Noisy Combi Boiler

[SMK]

Hi

Looking for a little advise to make sure I'm not being told rubbish we’ve had some building work done and the bathroom moved and additional radiators fitted, and the Flue moved. I trust my plumber but its find its always good to have a little knowledge when dealing with him

We’ve got a Worcester 24CDI Combi Boiler when starting from Cold First bangs very loudly then appears to shut down for a couple of minutes then starts up again, bangs loudly and appears to shut down does this a couple of times and then appears to work ok. This is from both CH and DHW Once working we have hot radiators and the boiler makes no more noise than normal, but the DHW is not as good as it used to be (Think its the divertor?).

Any advice woudl be appreciated before i call in the engineer

 

[GQuigley67]

sounds like explosive ignition get it checked over by a competent gas safe engineer

 

[E4gas]

Looking for a little advise to make sure I'm not being told rubbish we’ve had some building work done and the bathroom moved and additional radiators fitted, and the Flue moved. I trust my plumber but its find its always good to have a little knowledge when dealing with him

We’ve got a Worcester 24CDI Combi Boiler when starting from Cold First bangs very loudly then appears to shut down for a couple of minutes then starts up again, bangs loudly and appears to shut down does this a couple of times and then appears to work ok. This is from both CH and DHW Once working we have hot radiators and the boiler makes no more noise than normal, but the DHW is not as good as it used to be (Think its the divertor?).

Any advice woudl be appreciated before i call in the engineer[/QUOTE]

 

[E4gas]

SMK What do mean , he moved the flue , he has to be gas safe to do this

 

[SMK]

He is (but was provided by the builders so I will check), the flue was through the wall, he moved it and extended it so its now through the Roof rather than the new bedroom

 

[SMK]

sounds like explosive ignition get it checked over by a competent gas safe engineer

There are several Loud Bangs and the Pressure pressure guage Jumps would that still be explosive ignition

 

[GQuigley67]

without seeing it i dont know but it doesn't sound healthy

 

[SMK]

Cheers GQuigley

That bit I know, what i dont is would explosive ignition be 1 loud bang or could it be several with the pressure guage jumping?

 

[Gray0689]

Cheers GQuigley

That bit I know, what i dont is would explosive ignition be 1 loud bang or could it be several with the pressure guage jumping?

It could be both
Needs checking out

 

[GQuigley67]

it could be a diverter valve problem, i had similar symptoms with my old boiler banging noises at the boiler/rads and pressure guage jumping

 

[AWheating]

could be badly installed flue causing ignition problem.(explosive ignition) this can happen when the flue is incorrect and causes a lack of air supply making a build up of gas in the combustion chamber. could possible be the inside/poc tube being disconnect somewhere due to extensions being cut to short on installation. this would make a bang every time the boiler try to fire up.

it could also be something like a diverter vavle stuck/blockage, sometimes when a boiler is drained down and left to dry out things can stick or sludge can go solid.

either way get your engineer back to take a look, leave the boiler cold for when he/she arrives

 

[SMK]

Once its lit and warmed up it seems fine, making no more noise than normal, he'll be coming back on Tuesday !!

 

[jtsplumbing]

Are you in a hard water area ?? you may have a problem with scale !

 

[SMK]

we're in Bristol so yes,

 

[E4gas]

Any photos of the flue system

 

[jtsplumbing]

Hi possable you have scale in heat exchanger this will cause knocking / banging untll boiler gets hot , may have to get a descale , has system been clean`d ? used to get lots of problems with scale when i lived in Bracknell , but now in Devon so no longer applies.

 

[SMK]

Will try and gt a pic uploaded

Cheers