Hi, I have an annoying problem with a Baxi 80 eco. I am losing pressure over a few days, I have checked the system for leaks and found a few (some quite bad) and fixed these but it seems to have made the pressure drop even quicker. Have also replaced the pressure relief valve and some o rings that seal the pump but still losing pressure. Another problem that has developed is a groaning/whistling noise when the pressure gets to 1 bar which is cured by filling the system up to 2 bar. I have bought some fernox leak sealer but I am reluctant to put it in as the problem must be quite major for the pressure to drop so quickly. The boiler is in the loft so it is a pain to keep filling. Any advise would be greatly appreciated.
need help with pressure problem
- Thread starter m.900
- Start date
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Does any of the pipework run underneath the ground floor?
Have you checked for leaks when the system is stone cold and up to pressure? You could bring the pressure up to 2 bar to make such leaks more obvious, then release the excess before firing the boiler.
Have you checked for leaks when the system is stone cold and up to pressure? You could bring the pressure up to 2 bar to make such leaks more obvious, then release the excess before firing the boiler.
Have had floorboards up yesterday and checked all pipes cold and with heating on and everything is bone dry. We usually run it around 2 bar.
Have you checked all rad valves when the system is cold?
A common first step is to isolate the flow and return at the boiler.
However (and as someone would otherwise leap to point out), those isolating valves rarely work without subsequently leaking, and often don't work anyway.
That aside, if you have the means of isolating the flow and return, then you'll find out if the pressure holds or drops. If it drops then the leaks is in/at the boiler, if it holds then the leak is in the pipework (or rads) somewhere.
A common first step is to isolate the flow and return at the boiler.
However (and as someone would otherwise leap to point out), those isolating valves rarely work without subsequently leaking, and often don't work anyway.
That aside, if you have the means of isolating the flow and return, then you'll find out if the pressure holds or drops. If it drops then the leaks is in/at the boiler, if it holds then the leak is in the pipework (or rads) somewhere.
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Have checked the rad valves yesterday and found one that had a slight leak. I have tightened it up and its now ok but the pressure has still dropped from 2bar to 1.5 during this afternoon.
Whilst searching for leaks around the boiler, the girlfriend mentioned that the pressure seems to drop quicker after running a bath. On further investigation the pressure does not seem to rise when the heating is turned on but jumps (0.5bar) up almost immediatly when the hot tap is turned on. Does this help to shed any light on the problem or is this normal???
After my last post I realised I was wrong about the pressure going up when the heating is turned on, it does by about 1 bar but the pressure jumps up still when the hot tap is turned on.
I have now also turned off the boiler, pressured the system up to 2 bar, isolated the flow and return valves and left it while at work. When I got home tonight the pressure had dropped nearly 1 bar
I have now also turned off the boiler, pressured the system up to 2 bar, isolated the flow and return valves and left it while at work. When I got home tonight the pressure had dropped nearly 1 bar
I forgot to mention that this result could also be caused by the isolating valves failing. After the pressure has dropped by 1 bar, with the valves shut, if you open again then either (a) the pressure will stay the same, in which case the valves were leaking, or (b) the pressure will increase, in which case the boiler was leaking.m.900 said:
My money is on the valves failing and the leak therefore being somewhere in the pipework/rads/rad valves.
Sorry to be a pain, but I've spent all yesterday looking round the whole of the system for leaks and can find any.I've also put on a new PRV just to be sure it's not that and checked the expansion vessels not got water in and repressured that. The pressure has still droped 1 bar over the day. Surely for the pressure to drop that quickly there must be a big puddle or water staining somewhere.
Sorry again to keep asking questions but why would the pressure rise when the hot tap is turned on, is there any way there could be a leak from the dhw to the central heating circuit or the other way round and therefore not show as a external leak.
One final question, what are your views on using fernox leak sealer as I'm thinking of trying it as a last resort.
Sorry again to keep asking questions but why would the pressure rise when the hot tap is turned on, is there any way there could be a leak from the dhw to the central heating circuit or the other way round and therefore not show as a external leak.
One final question, what are your views on using fernox leak sealer as I'm thinking of trying it as a last resort.
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