baxi combi 105e

I have a problem with the central heating and hot water supply which is getting worse.
Sometimes I have central heating and hot water, sometimes cental heating only and sometimes hot water only.
When their is a fault the No8 50º red neon light flashes and the No 15 burner on symbol flashes amber.
The pump runs when there is no heating,and tends to right itself after an hour or two.
First thing in the morning everything is OK for the first couple of hours.
I have a thermostat fitted in the hall.

I would be most grateful for any ideas.

Regards, Brian Prince.

Flashing 50 usually indicates a pcb fault if not a fan/air fault which it's meant to.
Haven't heard of the other faults at the same time though, so would investigate by watching exactly what's going on internally when it isn't doing the right thing.

I'd probably try a new pcb first - easy when you have several...

if the pump is running then you would have to look at has the pump proved first, then work through the sequence.

look inside at the divertor valve and see if the second plunger( the one at the back)is making the switch if yes then aps problem or blocked venturi maybe????

you have to work out at what point is the boiler sequence failing how old is the boiler?

65% of baxi pcb which are return via heat team have no fault found so i have been told!!

ChrisR said:

I'd probably try a new pcb first - easy when you have several...

Click to expand...

Agreed PCB is req'd






I don't have a ° but I do have PCBs