Hoping someone can help. This boiler is really starting to annoy me now thankfully I have insurance on it but the engineers who come out have sometimes been clueless.
Over the last few years it's had main Pcb replaced, new heat exchanger, fan unit and various other things. The last repair was a month ago and was the main pcb that had blown. Now we have started to use the heating because it's got colder I've noticed the radiators take ages to get hot and then when they do they go cool for a while and the burner doesn't come back in for a while.
When it does kick back in the display shows the flow temperature going up very quickly (it's set at about 50c sometimes lower) and then the flow temp can hover at like 51c then you'll see it drop to 48c then back upto 52c and will jump up and down like that and then the burner cycles off.
It never used to do this the boiler burner could be on for about half an hour sometimes longer just ticking away modulated down low. All the radiators are fully on in the house so there should be plenty of flow. I've tried turning the flow temp up but it does the same pretty much.
When the burner is off the flow temp quickly starts dropping and then the fluttering of temp on the display occurs it will flicker between 42-38c then backup 40 then may go back down to 38 before going back upto 41c.
I'm pretty sure there is no blockage it was all drained down the other year to replace the trv's in the house and inhibitor fitted. The heat exchanger was replaced after this though as it was blocked about a year ago.
What could possibly wrong with it? Thank you.
Over the last few years it's had main Pcb replaced, new heat exchanger, fan unit and various other things. The last repair was a month ago and was the main pcb that had blown. Now we have started to use the heating because it's got colder I've noticed the radiators take ages to get hot and then when they do they go cool for a while and the burner doesn't come back in for a while.
When it does kick back in the display shows the flow temperature going up very quickly (it's set at about 50c sometimes lower) and then the flow temp can hover at like 51c then you'll see it drop to 48c then back upto 52c and will jump up and down like that and then the burner cycles off.
It never used to do this the boiler burner could be on for about half an hour sometimes longer just ticking away modulated down low. All the radiators are fully on in the house so there should be plenty of flow. I've tried turning the flow temp up but it does the same pretty much.
When the burner is off the flow temp quickly starts dropping and then the fluttering of temp on the display occurs it will flicker between 42-38c then backup 40 then may go back down to 38 before going back upto 41c.
I'm pretty sure there is no blockage it was all drained down the other year to replace the trv's in the house and inhibitor fitted. The heat exchanger was replaced after this though as it was blocked about a year ago.
What could possibly wrong with it? Thank you.
