Baxi 105 he - No central heating. Hot Water fine!

[niccnicc]

Hot water works fine. The central heating does not respond at all. Original link in across the CH demand terminals - no external controls.

Any ideas!?

Thanks in advance.

 

[fitz1]

is there power at the link

 

[niccnicc]

Yes, there is power at the link, boiler not old

 

[Agile]

Any lights to indicate a fault?

Does burner go off IMMEDIATELY you finish using hot water?

Tony

 

[niccnicc]

No flashing warning lights.

After using hot water, temperature lights remain constantly on to indicate temperature (steady)

Post hot water turn off, burner stops immediately, flue fan continues for approx 10 secs. Power on light on all the time. DHW light on whilst drawing; burner light on whilst burner on; all off correctly

 

[Agile]

No flashing warning lights.

I think that a fault indication is given of a failed sensor by a STEADY on light of 70° or 80°.

Normal temperature indication is, I think, ALL the temperature lights below the actual temperature.

It might still be a back contact on the DHW switch failed as I think that has to be made before CH can work.

Tony

 

[niccnicc]

Cheers Tony.

I am sure there are no fail lights. If the boiler is left long enough after drawing hot water all the lights will go out and this is with the slector requesting CH (in the CH / HW mode)

 

[namsag]

I take it you have the clock on front panel take cover off and link the two black wires at the clock if it fires its a faulty clock.

obviously turning power off first