worse. So, does the pressure rise when the boiler lights or does it stay the same? If so, what is the gauge reading and how far above the floor on which the boiler stands it the bottom of the attic tank. I'm guessing that the cylinder is upstairs and the boiler is at ground level?

Oh, and JamesM I agree entirely with the OP about the cold treatment and would strongly recommend it. In fact I find that a steady supply of whiskey is an excellent preventative measure:D

JamesM

Thanks lads. One question, if the pipe no. 4 in Art's photo is the return from the coil to the boiler, why is it not hot ? Another, is the 1/2" pipe near the top of the cylinder the cold water feed to the cyl (fed down inside), or is there another connection on the right hand side at the bottom ? Or is that 1/2" pipe just another hot water pipe going to a shower or something. And, does the pipe with the red valve and NR valve go straight into the main tank in the attic.
Jim.

ART6

Going by the pic in OP's post #34 pipe #4 must be hot too since there doesn't seem to be anything to prevent it being. I just assumed he hadn't marked it. Since we believe we have identified the black levered valve on the braided hose as being the coil bypass, I wonder if opening it again would take some of the flow away from the coil and, if there's still a leak anywhere there, cut down on the water cross-over? Mind you, I haven't though that through!

brettmirl

ART6 wrote: »

So, does the pressure rise when the boiler lights or does it stay the same? If so, what is the gauge reading and how far above the floor on which the boiler stands it the bottom of the attic tank. I'm guessing that the cylinder is upstairs and the boiler is at ground level?

Hi ART6. Am in a typical 3 bed semi-d. The boiler is on the ground floor (wall mounted), the hot water cylinder is upstairs, and the water tank is in the attic.

The gauge reading on the boiler...there are two scales on it; one reads 0 to 4 and the other in red goes 0 to 60.

When the heating is off the needle is at zero. When I turn boiler, it immediately jumps to just below 1 (or 10 on the other scale) and when the heating reaches its top temp, the needles is at 1.5 (or 20).

After the boiler turns off, the needles slowly drops back to zero.

The boiler is a Sirrus Radiant RS20E.

items

Some of the advice here is way off the mark. Its hard to follow.

Two things worth mentioning, the flexi hose with the little black handle is a by-pass and should be open slightly. You have a heat control (thermo valve) on your cylinder flow, when cylinder is hot enough it shuts off circulation to the cylinder. The by-pass must always be open, if you happen to shut off the rads and turn on the boiler, you'll have no circulation. You'll damage pump at boiler or worse, blow up the boiler.

The red handle gate valve above the NRV(brass cylindrical fitting) is your heating filler, it must also remain open at all times.

brettmirl

JamesM wrote: »

Thanks lads. One question, if the pipe no. 4 in Art's photo is the return from the coil to the boiler, why is it not hot ? Another, is the 1/2" pipe near the top of the cylinder the cold water feed to the cyl (fed down inside), or is there another connection on the right hand side at the bottom ? Or is that 1/2" pipe just another hot water pipe going to a shower or something. And, does the pipe with the red valve and NR valve go straight into the main tank in the attic.
Jim.

Pipe #4 didn't get hot immediately like the pipes I marked did once the boiler came on.

items

The only place heating water can mix with hot water is inside the cylinder or related pipe work. Turning valves on and off wont solve the problem. The problem is being crated after the valves.

From what I believe you've had your cylinder replace? If so, that should rule out the cylinder.

It's possible heating pipe work and hot water pipework have some how been connected to each other, might have always been this way, you only notice now due to system being older, heating water has changed color over the years and only noticeable now.

To rule this out, your going to have to get a plumber to test heating system for leaks, easily done, connecting a hand pump with gauge to the heating system.

Like wise I would test the hot water pipe work for leaks, its another possibility. You could have a small leak in pipework under ground and its drawing in some dirt etc, giving the water that brown color.

Call the plumber back who replaced the cylinder, I am sure you got him/her in to fix the brown water problem, it doesn't seem to be fixed, he or she didn't do the job right and should return to do it right.


Just had a look at your pictures, you've a standard modern heating system, no big mysteries. Sometimes all the pipe work can throw people off, all you have to do is break it down. Heating pipe work comes directly into the hot press, from the hot press it is then divided to serve cylinder and rads. You've got some option of heating control which has only become available in Irish heating systems in the last 10 years or so.

You can choose to just heat your cylinder during the summer by turning off the rads (red lever action valve) when the cylinder is hot enough the thermocouple connected to the cylinder sends a signal to the thermo valve and it closes the valve stopping flow to the cylinder. This is why you must leave the by-pass open (black lever valve) to allow circulation to continue, with some small circulation your boiler will continue to run until it reaches set temp and then turn its self off.

brettmirl

Thanks items. Yes the cylinder is new and the gas boiler is only a few months old too. It was the same guy that installed both.

