Myson Apollo pilot light

[AnEngineer]

Hi - I have one of these and its always packed in each year or so for a pilot light thermocouple failure. Replace it and it works fine again for another year or so!

This time....its off and on ...works a few days ...then not. Mostly pilot light is still on, gas valve solenoid works fine (the sound of it kicking in) ...but no gas flow. Sometimes, with the gas valve solenoid on and pilot light is on, if I push in the pilot light gas button a few times..the boiler lights - no sound of gas valve kicking in as it is already energised, it seems the thermocouple part of the gas valve circuit is stopping the gas getting through.

I've tried turing off and on repeatedly the gas valve (via boiler hi/off/lo switch). I hear gas valve kicking in and out - no problem.

The pilot light in almost all cases is on, the main gas valve is on, but still no gas flow.

Sometimes when I push in the pilot light gas button the pilot light goes out. Normal sequence to light it again.

So...I think the gas valve part is fine. The problem seems to be to do with the electrical part of the circuit that is linked to the pilot light...i.e. the thermocouple circuit.

I do not really want to replace gas valve (unless its cheap - parts plus labour) as I wish to replace boiler in a year or so.

I have presumed that if any of the overtemp stat's were breaking the circuit they would stop the gas solenoid from kicking in and if it was the stat in series with the thermocouple - then then pilot light would go out.

Therefore - can anyone offer any advice on how to fix this.

Thanks for any help.

Kind Regards

 

[ChrisR]

It sounds very much like you don't know how it works or what you're doing. Apollo's kill people, 40 something last I heard.
Leave it alone and call a Corgi. The bill should be between £100 and £200.

 

[AnEngineer]

Thanks for the advice. I of course will call a corgi gas Engineer when I am convinced I know what the problem is. You are correct that I do not know what is causing this, hence this post, but my fault finding process of elimination is given here in the hope that someone who understands this may be able to explain what is at fault. Anyone can call an gas engineer and be at their mercy in terms of charges - I have personal experience of Gas Engineers (2 of them on separate occasions whilst the boiler failed under warranty) unable to diagnose a basic thermocouple fault - something I eventually had to take an afternoon off work and diagnose and repair myself as it was 2 days before christmas and no engineer in sight until new year.

I have many experiences in industry (I'm a Chartered Engineer) with household appliances, cars, you name it and even gas boilers where Engineers can only offer to replace complete components (due to time and maybe profit) when in fact I have traced the problem to a component that can be bought and replaced individually at minimal cost.

If in fact this requires a corgi Engineer - I'm happy to employ one - but first I wish to identify the fault - though at £100-£200 I suspect this is for a replaced gas valve and not worth it when the boiler is 17 years old and a new boiler is £400 - £700 - I can fit this - it only requires a corgi Engineer to connect it to the gas - an hour or two's work at most!

Anyhow - thanks for the obvious advice - maybe someone who does understand my post can explain what the fault is and why the gas valve may need replacing.

Not posting this to promote any argument or negative feedback - I'm not interested in "tit for tat" but I disagree with your comment that I do not know what I'm doing - I was hoping someone would recognize this process of elimination and offer advice - I just do not yet understand in detail how the internals of this gas valve works - the principal is simple - the actual component at fault a little more difficult to identify - I had hoped that a gas engineer might identify exactly what part of the gas valve is at fault and cite what a corgi engineer can do to fix this apart from simply replacing the whole valve....maybe nothing else can be done but at least I will know.

Thanks again.

Kind Regards[/b]

 

[Benny_the_ball-valve]

.....not worth it when the boiler is 17 years old and a new boiler is £400 - £700 - I can fit this - it only requires a corgi Engineer to connect it to the gas - an hour or two's work at most!

I am not a gas engineer so am unable to be of much help, but I think that you rather underestimate the ease with which you will be able to enlist a CORGI engineer to connect your new boiler to the gas supply. He is very unlikely to be prepared to sanction your installation work. There might be good reason depending on your abilities, on the other hand there are those that believe that this tactic is deployed to discourage DIY'ers. My own experience is that CORGI seem to be a pretty obstructive lot to those not inside the magic circle, but the fact remains that they hold huge legal sway ie you need them, they don't need you!

 

[AnEngineer]

Thanks for that.

I agree that many, if given the chance, will want the whole job at their price. I am prepared to pay a reasonable price for the scope of the job - but I know how difficult or easy a job is and what its worth. I've had people trying to tell me for years why its so difficult and expensive - I manage projects like this every day and always find someone who is honest and does a good job for a good price - then we are all happy. So I will find a good corgi guy and discuss this with him so that we can agree his part and a price we will both be happy with.

I tend to weigh up a job totally to know what needs to be done and decide what part I'll do, from none to the lot. Now this is a gas unit so I need a corgi engineer - but I can certainly bolt it on the wall and do all water pipe work and electrics.

I'm expecting to pay a day rate at most even if it only takes the corgi guy 2 hours - that's not unusual - if I'm lucky I may find a recommended corgi engineer who will only charge 1/2 day or acceptable fixed price.

