Pilot light won't light on Myson Apollo 50B Gas burner

[Mike Mac C]

Hi All.
I would really appreciate any information anyone can give regarding re-igniting a Myson Apollo 50 B Central Heating gas burner
I’ve tried depressing the gas valve operating button and then pressing the ignition but although the pilot will light when the gas valve is depressed it will not stay lighting when you take your thumb off the gas valve, no matter how slowly I let go. Ive also tried pushing the button in the direction of the arrow and re trying after 3 minutes as suggested on the instructions but to no avail.

I’ve tried this repeatedly for the last hour but to no avail. Needless to say its our only form of heating and to top it all its absolutely freezing here and there is no hope of a repairman coming until the New Year!!!!!.

 

[JohnD]

I think it will be the thermocouple.

This is a small electrical device that sits in the pilot light flame. when the pilot is alight the thermocouple detects the heat and switches the gas on. If the pilot goes out the thermocouple detects that there is no heat and turns the gas off (it is connected to an electrically operated gas tap).

When you first light the boiler, you have to press and hold the start button, that overrides the thermocouple so that you can get enough gas to light the pilot. Once the thermocouple is hot you can release the button.

Every two or three years the thermocouple burns out and you have to fit a new one. It is held in place by a screwed brass collar with a slit in it to fit over the copper tube that comes out of the end of the thermocouple.

I'm actually sitting looking at one now that was replaced today.

you can buy a universal thermocouple in any heating/plumbing merchant and larger DIY sheds, but to fit it you need to be competent to work with electrical and gas devices, so you ought to get a competent pro to fit it.

 

[Slogger]

ah but no but

seems he can do it himself if he is the owner of the house and isnt subletting

shame on corgi

 

[JohnD]

he's in Ireland anyway, but I have no way of knowing if he can do it properly. It's a bit fiddly, especially if you've never done one before and have no instruction manual.

Maybe phone a few, say you need a new thermocouple fitting (less than an hour's work) and see who knows the job and is willing?

 

[JohnD]

Naughty boy, you asked this twice.

//www.diynot.com/forums/viewtopic.php?t=39148

 

[Mike Mac C]

Naughty boy, you asked this twice.

//www.diynot.com/forums/viewtopic.php?t=39148

I did indeed post it twice, but, out of utter nervous desperation rather than any intended naughtiness on my behalf . Im to get a TC from a local supplier tomorrow and i will fit it tomorrow night! If you dont hear from me again, you will know I made a hash of it!!!!! ...
I will not have need of any heat in the place I end up!!!!!

In the interim... many thanks to all of you for your help and have a happy ( and warm ) christmas!!!

Regards
Mike

 

[JohnD]

Get a spare for next time.

Good luck!

 

[Mike Mac C]

Guys!!!
what can I say!!! Thermo coupled... tis like Hawaii in thge hallways,,,, Bermuda in the Bedrooms.. thanks to my( Yes me personally!!!!!) fitting a TC in the boiler. Im so glad now i turned down the guy who offered to come out on saturday for €200 strait up and € 100 per hr after that .. Thanks a mill guys your advice was appreciated more than you will ever know.

Regardshappy Christmas and most of all
Many Many Thanks
Mike

 

[Paul Barker]

You got lucky, sometimes it's the oveheat stat sometimes a short between oh stat wiring and tc to ground, sometimes power unit in gas valve which can't usually be obtained so have to buy gas valve, some of which cost £139 plus vat trade price.

Don't go thinking it's al;ways a change of tc to fix a simple boiler like that.

temp stats are probably in a right old state wiring is probably crusty and ready to break down, heat ex probably needs a good clean and burner. main jet, gas pressure and finally gas rating.

But hay you've go heat for now.