Thorne Apollo 30/50b

[gog1965]

Help.
Yesterday my boiler shut down. I was in the room when it happened. Radiators were extremely hot. I reset and same thing happened (shut down was proceeded by clanging and banging). Possibly 5 years ago the
exact same thing happened. It was the HI stat that was faulty. Today I opened the boiler and changed both HI and LO stats. I also changed the TC while it was all opened.
Now the boiler continues to run when there is no demand from the programmer? Switching the thermostat to OFF has no effect.

What have I done?

 

[Agile]

Obviously you were working beyond your skill level !

I dont know what you have done but since gas safety aspects were involved I would advise you have it checked by a competent CORGI.

The original fault sounded more like a reduced flow rate perhaps caused by a faulty pump or blockage. Whatever it was it seems as if you have added some more faults!

Tony

 

[gog1965]

Thanks Tony. I Just wanted some heat for the kids before Feb pay. (Remember Christmas!!). As for my skill level... I changed 2 stats with 2 wires each and a TC.
I was hoping for something constructive!
I had bled all radiators and all other points on system. I have checked pump is working and my 3 way valve is working ok. Then header tank is full and ballcock is working.
The system is working now but with the problems I mentioned in my 1st post.
Changing 2 stats will hardly have caused this?. I am guilty of not diagnosing fault correctly!

 

[Agile]

I think you mean something has now improved.

Can you explain what the remaining fault is?

Tony

 

[GasAid]

I'm not sure how a thermocouple could ever keep a boiler "on" as is a safety device which fails to safe... But heck - Magic does happen I suppose

Anyway - Check the wiring to the switch...

Should be Yellow piggy backed onto Yellow (At top), then brown, then white (At bottom).




Have you got the inbuilt Myson programmer or an external clock powering this? As there has to be some way-laid voltage somewhere.

 

[gog1965]

Thanks ..I have already checked the switch and it's all ok...Lo stat (with white dot) has 1 yellow and 1 white wire...HI stat (brown dot) has 1 yellow and 1 brown wire.
Nothing else has changed ... other than what's causing the fault.
I was hoping someone may have experienced the same problem in the past.

 

[Agile]

I doubt that there are many faults that I have not come across as I do boiler repairs professionally.

However I still dont know what your current boiler fault condition is.

Tony

 

[garethgas]

when you say that the boiler continues to run, do you mean its actually firing or is it just the pump over running? If its just the pump thats running and the boiler isn't firing, it should stop after 5 10 or even 15 mins or so.

 

[pannierstan]

If the boiler fires and then goes off with banging and clanging then I would check the pump overrun stat.
I have had many occasions when it either just stops after 20mins even though there is still a demand or it doesnt overrun when the heating goes off.

Round disc thing at bottom right hand back corner of combustion chamber.

Check it with the timer off and hold a match under it. You should hear the pump start.

Stan

 

[gog1965]

Thanks all: Finding it hard to find a professional in area to deal with this. Heating and water working ok but:
1: When there is no demand from programmer it continues to fire
2: Moving hi/low/off switch on boiler TS has no effect.
3:Adjusting room or tank stat has no effect.
4: When there is no demand from programmer pump stops running and you get a lot of clanging and banging and eventually safety device cuts in and gas is cut off.

At present when i need heat or water i fire up boiler and leave programmer on constant. When not in use i switch off completly and turn off gas at boiler inlet.

 

[GasAid]

Are you sure no other wires have been disconnected, played with or altered? Was this fault present before you changed the hi/lo stats?

 

[gog1965]

Not sure. Boiler went off as previously described. I refired boiler and the same thing happened. I PRESUMED it was the same fault I had 5 odd years ago (similar happened).
As far as I can see nothing else has been disturbed.

I Suspect it was a different fault and I added 2+2 and got 5.

 

[gog1965]

Sorted.
Faulty Gas Valve. £49.99 + £40 fitting.
Good as new..thanks for your help!