Apologies, this was posted in the wrong place.
Hi,
I have a Vaillant EcoTech 624 system boiler, around 7 years old.
Last week after having the boiler serviced (which inluded re-pressurising the expansion vessel), and when we first starting using the CH again after the summer and first cold weather, the CH worked OK for a day or two. But the next day the pressure plummeted to 0.2 with an F22 fault code.
I have since bled the radiators (there was some air in the rads high up in the house) and added water to the system up to around 1 bar. If I then switch on the CH it runs OK, but after it shuts down the pressure falls again all the way down to 0.0!
I checked the PRV, and the waste pipe is completely dry, so no water has been discharged.
Today I bled the radiators again just to make sure, with the system being stone cold, and then filled up to 1.4 bar and started the CH. The pressure went up to 2.1, as expected, but then steadily started to fall while the CH was running down to 0.7, at which point I thought it better to switch it off.
I know that all this suggests a leak, but there are no signs of a leak anywhere.
What is odd is that if I add water, and don’t switch on the CH for a few hours, the pressure holds steady and does not drop. How come? (This BTW surely also indicates that there is no leak.)
What I don't understand is where all the water goes that has been added when topping up.
Is it possible that after not using the CH for many months the system has somehow lost water?
Any help anyone can offer will be appreciated!
Seb
Hi,
I have a Vaillant EcoTech 624 system boiler, around 7 years old.
Last week after having the boiler serviced (which inluded re-pressurising the expansion vessel), and when we first starting using the CH again after the summer and first cold weather, the CH worked OK for a day or two. But the next day the pressure plummeted to 0.2 with an F22 fault code.
I have since bled the radiators (there was some air in the rads high up in the house) and added water to the system up to around 1 bar. If I then switch on the CH it runs OK, but after it shuts down the pressure falls again all the way down to 0.0!
I checked the PRV, and the waste pipe is completely dry, so no water has been discharged.
Today I bled the radiators again just to make sure, with the system being stone cold, and then filled up to 1.4 bar and started the CH. The pressure went up to 2.1, as expected, but then steadily started to fall while the CH was running down to 0.7, at which point I thought it better to switch it off.
I know that all this suggests a leak, but there are no signs of a leak anywhere.
What is odd is that if I add water, and don’t switch on the CH for a few hours, the pressure holds steady and does not drop. How come? (This BTW surely also indicates that there is no leak.)
What I don't understand is where all the water goes that has been added when topping up.
Is it possible that after not using the CH for many months the system has somehow lost water?
Any help anyone can offer will be appreciated!
Seb
