Procombi ct25 gurgling noise leading to boiler tripping out.

[Wtfalconer]

Hi first post here,

I have a procombi ct25 boiler which has just started to fail on me. The last day it started to make a noise akin to constant boiling water. This is not the usual noise leading me to suspect that a component has failed or air has somehow got into the system. I tried bleeding the heat exchanger on top of the boiler with no joy and also tried to bleed the tallest radiator with no success.

Does anyone have any clues on a potential solution regarding length of time to bleed, whether the boiler should be on doing it to force the air through or whether there is a genuine part fault.

Cheers in advance

 

[chantelle]

Sounds like `kettling` boiling like a kettle,could be scaled up heat exchanger,not enough water passing thru and causing boiler to overheat,then shutting down.Not a heating engineer. Usually probs with hot water supply also, runs too hot then cold,hot again,dodgy flow.

 

[Wtfalconer]

Kettling I like that yes it's doing that. Water flow is fine for both hot and cold same as it was before this noise. Don't believe it is scaling as water is quite soft up here though could be wrong.

 

[chantelle]

Yeah you`re wrong,it`s heat exchanger Descale is pretty straightforward, not for you though.. Fitted a black sink in soft water area, 6 weeks on it`s white with limescale..

 

[muggles]

Are you saying you're not getting anything out when you try to bleed the radiators, either water or air? If so then you may have a blocked cold feed, or the tank in your loft may have run out of water if your ball valve is stuck shut.

 

[Wtfalconer]

I get water out when I open bleed valves. Flow is no different than before though.

 

[oilhead]

Faulty boiler thermostat?

 

[chantelle]

Are you saying you're not getting anything out when you try to bleed the radiators, either water or air? If so then you may have a blocked cold feed, or the tank in your loft may have run out of water if your ball valve is stuck shut.

It hasn`t got a tank in the loft,or cold feed other than mains in/hot water out,that`s why it`s called a combi.

 

[chantelle]

Faulty boiler thermostat?

Boiler is kettling and shutting off so it is overheating,if it was boiler stat, I wouldn`t expect any noise from the boiler it would simply fire up then shut down.If you are getting heating/hot water o.k then the heated water is not getting out of the boiler fast enough causing to overheat and shutdown. Sounds like scale.But as I say I`m not engineer.

 

[Gas2Air]

Faulty boiler thermostat?

Boiler is kettling and shutting off so it is overheating,if it was boiler stat, I wouldn`t expect any noise from the boiler it would simply fire up then shut down.If you are getting heating/hot water o.k then the heated water is not getting out of the boiler fast enough causing to overheat and shutdown. Sounds like scale.But as I say I`m not engineer.

Then what are you?

 

[Wtfalconer]

If it was something to do with scale build up in the heat exchanger would I not be seeing a reduced flow of hot water which I am not getting.

 

[chantelle]

If it was something to do with scale build up in the heat exchanger would I not be seeing a reduced flow of hot water which I am not getting.

Not always,sometimes the hot water will run hot and cold or hot flow rate may be reduced, but these are some of the symptoms you may experience, just because this aint happening doesn`t mean it`s not scaled,a definite symptom is kettling/or blockage in heat exchanger.

 

[chantelle]

Then what are you

Just a poster offering some friendly advice. Why?

 

[oilhead]

If the boiler stat is not cutting off, you get exactly the symptoms you have.

 

[chantelle]

Check the temp setting on boiler if it is on max turn it down with hot water running if as soon as you lower temp the boiler cuts out it sounds like heat exchanger because it will only run on higher temp. That will rule out exchanger.