I will not just call anyone to do a job - some corgi guy's (as in all walks of life - so I'm not having a go at any individual trade) are simply not up to giving a good job for a good price - we have all seen this - be it your car service, shop assistant, bank - you name it.

Yes you always need someone - but only the good ones and so far in life I find that many people can be reasonable if you take the time to find them.

You always need them - but they need you too - I give good feedback when I get a good job, I also let them know when its poor - and we all tell our friends and now the web - so I hope those who are good, prosper, and those who are bad change their ways or find something they are good at.

Thanks again for your comments.

Kind Regards

 

[namsag]

1, Because you hear the solenoid clicking doesnt mean it is operating properly and opening the gas valve. 2, overheat stat does not affect the power going to the solenoid it just breaks the signal being generated from the themocouple tip to the power pack on the gas valve that it screws into. 3, because pilot is lit does not mean proper signal being received at the gas valve if the pilot button is sticking half way this will allow pilot to stay on without energising power pack in gas valve(make sure pilot button comes all way out. All really basic stuff . Without it sounding cheeky people like yourself with a limited knowledge who think they can do it themselves and people are out to rip them off are the worst customers . and no you are not allowed to fit the boiler and flue by yourself this also must be done by a corgi registered person.

 

[ChrisR]

Mr Engineer. Your problem is that you are ignorant. That is a judgement I made, and it was borne out by your subsequent comments. You simply do not know what you need to know. You clearly think that you are quite OK to change a gas valve. Or a boiler. You aren't.

I have many experiences in industry (I'm a Chartered Engineer) with household appliances, cars, you name it

So am I, and probably several others here. Makes no difference, none of it helps. In fact you should have learned to have more respect for engineers in any field, who know their subject and are trying to give you best advice.

I told you of the particular dangers of the Apollo. You'd better make sure yours isn't going to kill you tonight - simple, if you know what to look for.

 

[AnEngineer]

Thanks namsag for the feedback - no problem with "cheeky" comment - not offended - that's why I'm asking and thanks for the time to explain - a lot more use than pointless aggressive reply of ChrisR who appears to me as bitter and cynical and maybe needs to lighten up a bit if you forgive the pun!

I guess I'm a difficult customer if that means I like to know I'm getting the service I paid for and always check. I give praise when I get a good service, I complain when I do not. If I knew nothing I guess I would be non the wiser if I got a good service or not - probably just poorer.

I'm afraid there are too many people out there who are trying to rip us all off - so buyer beware. Currently I'm waiting for my car dealer to get a part (engine cover) they damaged during a service, then they gave me the car back with no mention of it or evidence of ordering a replacement and they think that's ok - well not in my book. So should I trust everyone - even the service manager who smiles as he hands me my key and takes my money - would you? - only a poorer man would - so sorry - I know there are many people of all walks of life are out to take your money but maybe not deliver the desired service. The good ones are gems and I keep their contact details and recommend them.

No big deal - just my approach - anyone else can decide what's best for them - who am I to criticize - its their money!

Anyhow - I've fixed it! - thanks for all the advice ...by the way it was non of the points mentioned but I really do appreciate the good advice...a simple process of elimination identified the problem and I've saved myself £100-£200 if ChrisR was correct in citing this charge for a "simple if you know what to look for" service.

Kind Regards

 

[kevplumb]

you call yourself what you like bonny lad (geordie ) you get good advice on this site and tho me and chris dont always agree (and i'm sure a few others ) you havent a clue how that boiler works and what safety devices are built in to it you had a lucky guess

but then again what the h*ll do i know i've only been repairing the things from new

 

[ChrisR]

"simple if you know what to look for"
appllied to the Apollo feature which might kill you. Of which you are evidently, still, blissfully ignorant.
Now that you've been pratting about with your boiler it probably leaks gas as well, or will soon.

 

[kevplumb]

to quote yourself mate "dont spoil my fun "

 

[ChrisR]

You want him DEAD? I only wanted the other guy WET!

 

[croydoncorgi]

Just to clarify most CORGI's reaction to requests to'just connect the boiler to the gas'. In most cases - 'not interested'.

There is a REASON for this. It's common sense! If I take on this sort of job and then something goes wrong, I will be the fall-guy! It makes ABSOLUTELY NO DIFFERENCE whether the fault was actually my work or not. I (as a CORGI installer) was the last man in and therefore COMPLETELY responsible for gas safety for the whole system.

If you really are a chartered engineer, I'm gob-smacked that you are unaware of this priciple!

 

[namsag]

So what was up with it then?

 

[AnEngineer]

Thermocouple millivolts! - cleaned pilot hood and repositioned to direct flame to thermocouple tip & hey presto!

So I suspect, failed thermocouple first time, subsequent thermocouple(s) not quite in same position in flame or on the limit for emf and possibily dirt in the pilot hood so flame direction iffy. Anyhow - sorted!

Also dry joint on pcb!

Thanks namsag - your comments helped.