Central Heating issue

notahappycamper · 01-04-2013 9:19am #1

Hi,

We have our heating on in the mornings to heat the water. Then it comes on to heat the radiators. But lately, it will only heat the radiators upstairs but not downstairs if it has been heating the water first. You have to wait an hour or so after it been turned off and then turn just the heat on and it will work! Any ideas? Is there an airlock between upstairs and downstairs? Does the system need to be balanced again? Generally when the rads downstairs don't work there is a "whoosing" of water through the rads upstairs nearest the boiler when it has been initially turned on. The boiler is located upstairs by the way.

Thanks...

notahappycamper · 02-04-2013 9:05am

notahappycamper wrote: »

Hi,

We have our heating on in the mornings to heat the water. Then it comes on to heat the radiators. But lately, it will only heat the radiators upstairs but not downstairs if it has been heating the water first. You have to wait an hour or so after it been turned off and then turn just the heat on and it will work! Any ideas? Is there an airlock between upstairs and downstairs? Does the system need to be balanced again? Generally when the rads downstairs don't work there is a "whoosing" of water through the rads upstairs nearest the boiler when it has been initially turned on. The boiler is located upstairs by the way.

Thanks...

Any ideas folks?

oikster · 02-04-2013 11:20am

Most definitely air. A system plumbed like this has to be perfect or it will always give bother . The radiators on the lower floor are on a drop system in that either each individual pipe drops to lower level or at least two main pipes do.Air elimination is usually sorted out by automatic air vents or in some cases manually. The whooshing sound you are hearing is air in your pipework and pump. Whether this is a sealed system or an open one it may be best to call a plumber out as getting rid of all the air may take some time and knowhow.You can always have a go yourself but it can be frustrating.

notahappycamper · 02-04-2013 8:26pm

oikster wrote: »

Most definitely air. A system plumbed like this has to be perfect or it will always give bother . The radiators on the lower floor are on a drop system in that either each individual pipe drops to lower level or at least two main pipes do.Air elimination is usually sorted out by automatic air vents or in some cases manually. The whooshing sound you are hearing is air in your pipework and pump. Whether this is a sealed system or an open one it may be best to call a plumber out as getting rid of all the air may take some time and knowhow.You can always have a go yourself but it can be frustrating.

Plumber was out today. He thinks air is getting into the system continually and possibly through the heat-exchanger? Now one rad needs the bleed valve replaced as the head has been rounded off on it! So I dunno, could it be anything else? The boiler is a Glow Worm Flexicom 30sx. It's only about 3 years old.

sullzz · 02-04-2013 8:31pm

notahappycamper wrote: »

Plumber was out today. He thinks air is getting into the system continually and possibly through the heat-exchanger? Now one rad needs the bleed valve replaced as the head has been rounded off on it! So I dunno, could it be anything else? The boiler is a Glow Worm Flexicom 30sx. It's only about 3 years old.

Air in through the heat exchanger ? Deffo not !!
I presume your heating is a sealed system is sealed , do you have to repressurise it often or do you have an auto filling valve / pressure reducing valve

notahappycamper · 02-04-2013 8:39pm

sullzz wrote: »

Air in through the heat exchanger ? Deffo not !!
I presume your heating is a sealed system is sealed , do you have to repressurise it often or do you have an auto filling valve / pressure reducing valve

The pressure is currently 1 bar, although he did say the valve in the hot press for it was not working. I do have to bleed the rads upstairs a good bit - two stay roasting, the other stay 90% warm. How else could air be getting into the system if you need to bleed the rads often? The boiler is upstairs and the rads downstairs don't need to be bled often at all the upstairs ones are the issue. But the problem we have been having recently is that after the heat has been on to heat the water, it then heats the rads and the rads upstairs get hot but downstairs are cold! So, I turn off the heat altogether and wait then turn it back on and then it will heat all the rads!

sullzz · 02-04-2013 8:44pm

When you bleed the rads upstairs do you have to repressurise the system

notahappycamper · 02-04-2013 8:49pm

No.

sullzz · 02-04-2013 8:53pm

notahappycamper wrote: »

No.

Well then you have a pressure reducing valve or an auto filling valve which is hiding a leak on your system which will ruin your 3year old boiler in no time , you should get this valve removed and see how long it takes for your system to drop to 0 bar , how often do you have to bleed your upstairs rads?

oikster · 02-04-2013 9:10pm

When you or your plumber were trying to vent your system,was it on or off,hot or cold because if the system was running and hot you wouldn't have a hope of venting it properly. You mentioned a radiator with a broken vent, how long has this been broken? Is your house timber framed and are the pipes run in the walls, if so surely you would see a leak.

sullzz · 02-04-2013 9:23pm

oikster wrote: »

When you or your plumber were trying to vent your system,was it on or off,hot or cold because if the system was running and hot you wouldn't have a hope of venting it properly. You mentioned a radiator with a broken vent, how long has this been broken? Is your house timber framed and are the pipes run in the walls, if so surely you would see a leak.

