Baxi Duo Tec HE 40 heating issue

[zak20vt]

The problem I'm having is that occasionally, when the heating is switched on, the green 'radiator/heating' light comes on on the boiler, but not the amber 'flame' light.

While the boiler is on this state, radiators don't get warm.

If I turn the boiler off and back on, the heating kicks in as it should.

The controls until recently were the Boss Therm brtrf wireless thermostat, and this weekend I swapped it out for a Hive 2. Same problem occurred/occurs with both stats.
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Here is a little vid if me showing the boiler with the problem, and how the heating starts working when I turn it off and on again.

Any ideas as to what the problem is likely to be?

 

[ianmcd]

That catches a lot of people out, myself included, most boilers when there is a demand for heating (radiator light) then the burner lights (flame light) but your boiler doesnt there is a delay before ignition , this is controlled by the boiler PCB you cant over ride it

 

[zak20vt]

Thanks for that. So I wonder if the PCB is at fault, because the boiler will stay in that state (radiator light on, but no flame light), and heating will not kick in even after 3/4 hours while the room thermostat is calling for heat.

As soon as I switch the boiler off and back on, both radiator light and flame light will come on and the boiler will fire up.

 

[bazdaman]

I have swapped a pcb for this fault

 

[zak20vt]

I have swapped a pcb for this fault

Is there any way to confirm it's the PCB or is it a case of swapping it out to see if it resolves?

 

[ianmcd]

shouldnt take that long but have seen 10-15 mins if the power has been interrupted, shouldnt take that long though, the PCB is not cheap so I would suggest a Baxi fixed price repair and it will definately be sorted , rather thn keep buying different parts and hoping they sort your problem

 

[zak20vt]

What kind of cost is a Baxi fixed price repair?

I think the PCB will be around £140:

https://www.heatingspares247.com/baxi-combi-40-printed-circuit-board-pcb-5122287.html