Baxi 105 flue/fan fault

[DerekJ]

Hi Guys,

I have a Baxi 105e that's not firing up, can any one here help with the diagnostics?

Here is what happens...

I reset the boiler (just in case) and draw hot water. The water priority valve flips over and activates the microswitch then the boiler tries to start.

The fan kicks in and spins freely, the APS switch clicks immediately but then the fan powers down after about a second. This cycle continues for about five times before the Fan/Flue lamp starts to flash.

If I leave it for a while longer, the fan stays on and the ignition sequence completes. Once running it stays on until the water is turned off.

If the water is turned off before the boiler lights the fault lamp stops flashing and goes out. The system does NOT lock out until reset and will try to restart when water is drawn again.

I replaced the APS but, if anything, it takes longer to light.

The pressure sense tubes looked OK but I replaced them anyway.

Do I change the main board or is there something else I'm missing??

Thanks
DerekJ

 

[Agile]

Accessing the fan and APS should only be done by someone who is gas registered.

Faults like that are often caused by the PCB if everything else is working correctly.

Recently I went to one which was giving similar problems and it turned out to be the temperature sensor.

Tony

 

[Gasman77]

Are you an RGI Derek?