The plumber is due back next week. I think he is going to test for leaks. He said something about taking a tap off the pipes. He also said the non-return vavle might be faulty. Not sure if that would make a difference or not.

The brown water issue has been going on for about 2/3 months now. Like I said earlier in the thread, it all kicked off one day after the mains was cut to the whole town. Thought it was just some dirty mains water going through the system after the water was restored, but it never went away.

The water from the hot tap does run clear if I leave it run for about 30mins until all the hot water runs cold, but eventually it colours again. From the colour of the water, it does look like its mixing with rust or that brown water that comes out of rads.

Anyways, I'm really hoping to get it sorted before Christmas, cause it's getting to be a pain now!

JamesM

items wrote: »

Some of the advice here is way off the mark. Its hard to follow.

Two things worth mentioning, the flexi hose with the little black handle is a by-pass and should be open slightly. You have a heat control (thermo valve) on your cylinder flow, when cylinder is hot enough it shuts off circulation to the cylinder. The by-pass must always be open, if you happen to shut off the rads and turn on the boiler, you'll have no circulation. You'll damage pump at boiler or worse, blow up the boiler.

The red handle gate valve above the NRV(brass cylindrical fitting) is your heating filler, it must also remain open at all times.

A little bit dramatic, items. The red handled valve tops up the system and there is no problem leaving closed off for quite a long length of time, especially when trying to establish if there is a leak in the system.
We have already established that the braided hose is a bypass. In most systems, if all the rads are turned off, the water still bypasses them and will still circulate without any danger to the boiler. If the closing of any valve endangered the system, the valve should not be there.(As in the case of backboilers where there are no valves on the primary circuit).
Jim.

JamesM

Brettmirl, The water from rads and the heating system is often black, more than brown. If the pressure in the heating side of things is not dropping, then it is likely that the two systems are not linked. You could now open the red valve and see if the pressure is any different to when it was closed.
If we take it for a minute that the problem is not with the coil, but that the brown water is coming from somewhere else, can you establish where all the pipes on the right hand side are going to or coming from - could there be anything else in the water system that could be causing the problem.
Jim.

ART6

brettmirl wrote: »

Hi ART6. Am in a typical 3 bed semi-d. The boiler is on the ground floor (wall mounted), the hot water cylinder is upstairs, and the water tank is in the attic.

The gauge reading on the boiler...there are two scales on it; one reads 0 to 4 and the other in red goes 0 to 60.

When the heating is off the needle is at zero. When I turn boiler, it immediately jumps to just below 1 (or 10 on the other scale) and when the heating reaches its top temp, the needles is at 1.5 (or 20).

After the boiler turns off, the needles slowly drops back to zero.

The boiler is a Sirrus Radiant RS20E.

OK so. If the boiler pressure is dropping to zero with the boiler off, then two points -- Given the position of your cylinder in relation to the boiler, I wouldn't expect the pressure gauge to show much less than 4.5 (psi) on the red scale with the boiler off since that is the pressure that 10 ft of water in the pipes would create. If it drops to zero then that suggests to me that the expansion vessel (the red thingy like a squashed football in the boiler casing) has run out of air and needs to be pumped up using a foot pump or something connected to the valve like a car tyre valve on top of it.

If it rises to 20 psi when the boiler gets up to temperature than there can't be a coil leak. Assuming that water level in the attic tank is (say) 12 ft above the coil, then the water head pressure would be around 5 psi and the boiler would not be able to exceed that as the extra pressure would simply bleed off through the leak.

brettmirl wrote: »

Pipe #4 didn't get hot immediately like the pipes I marked did once the boiler came on.

If, as JamesM and I have concluded, pipe 4 is the boiler return, then it will gradually get hotter as the cylinder temperature rises. It's only pipe 3 that will heat up to full temperature immediately. So that is all normal.

JamesM wrote: »

Brettmirl, The water from rads and the heating system is often black, more than brown. If the pressure in the heating side of things is not dropping, then it is likely that the two systems are not linked. You could now open the red valve and see if the pressure is any different to when it was closed.
If we take it for a minute that the problem is not with the coil, but that the brown water is coming from somewhere else, can you establish where all the pipes on the right hand side are going to or coming from - could there be anything else in the water system that could be causing the problem.
Jim.

I agree. Only thing I would say is that I have known small amounts of boiler circuit water to get into expansion tanks, and although in quantity it is almost black, when diluted it does tend towards brown. In any case, if the boiler pressure is rising to 20 psi then there can't be a cross over into the tap water circuit as JamesM says and for the reasons I said above. So the discolouration must be coming from somewhere else.

