Vaillant Sine 18 no CH

[Tintin007]

Thought it might be - have vented it and swapped the valves over but am no further forward....

No HW or CH - main burner not lighting at all. Can hear various clicks that normally precede the main burner lighting but no main burner !

Have pressed the black over-ride but no change and have also lit and relit the pilot light - still no change......

 

[The831Bunny]

Hopefully you're competent to work on gas appliances OP, because the combustion chamber and sometimes the burner needs removing to fully remove the Flow Switch. Most 'engineers' also don't know how to refit the combustion chamber correctly either, leading to CO leaks into the room.

Waterside components are fine to work on, but removing the chamber cover is for Gas Safe registered engineers only I'm afraid. Those are the rules.

 

[Tintin007]

Well - have vented some air out of the system and relit the pilot and now the main burners are firing up fine. Did not do anything else so another Sine 18 that does not work after relighting the pilot.

Replacement flowswitch working and the spindle rising at the back of the valve (never dis that before) and bottom half just as hot as the top when heating on.

Still not fixed though as the pressure is building up too quickly (after about 10 mins running it is over 2 bar from just below 0.5 bar cold). DHW temperature seems very much hotter than before. Stat is set at 2 and temperature showing around 60 C.

House is a lot warmer though.....

 

[Bunnyman]

As 831 said I hope to Fook for u have got that black combustion front on, they are a pig an many get em wrong, co is a silent killer hence no gas advice on here

 

[Tintin007]

Black combustion cover back on properly !

Have discovered what the problem is - although the temp gauge sits at 60C when the boiler is running it is telling fibs - I put the probe into a cup of boiling water straight from the kettle and it reads 75C !

Does this mean the main PCB is faulty or is it likely to be the probe itself ?

 

[Agile]

You should never have opened the combustion chamber!

We dont give DIY boiler repair advice here!

Any bunny who advocates DIY repairs deserves to be culled like the badgers!

The temperature gauge is physio thermal and not connected with the PCB.

Tony

 

[DP]

physio thermal

You having a laugh tony?

 

[Agile]

Deadly Serious Danny!