Hi, I wonder if anyone can give me advice on the problem I am having of varying central heating pressure ?
I have a Vaillant ecoTEC plus 937 boiler. Even since installation (3 years ago) there has been a small pressure loss from the system requiring a "top-up" every two to three months. This I could live with (bearing in mind I couldn't see a leak anywhere visible)
My current problem is that the last time I re-pressurised to 1.3 bar I noticed that after 30 to 40 mins the pressure had risen to 3.0 bar and error code S 42 was showing (Pressure > 2.9 bar). I let 0.5 ltr out of system, pressure back to 2.2 bar.
Next morning no heating F24 displayed and 0.4 bar showing, presurised to 0.8 bar, boiler started but at full temperature (62 C) showed 2.6 bar.
Why is the pressure changing so much ?
I have checked the expansion vessel (pressed the valve, no water came out and there was pressure in it).
I had the plumber who installed the system look at it, he is now saying that he thinks the system needs a secondary expansion tank ! why ? It has been fine for 3 years and we have made no additions to the system since it was installed !
Any advise , things to try greatly appreciated.
I was told to half empty one of the rads to allow the other half to behave like a secondary expansion vessel, haven't tried it yet, thought I would ask here first.
I have a Vaillant ecoTEC plus 937 boiler. Even since installation (3 years ago) there has been a small pressure loss from the system requiring a "top-up" every two to three months. This I could live with (bearing in mind I couldn't see a leak anywhere visible)
My current problem is that the last time I re-pressurised to 1.3 bar I noticed that after 30 to 40 mins the pressure had risen to 3.0 bar and error code S 42 was showing (Pressure > 2.9 bar). I let 0.5 ltr out of system, pressure back to 2.2 bar.
Next morning no heating F24 displayed and 0.4 bar showing, presurised to 0.8 bar, boiler started but at full temperature (62 C) showed 2.6 bar.
Why is the pressure changing so much ?
I have checked the expansion vessel (pressed the valve, no water came out and there was pressure in it).
I had the plumber who installed the system look at it, he is now saying that he thinks the system needs a secondary expansion tank ! why ? It has been fine for 3 years and we have made no additions to the system since it was installed !
Any advise , things to try greatly appreciated.
I was told to half empty one of the rads to allow the other half to behave like a secondary expansion vessel, haven't tried it yet, thought I would ask here first.