And incidentally, even if you could close off both the radiators and the boiler circuit completely you still can't damage or blow up the boiler as its relief valve would simply open and blow off the pressure, generally through a pipe out through your wall.

items

JamesM wrote: »

A little bit dramatic, items. The red handled valve tops up the system and there is no problem leaving closed off for quite a long length of time, especially when trying to establish if there is a leak in the system.
We have already established that the braided hose is a bypass. In most systems, if all the rads are turned off, the water still bypasses them and will still circulate without any danger to the boiler. If the closing of any valve endangered the system, the valve should not be there.(As in the case of backboilers where there are no valves on the primary circuit).
Jim.

Heating filler should be left open when finished working with system, if its left closed eventually the heating system will be starved of water supply leading to rads with air in them.

Who ever plumbed the house decided to use a flexi for by-pass out of pure laziness. The by-pass valve should have its head removed after its opened slightly. same goes for the valve on the coil. Just because its got a head on it, doesn't mean you can turn it on and off.

Your saying "in most systems" I am talking about the system in this thread, the way the system here is set up, the by-pass must be left open. If the red lever handle (summer valve) is closed along with the by-pass valve the system has no circulation.

No dramatics here just advice from a qualified plumber with 15 years experience.

yoshytoshy

items wrote: »

Heating filler should be left open when finished working with system, if its left closed eventually the heating system will be starved of water supply leading to rads with air in them.

Who ever plumbed the house decided to use a flexi for by-pass out of pure laziness. The by-pass valve should have its head removed after its opened slightly. same goes for the valve on the coil. Just because its got a head on it, doesn't mean you can turn it on and off.

Your saying "in most systems" I am talking about the system in this thread, the way the system here is set up, the by-pass must be left open. If the red lever handle (summer valve) is closed along with the by-pass valve the system has no circulation.

No dramatics here just advice from a qualified plumber with 15 years experience.

Items ,your not the only qualified person that is on the site. And not all filler valves need to be left open.

I specifically don't leave valves on ,so I know I don't have any leaks on systems.

items

ART6 wrote: »

OK so. If the boiler pressure is dropping to zero with the boiler off, then two points -- Given the position of your cylinder in relation to the boiler, I wouldn't expect the pressure gauge to show much less than 4.5 (psi) on the red scale with the boiler off since that is the pressure that 10 ft of water in the pipes would create. If it drops to zero then that suggests to me that the expansion vessel (the red thingy like a squashed football in the boiler casing) has run out of air and needs to be pumped up using a foot pump or something connected to the valve like a car tyre valve on top of it.

If it rises to 20 psi when the boiler gets up to temperature than there can't be a coil leak. Assuming that water level in the attic tank is (say) 12 ft above the coil, then the water head pressure would be around 5 psi and the boiler would not be able to exceed that as the extra pressure would simply bleed off through the leak.



If, as JamesM and I have concluded, pipe 4 is the boiler return, then it will gradually get hotter as the cylinder temperature rises. It's only pipe 3 that will heat up to full temperature immediately. So that is all normal.



I agree. Only thing I would say is that I have known small amounts of boiler circuit water to get into expansion tanks, and although in quantity it is almost black, when diluted it does tend towards brown. In any case, if the boiler pressure is rising to 20 psi then there can't be a cross over into the tap water circuit as JamesM says and for the reasons I said above. So the discolouration must be coming from somewhere else.

And incidentally, even if you could close off both the radiators and the boiler circuit completely you still can't damage or blow up the boiler as its relief valve would simply open and blow off the pressure, generally through a pipe out through your wall.

Hope you have a few quid to cover further damages. If you run the boiler with no circulation a few problems on top of the problem you have could arise. Boiler running with no circulation could lead to blown pump motor, blown high limit stat, blown diaphragm in expansion vessel, seating on safety valve damage, scalding of the person walking past the boiler safety, thats if you are lucky enough to have it even piped outside.

If your interested in solving the problem carry on but turn the boiler stat to its lowest setting while working things out and leave the by-pass open slightly, once its left open you can turn on and off any other valves until your hearts content.

items

yoshytoshy wrote: »

Items ,your not the only qualified person that is on the site. And not all filler valves need to be left open.

I specifically don't leave valves on ,so I know I don't have any leaks on systems.

Filler left open and a gauge for checking pressure (other than boiler) is best should you be worried about leaks. A system installed correctly and pressure tested leaves no leaks to worry about.

A boiler filler valve should be left open, end of. Their should be no reason not to leave it open, if leaving it open causes a problem then their is a problem with the heating system.

yoshytoshy

Items ,is there any harm in topping up a heating system when it's hot ?