Myson/Apollo problem

[under pressure]

Hi everybody,

I have a problem my boiler will not fire up.

I have a pilot light but when I run the hot water or turn the stat up the boiler does not fire up like it should. My house is only 18 years old so I assume the boiler has been there since it was built.

I have had this a couple of times in the past but normally if I turn it off then on again it fires up fine.

I can hear the fan running when it is on (well it sounds a bit like a fan anyway)

Any extremely helpful person got any idea ?

Alan

 

[cross thread]

gas valve jammed , it thinks the pilot has gone out but has not failed to saftey , is my guess.

 

[under pressure]

Is it easy to fit a new one ? Can I hit it with a hammer to loosen it
Is it a job I can do my self ? I am an electrician not a boiler engineer. Lastly is it expensive ?

 

[cross thread]

try pushing it in and out and slide it till the pilot goes out then relight

 

[under pressure]

I actually did this yesterday, more bby accident than design and again the pilot relit ok but the boiler did not fire up I will go and do this again now.

Thanks for your help

 

[under pressure]

No joy I am afraid. I even went as far as closing it right down. I can hear the fan stop when the mains are turned off. Pilot relights fine but it wont kick up.

I suppose now I have the job of finding a heating engineer on a Saturday afternoon, that will be easy of course

 

[namsag]

Could be a few things on this (permenant pilot )model the fan has a little pcb that contols the speed it goes .With just the pilot on it spins enough to clear the product from pilot ,with any demand the fan steps up to full speed operates a pressure switch and allows main gas to come on.. check for 240 at gas valve if its there it is a faulty solenoid 20 quid and no need to disturb any gas.

 

[giblets]

Which exact model Apollo have you got? I've been to some that "sounds" like the fan is running but it's not. Be warned that, on some models, the replacement fan is nearly £300.

 

[under pressure]

I have actually done a bit of testing. On the gas valve is a solenoid. This has mains voltage at it but when connected or disconnected the solenoid appears to be open circuit.

I assume this solenoid opens the gas valve (I am a sparks not a boiler man)

The solenoid turns on the shaft but I am not sure how to remove it any clue.

The boiler is a Myson Apollo 30/50B GC number 41 789 54 and I may be a sparks but I know a lot more about boilers than I did this morning

 

[namsag]

Right if you are getting 240v at solenoid when eveything calling and it should be on....it is held in place by the L shaped clip which just pops out with a screw driver. get part number from www.partsarena.com/baxi. open up myson page then boiler identity. part will take 2 mins to fit and no need for gas or pressure checks it does not alter anything

 

[under pressure]

Thanks for your help, I cannot find a clip to get this solenoid off and I tried to attach a picture but failed miserably. Any suggestions.

I also went to the site you suggested and I went through the parts list for this boiler and can only find the number for a gas valve. Is there a chance I may have to buy the whole thing or will the solenoid come seperately.

Also as I found a wiring diagram earlier I noticed that the wiring for this solenoid did not go through any form of circuit board so I put a 60 watt bulb across it. This lit at full brightness so I do have full voltage there.

 

[namsag]

Is the solenoid a cylinder one about inch diameter and inch in length and moves a little if you twist it .

 

[under pressure]

The solenoid is about inch and a half long and just over an inch across. It can be spun 360 degrees if the wiring is disconnected. The coil actually sits in a U shaped metal case and the centre shaft goes through each end of the U shape. Shame I cant seem to attach a picture.

When I search the GC number on parts arena (the site that you sent me) the pictures of the gas valve on there do not look anything like the solenoid I have and the parts list does not list a solenoid.

 

[ChrisR]

It alarms me a bit that a sparky has to use a light bulb to look for mains voltage!!

Most mains gas valve solenoids are a few thousand ohms, so if yours is open , it's dud.

 

[under pressure]

Chris R

The test light yes drastic I know but I was not 100% sure on my avo so after checking that it did not go thru any pcb boards I checked it with a bulb. I had already put the avo across the solenoid, no circuit at all and I had already put an amp meter in line to see if there was any load, there was not.

The bulb was really just proving to me that my avo was reading correctly as it had a funny ten minutes lol