Flexicom moved

[Riley]

Morning chaps

friend of mine asked me to move his boiler into his loft, which I did yesterday. Boiler was working fine but is now making a horrendous groaning noise on DHW.

Cannot fathom it. Flexicom 30cx, three years old, serviced annually has literally just moved up and slightly offset to the left by about 2 meters. It's not air

any ideas. The only thing I wasn't involved in was taking the boiler off the wall which my mate did and yes I have ticked him off for it.

Any thoughts would be appreciated

 

[Ch4 plumbing]

Any chance its water hammer?

 

[Last Plumber]

When is it groaning ?
All the time or just when there's a flame ?

 

[Riley]

Only when there is a flame but as I say only on hot water central heating as quiet as you like

 

[Last Plumber]

It might be running at a higher gas rate on DHW. Some Vaillant boilers do that. Have you checked combustion?

 

[Riley]

Nigh on spot on 9.3%

 

[Last Plumber]

And it didn't do it before ?
Bit weird.
If it's same thing as I'm thinking, or like I've heard, ( trombone noise that fades away)
It's to do with air and combustion but never got to bottom of it. Neither did Vaillant.

Years ago they drilled an 8 mm hole in that black plastic air intake inside because a lot of Eco tec did it when it was new model. And it stopped

I don't think I'm helping here !

 

[Riley]

And it didn't do it before ?
Bit weird.
If it's same thing as I'm thinking, or like I've heard, ( trombone noise that fades away)
It's to do with air and combustion but never got to bottom of it. Neither did Vaillant.

Years ago they drilled an 8 mm hole in that black plastic air intake inside because a lot of Eco tec did it when it was new model. And it stopped

I don't think I'm helping here !

No buddy thank you I appreciate your ideas. It is doing that exact trombone noise you're making reference to i've come across it before and obviously altered the combustion and it's been fine but this one it just doesn't seem to affect

 

[Last Plumber]

I can't remember if they have the black air intake tube inside but if it has have you run it without that fitted to see if it stops

 

[quality]

Possibly a flue seal not as it should be

 

[Last Plumber]

Possibly a flue seal not as it should be

Could be !
That would effect air flow through chamber

 

[mfgs]

Its normally combustion which causes the noises on these. Checking the flue seals is a good shout, although if they were damaged/not sealing the ratio would be out. Whats the working pressure at the boiler?

 

[Riley]

That I don't know I gotta pop back

 

[Riley]

Working pressure is spot on. I'm wondering if the throttle isn't playing ball. It just won't adjust

 

[mfgs]

Working pressure is spot on. I'm wondering if the throttle isn't playing ball. It just won't adjust

Sounds like you may have found your problem, might be worth a call to Glowworm Technical before changing anything in case they have any other suggestions. That would make sense though.

 

[Riley]

Indeed. Thanks all

 

[Riley]

FYI if anyone else has this problem. Gas valve was shot purring like a kitten now. I reckon it must've been damaged when mate took it off the wall