Apollo 40 Banging and cutting out

[Martin78]

Hello - I hope someone can help me with my boiler problem:

- It's a standard gas boiler - Myson Apollo 40. Probably about 19 years old.

- The problem is that the boiler is firing up when on timer and working well for about 20mins but then it starts banging and clanking, all the way up from the boiler unit on the kitchen wall, through the radiators and heat exchanger (?) in the airing cupboard up to water storage tank (?) in the loft where there is a small splashing sound as the noise (air?) finishes it's journey. (You can probably tell I'm not an expert so apologies if I'm getting the names of things wrong!) When this happens the flame just goes back to the pilot light setting. When it fires up again a few minutes later it works fine for about 15secs and then the banging starts and it cuts out. Same again, and again and again with the effect being that the radiators start to go cold. It's fair to say that I don't need an alarm clock in the morning anymore! I've found that if we knock the power off to the unit and leave it for a while to give it a rest, when it comes back on it works great for 20mins and then the noisy cycle starts again.

- I got an engineer out and they said that the pump was quite new so they didn't think it would be that so they changed the "pump over stat" as they said they they thought it was overheating and the flame was cutting out automatically due to a safety mechanism. As it turns out, the part that they changed wasn't scorched as they had expected but they said it might be "an intermittent fault" so they changed it anyway. This made absoulutely no difference. I called them to tell them this and they said it might be the pump but they wouldn't know till they changed it (more expense and no guarantees that it would work). Or there could be dirt in the system but apparently it would cost a fortune to flush it out. I asked them if it could be the wiring but they didn't think so. He rounded off by saying that I should probably just leave it till it packs in completely and then it would be obvious what it was - or just get a new boiler as it is quite old! We've stretched ourselves by moving into a bigger house and will have to borrow money for a new one so I don't want to unless it's absolutely necessary. I was a bit disappointed that I was out of pocket and was still no further forward but to be fair the engineer still gave his time and a new part so it's just bad luck I suppose.

I think I will be getting someone else out (pot luck in the yellow pages) but I thought I'd ask tall you experts on here if you have got any ideas first so that I can make suggestions if the new engineer says the same as the last one.

I think I have probably put too much information on here but if anyone is still awake - thanks for getting this far and I'd really appreciate any advice that you can give.

Thanks

Martin

 

[pannierstan]

In actual fact Martin it sounds like you have found a gem of an engineer there so try to move away dissing him

I would have done the same thing from your explanation an too often plumbers jump in and charge a fortune to change the pump when it is actually the pump over run stat so I take my hat off to him.

You have been unlucky, but why wont you get him back to do the pump? or do you just presume that he is not up to the job.

He sounds striaght up so why dont you do your self a favour and get hm to change the pump. In these circumstances I usually ask the customer to give it a try for a few days leaving the old pump on site and if it doesnt sort it then refit the old one, but you will still have to pay some labour!!

TBH its one or the other with that boiler.

Stan

 

[Martin78]

Thanks for this Stan.

The reason I was going to go elsewhere was just that when I spoke to him he didn't seem confident about it being the pump so I thought I'd get a 2nd opinon - maybe I just picked him up wrong.

I appreciate the insight about him not changing the pump first when he could and I would have been none the wiser so cheers for that. Didn't mean it to come across as having a pop at him - just the thing about getting a new boiler seemed a bit simplistic (and expensive!).

I think I'll take your advice and get him back out. Hopefully the new pump will fix it for now and I'll start saving for a new boiler cos as he said, it is quite old for a boiler.

Thanks again.

Martin

 

[namsag]

Your bolier has a thermostat switch that says high and low , does it bang on both of these position

 

[Martin78]

Hello Namsag.

The system bangs when the thermostat switch is on both high and low.
I can check if the banging is particularly worse on one position if that would help?

One thing I forgot to mention earlier was to ask how similar the Apollo 30 is to the Apollo 40?

The reason I ask is that I noticed a post on here from 2005 in relation to someone that had an Apollo 30 that was having what sounded like a similar problem to my 40 and it turned out that the cold feed to the pump was blocked so the pump had burnt out. Could this be an option for mine or would it be something that the engineer would have checked at the outset?

Thanks

Martin

 

[pannierstan]

Again Martin it could well be a blockage but would be unusual that everything worked for 20 mins. If the cold feed was blocked and the systems got no head then usually you wont get anything but banging from the outset.

If he comes to change the pump ask him to check for a blocked cold feed. When he takes the pump out have a look at the ports. They will tell you what state the internals of your system are in.
Ask him what configuration of cold feed and expansion you have. If he says its an H config and there is **** in there get it altered to an Airjec or something.

Like I said before he seems like a good un. Have some faith old fruit.

Stan

 

[gas4you]

If you bleed the rads upstairs do you get air and water out, or nothing?

 

[Martin78]

Hello Dave.

When I bled the radiators I got air and then water out of them or just water straight away - they all did something. Didn't make any difference to the banging unfortunately.

Thanks

Martin

 

[gas4you]

Didn't expect that it would, I was just trying to establish whether you had a cold fill blockage or not. For now we'll assume not!

 

[Martin78]

Sorry Stan - forgot to reply to yours!

Thanks for the extra info - If he doesn't mention anything about the things you mentioned I'll ask him just incase.

I didn't get the chance to ring the engineer today but I'll be doing it ASAP.

Thanks again for your help - it's much appreciated.

Martin

 

[Martin78]

Thanks for this Dave - maybe not the cold fill then eh?

Cheers for the info - much appreciated.

Martin