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Brown Hot Water

  • 07-12-2009 10:25am
    #1
    Registered Users Posts: 2,429 ✭✭✭


    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?


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Comments

  • Registered Users Posts: 2,632 ✭✭✭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!


  • Registered Users Posts: 2,429 ✭✭✭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!


  • Registered Users Posts: 2,632 ✭✭✭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.


  • Registered Users Posts: 2,429 ✭✭✭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!


  • Registered Users Posts: 2,632 ✭✭✭ART6


    No bother. Hope it works out for you!


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  • Registered Users Posts: 2,429 ✭✭✭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?


  • Registered Users Posts: 2,632 ✭✭✭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;)


  • Closed Accounts Posts: 336 ✭✭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.


  • Registered Users Posts: 2,429 ✭✭✭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.


  • Registered Users Posts: 2,429 ✭✭✭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?


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  • Closed Accounts Posts: 3,305 ✭✭✭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.


  • Registered Users Posts: 2,429 ✭✭✭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!


  • Registered Users Posts: 2,632 ✭✭✭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.


  • Closed Accounts Posts: 3,305 ✭✭✭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.


  • Registered Users Posts: 1,775 ✭✭✭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.


  • Registered Users Posts: 2,429 ✭✭✭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.


  • Registered Users Posts: 2,632 ✭✭✭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!


  • Registered Users Posts: 2,429 ✭✭✭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.


  • Registered Users Posts: 2,632 ✭✭✭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


  • Registered Users Posts: 1,775 ✭✭✭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 :confused:
    Jim


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  • Registered Users Posts: 2,632 ✭✭✭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 :confused:
    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?


  • Registered Users Posts: 1,775 ✭✭✭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.


  • Registered Users Posts: 2,429 ✭✭✭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.


  • Registered Users Posts: 2,632 ✭✭✭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!


  • Registered Users Posts: 2,429 ✭✭✭brettmirl


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


  • Registered Users Posts: 2,429 ✭✭✭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?


  • Registered Users Posts: 2,632 ✭✭✭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.


  • Registered Users Posts: 2,429 ✭✭✭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.


  • Registered Users Posts: 2,632 ✭✭✭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.


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  • Registered Users Posts: 2,429 ✭✭✭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.


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