Baxi 105e

[DP]

I fitted above boiler some 5 years ago as an S plan with boiler delivering HW to kitchen sink.

The house was later extended with extention floor underheated (installed by the builder) on third MV.

Boiler soon started to act up. But this malfunction was due to PCB problem (fan not runnung). There were issues with underfloor heating control connections

Now the boiler is locking out on flame failure. It is very random never doing this when I am there. Ignition BP is 3mb. Could overheat cause this led to light up as well?

 

[Agile]

A very common problem is the minimum gas pressure is too low and it loses flame detection. But you would have checked that wouldn't you.

I have also found some considerable variations in sensivity of the flame detection as well as one where the exact placement of the detection electrode was critical within the mechanical variables.

Tony

 

[DP]

Take it there is no more feedback to aforementioned problem.

 

[namsag]

If it was the over heat stat tripping it then the second neon would also be lit.. The minimum pressure is 2.5mb +/- 0.2 . so 3 isn`t far out . Does it do it first thing in the morning ,possible meter govenor sticking over night with no demand. Or could be a faulty board again had a couple where it wa just once in a while then got worse

 

[baxpoti]

You have checked flame rectification? 0.5vdc ?

Check the wiring on the Honeywell igniter is correct as follows...

Earth on top
Live in the middle
Neutral on the bottom


Check the venturi is not deformed or partially blocked.

 

[DP]

Thanks for replying. Will check and post findings.