Hello everyone.
I've been a lurker on these forums for a while but I've never made a post.
My cousin's had a lot of problems with her boiler, which I've been tring to resolve for her, as several
plumbers ripped her off. It looks like I've resolved the problems finally, largely due to the helpful
posts which I have read on this forum.
I would therefore briefly like to summarise my findings, in the hope it helps someone else in the future, who
may be having similar problems. Winter is not a time to have no heating.
The boiler is a Vaillant Eco Max 824/2E condensing boiler.
The symptoms where daily loss of pressure and subsequent system shut down = cold house
My findings are:
Firstly we had some leaks:
Copper pipe couplers with 'gate / shut off' valves (compression fit). These leak. This one in particular leaked
from the slotted gate on / off control. Keep an eye on them and if buying replacements, get quality ones.
Vaillant central heating service valves. Specifically, the valves which connect the flow and return pipes to the
boiler itself. These leak. The valves have a drain facility operated by a slotted gate control. Someone before me
must have operated this valve and caused the leak. The leak came from the slotted control itself.
I've read this is common with Vaillant, so never ever operate these valves.
When buying vaillant only valves shop around. We saved about £80 this way.
So once these leaks were fixed, we still had pressure loss. This was due to two reasons:
1 - Pressure releif valve. It seems she was inadvertently overpressurising the boiler on a daily basis and this valve was regularly opening.
As many people have said on these forums, when these valves open the often do not close properly again. We replaced this valve.
Again, we shopped around.
2 - Expansion vessel: We noticed that when the heating came on the pressure went through the roof - way above the cold 1.5 bar
it should be. This would obviously cause the PRV to open and loose some water, hence inviting a system shutdown when cold.
After reading these forums, I learnt to remove the boiler's cover and re-charge the vessel. When I checked it was totally devoid
of any air but full of water. (The membrane is OK though as none came from the valve).
The only wrinkle was that to drain down I had a disconnect a radiator valve as there was no drain point.
I've replaced the said valve with one that has a drain cock now so draining down should be easier in future.
Re-charging the vessel was really simple, anyone could do it. Simply a tyre pump and pressure gauge was required. The system works well now.
I do have one question for anyone out there: The car type valve on the vessel: when I pressrised the vessel, the valve very slightly hisses, until
I replace the dust cap. I'm guessing the pin isn't popping far enough out to close the valve fully. Can these valves be replaced? I'm worried that in a few weeks / months this air may be lost. The dust cap seems to be holding it (I put some spit on it - no bubbles) but I'm not sure. Failing that I guess I could get some pointy nose pliers and work the central pin in and out.
I hope this helps someone, the money a plumber would have charged for this work doesn't bear thinking about.
Thanks again.
I've been a lurker on these forums for a while but I've never made a post.
My cousin's had a lot of problems with her boiler, which I've been tring to resolve for her, as several
plumbers ripped her off. It looks like I've resolved the problems finally, largely due to the helpful
posts which I have read on this forum.
I would therefore briefly like to summarise my findings, in the hope it helps someone else in the future, who
may be having similar problems. Winter is not a time to have no heating.
The boiler is a Vaillant Eco Max 824/2E condensing boiler.
The symptoms where daily loss of pressure and subsequent system shut down = cold house
My findings are:
Firstly we had some leaks:
Copper pipe couplers with 'gate / shut off' valves (compression fit). These leak. This one in particular leaked
from the slotted gate on / off control. Keep an eye on them and if buying replacements, get quality ones.
Vaillant central heating service valves. Specifically, the valves which connect the flow and return pipes to the
boiler itself. These leak. The valves have a drain facility operated by a slotted gate control. Someone before me
must have operated this valve and caused the leak. The leak came from the slotted control itself.
I've read this is common with Vaillant, so never ever operate these valves.
When buying vaillant only valves shop around. We saved about £80 this way.
So once these leaks were fixed, we still had pressure loss. This was due to two reasons:
1 - Pressure releif valve. It seems she was inadvertently overpressurising the boiler on a daily basis and this valve was regularly opening.
As many people have said on these forums, when these valves open the often do not close properly again. We replaced this valve.
Again, we shopped around.
2 - Expansion vessel: We noticed that when the heating came on the pressure went through the roof - way above the cold 1.5 bar
it should be. This would obviously cause the PRV to open and loose some water, hence inviting a system shutdown when cold.
After reading these forums, I learnt to remove the boiler's cover and re-charge the vessel. When I checked it was totally devoid
of any air but full of water. (The membrane is OK though as none came from the valve).
The only wrinkle was that to drain down I had a disconnect a radiator valve as there was no drain point.
I've replaced the said valve with one that has a drain cock now so draining down should be easier in future.
Re-charging the vessel was really simple, anyone could do it. Simply a tyre pump and pressure gauge was required. The system works well now.
I do have one question for anyone out there: The car type valve on the vessel: when I pressrised the vessel, the valve very slightly hisses, until
I replace the dust cap. I'm guessing the pin isn't popping far enough out to close the valve fully. Can these valves be replaced? I'm worried that in a few weeks / months this air may be lost. The dust cap seems to be holding it (I put some spit on it - no bubbles) but I'm not sure. Failing that I guess I could get some pointy nose pliers and work the central pin in and out.
I hope this helps someone, the money a plumber would have charged for this work doesn't bear thinking about.
Thanks again.
