BAXI 105 HE PRESSURE KEEPS FALLING

[KEV KJ]

hi
i have a baxi 105 he, 16 months old. i keep finding that the pressure keeps falling, about once a day. the neon for pump/low pressure flashes and the boiler needs resetting. i fill the system to 2 bar, it heats upto 3 (overflows) then drops untill it reaches 0 and cuts out. from filling to refilling is about 24hrs.
i have checked the radiators, i cant find a leak, the times this is happening i would be swimming if it was a leak.

installer came out today, said it was the blow off valve (pressure) would get a new one for £20 (£60 fitted) as its outside of warranty (12 month). hope this dose it .

 

[Bryan King]

fill boiler to 1.5 bar if expansion takes it up to 3 bar(when hot) then the expansion vessel is failing.

the prv maybe faulty and leaking, hence pressure drop, but to be honest this is quite rare.

 

[kevplumb]

fill boiler to 1.5 bar if expansion takes it up to 3 bar(when hot) then the expansion vessel is failing.

depends on the system volume

the prv maybe faulty and leaking, hence pressure drop, but to be honest this is quite rare.