Not great on boilers, but with our boiler unit, the problem was with a motor not opening the right valve to get the flow going.
Do you hear a small gearing noise that opens a valve when you start the boiler ?
If the boiler doesn't engage when you don't hear it, then its probably that and it cost us 100 odd to replace, maybe more....
How old is it?
Has it ever been serviced?
i love armchair boiler experts
my house was built in 2000 and came with a potterton boiler, after a few years we kept getting the red flashing light you describe, press reset and it'd work for a while then trip out again. A bit of googling suggested a faulty circuit board. Not adverse to taking things apart I stripped the old one out and the board looked like it had been soldered by a 3 year old blind kid, it was shoddy.
Re-soldered all the dry joints and got another 3 years out of it. Bit the bullet and ordered another board from the Bay, which was a pukka potterton board for £100. The board had been redesigned and of better quality and to this day not had a problem.
Turns out Potterton boilers were reknowned for it, even made Watchdog!
could be the same for you?
my house was built in 2000 and came with a potterton boiler, after a few years we kept getting the red flashing light you describe, press reset and it'd work for a while then trip out again. A bit of googling suggested a faulty circuit board. Not adverse to taking things apart I stripped the old one out and the board looked like it had been soldered by a 3 year old blind kid, it was shoddy.
Re-soldered all the dry joints and got another 3 years out of it. Bit the bullet and ordered another board from the Bay, which was a pukka potterton board for £100. The board had been redesigned and of better quality and to this day not had a problem.
Turns out Potterton boilers were reknowned for it, even made Watchdog!
could be the same for you?