Baxi 105e problem! Need help please!:)

[Ljcar]

Ok so I'm a gas engineer and went to a job today, basically the burner comes on when it's on hot water&heating for 3 seconds then goes of for 3 seconds then just repeats that cycle with no fault code.

I've tried a new pcb
I'm getting 20.9 on clean air intake
The fan sounds a bit squeaky but wouldn't affect this
I've taken a working pressure at the meter and it's come back at 17.1mb , the inlet at the boiler is 15.5mb and the max burner pressure is 12.9.

I'm pretty stuck for ideas really as there is no way of electrically fault finding this problem, national grid are increasing the pressure tonight as I've capped it overnight, I'm going back first thing so if anyone has any ideas I'd be interested to here them.

Thanks

 

[ianmcd]

Sorry but you will not get any response on here, if you are indeed a registered gas installer then you will have to register for the combustion chamber then you will get all the help for this and any future problems you have , the site rules do not permit us from replying to combustion questions on the open forum

 

[Ljcar]

Sorry but you will not get any response on here, if you are indeed a registered gas installer then you will have to register for the combustion chamber then you will get all the help for this and any future problems you have , the site rules permit us from replying to combustion questions on the open forum

how do I get it there?nvm found it thanks