Boiler is located upstairs with 1 bar pressure , so its a sealed system , he has to bleed the upstairs rads a good bit and never has to repressurise the system , so there is an auto filling valve , a lot of air getting into the system means water is getting out , so there is a leak , could be the coil if all pipework is above ground

oikster · 02-04-2013 9:32pm

sullzz wrote: »

Boiler is located upstairs with 1 bar pressure , so its a sealed system , he has to bleed the upstairs rads a good bit and never has to repressurise the system , so there is an auto filling valve , a lot of air getting into the system means water is getting out, so there is a leak , could be the coil if all pipework is above ground

The only other thing I have ever come across was a leak at the boiler which only leaked very little and the heat of the boiler evaporated it. Made it very difficult to find.But I still think it hasn't been bled properly going by the suggestion that air was coming in through the heat exchanger.

sullzz · 02-04-2013 9:35pm

I have seen that too but if his boiler is upstairs its surely higher than his rads

notahappycamper · 02-04-2013 9:37pm

sullzz wrote: »

Well then you have a pressure reducing valve or an auto filling valve which is hiding a leak on your system which will ruin your 3year old boiler in no time , you should get this valve removed and see how long it takes for your system to drop to 0 bar , how often do you have to bleed your upstairs rads?

He's turned off the valve in the hot press, so I'll check to see how long it's takes to drop to zero. Also, the valve in the valve in the hot press for the hot water cylinder needs to be bled also.

Any reason why it's only the rads upstairs that need bleeding a lot? The rads downstairs are generally fine and need no or little bleeding. The boiler is located upstairs.

Thanks for replies and help so far!

sullzz · 02-04-2013 9:41pm

To me it sounds like a bad enough leak , rads upstairs and cylinder are highest point on the aystem , id double check that he turned the supply valve off mabey post a pic

oikster · 02-04-2013 9:43pm

Yes thought about that one too. But I have seen plenty systems in timber framed buildings albeit with the boilers downstairs giving terrible trouble with air and no sign of a leak. What about cavitation at the pump.

notahappycamper · 02-04-2013 9:53pm

Will post pics tomorrow. If its a flaming leak it'll be hard to find!

Billy Bunting · 02-04-2013 9:56pm

notahappycamper wrote: »

Any ideas folks?

Is it a presurised system ? sounds like a pump or balancing issue, i bit more info and pictures would help further.

notahappycamper · 02-04-2013 10:03pm

Billy Bunting wrote: »

Is it a presurised system ? sounds like a pump or balancing issue, i bit more info and pictures would help further.

I think its presurised. Water pressure is at 1.0 bar. Will post pics tomorrow.

notahappycamper · 03-04-2013 7:34am

Pics as requested, cant post them in a single post.

notahappycamper · 03-04-2013 7:35am

Pics:

notahappycamper · 03-04-2013 7:37am

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notahappycamper · 03-04-2013 7:37am

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notahappycamper · 03-04-2013 7:38am

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notahappycamper · 03-04-2013 7:38am

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notahappycamper · 03-04-2013 7:39am

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notahappycamper · 03-04-2013 7:45am

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oikster · 03-04-2013 4:39pm

Some pretty strange looking stuff happening here.Balancing valve for hot water coil can effectively kill supply to the system. Why is there a great big non-return valve on the fill. Looks like a starvation of water to me. But the way this is piped it is hard to know.Auto air vent would have been nice on the coil,a decent one that is. I wonder where the pump and motorised valves are.

I just checked out that boiler and it is a gas system boiler. At least I know where the pump is . Maybe one of the gas lads can shine some light here.

notahappycamper · 03-04-2013 5:08pm

oikster wrote: »

Some pretty strange looking stuff happening here.Balancing valve for hot water coil can effectively kill supply to the system. Why is there a great big non-return valve on the fill. Looks like a starvation of water to me. But the way this is piped it is hard to know.Auto air vent would have been nice on the coil,a decent one that is. I wonder where the pump and motorised valves are.

I just checked out that boiler and it is a gas system boiler. At least I know where the pump is . Maybe one of the gas lads can shine some light here.

The motorised valves are under the boiler.

oikster · 03-04-2013 7:13pm

What if the expansion vessel is bust and the pressure in the system is exceeding the safety valve. This would cause water to be ejected from the system and replaced by the filling loop,which should not be permanently connected ,back into the system.This could cause air to become trapped in the pipework.But unless your safety valve pipework is piped outside this will not be the case because you would see the water.

oikster · 03-04-2013 7:30pm

notahappycamper wrote: »

Pic:

What is happening here????:eek:

Sorry 5th pic down.

notahappycamper · 03-04-2013 7:54pm

oikster wrote: »

What is happening here????:eek:

Sorry 5th pic down.

