Loud Noise from Combi-Boiler

[Asurya]

Hi All.

My family and I have been settled in our new house for a little over 6 months now and this particular 'event' has happened 3 times now. I say event, as I'm uncertain if it's a problem or not.

Basically, in the last 6 months, 3 times our boiler has started to emit a very loud buzzing noise when the CH is on, we've never heard it during DHW. The last time was a few months ago, and the latest time was at 4am last night, and again earlier this morning. As I said, this is loud enough to wake my wife and I up.

I have noticed that a) as soon as I turn the CH off at the timer, the noise stops and b) upon inspection of the boiler itself, the pressure gauge is just over the recomendded 1.5 bar.

Leaving the CH off for a while seems to be allowing the pressure to reduce itself back under the 1.5 bar.

Like I said, this has only happended about 3-4 times in the last 6 months, and not knowing the ins and outs of even the most basic plumbing systems, for all I know this is normal.

Can anyone advise.

Thanks in adavnce.

 

[Breesey]

What boiler is it etc etc?

How far under 1.5 bar?

 

[ChrisR]

Boiler is...?

 

[Asurya]

Opps, I orginally put it in the subject line, but removed it.

The boiler is a Linea 24 and when the pressure returns under the 1.5 it stops about 1.3~1.4, which is within the recomended range.

Anyways, cheers for the replies so far.

 

[Breesey]

Is the noise definitly coming from the boiler?
When was it last serviced?
Does the heating work OK? ie it heats the rads and keeps them hot with out short cycling
Maybe something gets lodged in the main heat exchanger and vibrates!

The pressure will increase with temp increase. This is normal, and over pressurisation is protected by a pressure relief valve that will relieve at about 3 bar. Have you had to top up the system at all?

 

[bones001]

could be the solenoid on the gas valve

 

[Asurya]

Thanks for the responses.

Yeah, everything works OK with regard to heating and hot water, but we've never had to top up the system.

I don't know about serviced, but it was certainly checked over at the start of October when the British Gas Engineer was out to do an inspection after taking out their boiler protection. He said at the time, that although it was an older model, it was a good boiler and in perfect working condition.

I guess I was really just worried out the pressure increase, but I suppose I should have remembered Boyle's Law huh?

Anyways, my wife called the BG Homecare line and an engineer is going to have a look tomorrow, so hopefully he'll find the fault (if any).

Cheers again.

 

[gas4you]

I've had a couple of these that had really noisey gas valve solenoids as well.