Main Combi 30HE Fan / Flue fault.

[MrLeeroyBrown]

Hello, I Wonder if anyone can help - got an issue with my Main Combi 30HE & it is confusing me a lot!! (doesn't take much 🙂

Problem is with firing up - the diagnostic reports the issue is either the fan or the flue.

I 'can' get it to fire up, but usually only on the 10-15th time of trying & only when the front of the unit has been taken off.

Once fired up, (I replace the front!), I have had it operate anywhere between 1 minute & 6 hours before it shuts down with the fault again.

On checking, I can't see any blockage in the flue outside & the fan seems to be operating fine & at a decent speed.

I've took the spigot off the fan manifold & peered inside the fan and eveything seems as it should.

I've checked the air pressure switch & the sensing tubes and they seem ok too - i.e. when I blow into them I can hear the microswitches operating & there doesn't appear to be a blockage / break in the tubes.

I pretty convinced something is causing the air pressure switch to trip, though can't work out what??

A couple of times when I have managed to fire it up, i have noticed the air flow seems to be coming in waves - almost as if there is some sort of backdraft. Could it be possible wind is coming back in through the flue?

The confusing part is the problem only seems to have started since the cold weather set in?

Has anyone got any thoughts on what the problem might be?

Thanks
Lee.

 

[plumbbobshan]

Hello Mr , Have you tried cleaning the small venturi that the air pipe is attached to in the flue . I have had a cobweb over this and it stopped it working . Strange but true .

 

[MrLeeroyBrown]

Hi PlumBob, thanks for the reply. Not tried it, will have a look - it's got to be something around that area. Thanks!

Lee.

 

[wnjswozo]

replace aps,commen fault

 

[MrLeeroyBrown]

After cleaning everything up, & removing the fan & the APS & putting back together - still got the same issue.

As wnjswozo says above, think the APS has developed a fault, even though the microswitches are still operating - gonna replace it.

Thanks all for the advice.

Let you know if this resolves the issue.

Now... where to get one?

 

[REDSAW]

please refer to the gas fitter forum.

 

[Poxi]

You say you can get it to run with the combustion chamber door off..I strongly advise you get a GAS SAFE engineer in pronto and check your flue joints...If OK Then yes, Continuity check APS

 

[MrLeeroyBrown]

No, not that stupid!...but appreciated 🙂

The front of the unit meaning the sound proofing!? Not sure what u call it, not the combustion chamber front...

 

[SafeGasInstall]

must not play with it !!!! you put your self and other at potential DANGER !!!!

 

[Puddle]

Think this should help you out Lee

http://www.User PlumbersForums.net Instead - Copy the content, don't link to it.co.uk/

Removing flue parts and boiler casings is a very dangerous thing to do,when doing up your home,you are going to have to distinguish between the jobs that are safe to do and those that are best left to a fully trained person,this is a job for a trained gas plumber,that way all has a chance of running smoothly and you may stay healthy !

 

[MrLeeroyBrown]

Ok thanks, I appreciate the advice & it is a reality check. For the peace of mind of everyone i've not gone near the gas valve or burner or anything such like... most i have done is take the front of the combustion chamber off to get at the fan - everything has been replaced in methodical order. But now, yes - i'll get an engineer out to do the work (confidence down 1 notch) - just didn't want to get stiffed by an hour of fault finding......

 

[SafeGasInstall]

God help your engineer !!!


It will cost you more now!

 

[MrLeeroyBrown]

Replaced APS, now working fine.