I don't know! What do you mean exactly?

oikster · 03-04-2013 8:00pm

Sorry again it was actually 6th pic down where it appears that the fill into your system is connected to a plumbing pipe ,permanently connected and relying on a swing non return valve to stop backflow.This is wrong on so many levels. Regs or no regs.

notahappycamper · 03-04-2013 8:08pm

oikster wrote: »

Sorry again it was actually 6th pic down where it appears that the fill into your system is connected to a plumbing pipe ,permanently connected and relying on a swing non return valve to stop backflow.This is wrong on so many levels. Regs or no regs.

Why? What could happen and why do you think it was done in the first place?

oikster · 03-04-2013 8:19pm

A pressurised or sealed heating system is normally filled from the mains using a temporary flexble connection (connect to fill-remove when finished). Thewater also passes through a double check valve to ensure that no heating system water can backflow into the main.This is standard water regulation.
Yours on the other hand appears to be connected into your cold supply to your bathroom cold taps .toilet,showers etc.
The strange bit is, you say your heating system is at 1 bar. Is this hot or cold pressure reading?

notahappycamper · 03-04-2013 8:55pm

oikster wrote: »

A pressurised or sealed heating system is normally filled from the mains using a temporary flexble connection (connect to fill-remove when finished). Thewater also passes through a double check valve to ensure that no heating system water can backflow into the main.This is standard water regulation.
Yours on the other hand appears to be connected into your cold supply to your bathroom cold taps .toilet,showers etc.
The strange bit is, you say your heating system is at 1 bar. Is this hot or cold pressure reading?

Sorry, I was wrong about the system water pressure! I brought up the fault code log! When i try to bring up the pressure throgh the diagnostic menu it skips over the no. for the water pressure. It says the pressure is shown permanently when the system is off but I think ours is in stand by on account of the motorised valves. So can you tell me how to get the water pressure?

oikster · 03-04-2013 9:07pm

Sorry I do not work on gas boilers so can't help there I'm afraid. Under normal circumstances topping up a sealed system is a simple procedure but in this case I am looking at pipe arrangements that I do not recognise. Maybe some of the gas lads on here can help you. If its any consolation I still do not think that your problem is a leak.

I have also downloaded the installation manual for this boiler and of the three suggested methods of filling the system none is remotely like yours I'm afraid

notahappycamper · 04-04-2013 6:27pm

So can anyone recommend a plumber to fix the problem with the central heating. Are c&f quadrant any good?

oikster · 04-04-2013 6:58pm

Can you think of any reason that none of the lads on here are willing to help you? Strange I must say.

notahappycamper · 04-04-2013 7:02pm

oikster wrote: »

Can you think of any reason that none of the lads on here are willing to help you? Strange I must say.

None! Maybe as I don't post much in the Plumbing and Heating forum?!!

oikster · 04-04-2013 7:04pm

Seemed to be quite a few offers up until you posted those pics.

notahappycamper · 04-04-2013 7:09pm

oikster wrote: »

Seemed to be quite a few offers up until you posted those pics.

Ha! Is it that a bad of a set up in my hot press?!

oikster · 04-04-2013 7:21pm

Mostly it is OK, but that fill pipe , if that is what it is. just doesn't look right.

Billy Bunting · 04-04-2013 7:34pm

oikster wrote: »

Can you think of any reason that none of the lads on here are willing to help you? Strange I must say.

I imagine that most had thought you had it all covered and as its now gone 3 pages and been made a tad confusing most just can't be asked to catch up on it.

:eek:

oikster · 04-04-2013 7:42pm

Billy Bunting wrote: »

Is it a presurised system ? sounds like a pump or balancing issue, i bit more info and pictures would help further.

Have you seen the pictures that you asked for?

oikster · 04-04-2013 8:07pm

Apologies OP that I cannot take this any further.But rest assured that I will find out how common or not ,this type of connection is.

oikster · 04-04-2013 8:52pm

A wee bit more info OP. What you seem to have is an ATTEMPT at a semi sealed system. Seems to be recommended by some gas boiler manufacturers. Although a dedicated top up tank should be installed.What you have is a shortcut.The bare minimum pressure to keep the boiler satisfied,yet not enough to annoy any existing dodgy fittings.In other words OP the LAZY way out.I take it from the silence on here that this is common practice. And then they cry about regulations and unregistered workmen. Hard to beat a bit of experience.:D

JohnnieK · 05-04-2013 9:02pm

The fill valve on the system is a 1/2 inch 367 valve. If it is hooked up to the mains 10 times out of 10 these valves will pass when closed on mains pressure. Are you sure it's connected to the mains? Flexicoms can be configured to work on low pressure systems.
You could follow the 1/2inch pipe into the attic and see where it terminates.

First I would get that set up changed for a proper filling loop. Then see if the pressure drops.

Then I would get the coil on the cylinder capped to see if the coil has a pin hole in it.

Also has your RGI checked the boiler expansion vessel and safety valve? The valve should be piped to the outside and should be 1/2inch copper. It will be outside in the location of the boiler.

Central Heating issue

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