Baxi 105e fault on hot water sensor

[Briner2k]

The problem what I have is the neon 70 light is flashing and reading the manual it says fault on hot water sensor, this problem came up a few week ago but somehow fixed itself. I can only get HW when I put the demand for CH on.

Anyone got any pointers?

cheers

 

[hertsboilers]

If you are okay with DIY, boiler case off, isolate cold water in, drain off bit water, and replace a sensor.

Make you know which is COLD WATER INLET otherwise you will kill your boiler!

 

[Briner2k]

I have checked the sensor and that's ok I proved this by swapping the wiring on the HW (green wires) and putting it on the CH sensor and it was still flashing 70 and when I put the wires from CH to the HW sensor the light was out. I have checked for continuity in the HW wiring and that's ok. Do you think it's worth changing the PCB board?

 

[Hot&Cold]

Do you think it's worth changing the PCB board?

No

 

[Briner2k]

what do you think would be causing it to flash on fault on HW sensor if the sensor seems fine? when the demand for HW is put on the diaphragm is fine as the plunger hits the microswitch but have noticed that the diverter plunger moves up and down like it wants to fire the boiler up but think that fault light is causing it not to fire up. The HW works fine when the CH is on.