Help diagnosing baxi duo-tec 40

[adamharrison]

I am working on a baxi duo-tec 40 boiler there is no heating and hot water running fine. I've checked diverter valve and both motor and pin are operational.
This boiler is just over 4 yr old only serviced once before though. Next i want to check temperature sensor for central heating as they usually last around 3 years the question is Can i plug in new sensor outside of the housing while leaving broken one installed to see if it sparks and runs or would this throw an error on the display?

 

[ShaunCorbs]

You can plug it in while the other is still in the brass block but is your temp display correct ?

 

[adamharrison]

You can plug it in while the other is still in the brass block but is your temp display correct ?

Hi, I have looked into this in boiler specs and actually the sensor fault wouldn't stop the fire from going on and rather cause overheating. The temp showing around 16 which is normal when cold, the thermostat calls for heat then heating led flashes once at start then again shortly afterwards. Fan is working along with pump then goes off. I suspect pcb fault possible? have i missed anything? Also I have cleaned the filter and filled with new inhibitor just to cover all the basics still no joy. I have also tried tried starting it off from calibration mode setting max heat - same thing, fans, pump couple of mins shut off.

 

[cjg]

flow switch?

 

[adamharrison]

flow switch?

 

[adamharrison]

Now fixed, I have checked the gas valve socket and pcb no current on circuit. replaced pcb. All working now. Pretty rubbish tbh for a 4yr old boiler. Shame they skipped services as this would of been easy warranty fix.

 

[cjg]

True, but it happens a lot.