Hello. My heating works fine. My problem is my hot water.
When you run a tap the boiler lights, goes into high flame, temp rises to approx 35 degrees then the flame goes out & doesn't modulate (modulation works fine on heating). Temp drops as the water still pumps, fan is also still operating (which rules out pressure switches i think), then the boiler fires up again, temp rises and flame cuts out again at the same temp. A combi engineer has looked at the boiler and gave up!
He has replaced all thermistors, i have stripped and cleaned the diverter valve. I have also replaced the PCB with a spare, it has had a new main heat exchanger fitted (fault occured previous to this).
Fault totally baffles me as everything works ok on heating and doesn't this rule out most parts apart from the thermistors & PCB??
Please help as on the verge of spending a lot of money on a new boiler as i refuse to spend any more cash unless i can pin down a definate cause.
Any comments/help will be welcome.
When you run a tap the boiler lights, goes into high flame, temp rises to approx 35 degrees then the flame goes out & doesn't modulate (modulation works fine on heating). Temp drops as the water still pumps, fan is also still operating (which rules out pressure switches i think), then the boiler fires up again, temp rises and flame cuts out again at the same temp. A combi engineer has looked at the boiler and gave up!
He has replaced all thermistors, i have stripped and cleaned the diverter valve. I have also replaced the PCB with a spare, it has had a new main heat exchanger fitted (fault occured previous to this).
Fault totally baffles me as everything works ok on heating and doesn't this rule out most parts apart from the thermistors & PCB??
Please help as on the verge of spending a lot of money on a new boiler as i refuse to spend any more cash unless i can pin down a definate cause.
Any comments/help will be welcome.