Intermittent loud buzzing from combi-boiler

[Gordonbennett]

We have a problem with a wall-mounted Ideal Classic SE18 combi-boiler installed in November 2004. About two months ago it started to make an intermittent very loud buzzing, loud enough to be heard from outside the house. which lasts anything from a few seconds to a couple of minutes. Sometimes the boiler can go for hours without doing this, and at other times the buzzing is repeated two or three times an hour. It's very sporadic and irregular, and does not seem to be related to the boiler turning itself on and off.
I wonder if anyone can explain this. Surely it must have happened elsewhere.

 

[bengasman]

Anything unusual in the working when this happens?

 

[Gordonbennett]

No. Everything works fine. We've mentioned it to the service engineer who installed it, and he doesn't know what it is exactly but considers it not to be serious, just inconvenient. He's right about that.
We're just concerned that this buzzing will get worse.

 

[Agile]

A genuine mains frequency 100 Hz buzz is sometimes produced by the gas valve.

I do however wonder if its really a buzz or instead a pipe resonance?

Tony

 

[Gordonbennett]

No this is definitely an electronic buzzing and it's loud which sounds like an alarm clock going off. We've made a tape recording of it, (but not digitally) to play back should we decide to call in a plumbing engineer, because there is no way we can make the sound occur - it just happens.

 

[Agile]

Could well be the gas valve.

BUT there is a fault on some PCBs which will make the gas valve buzz through no fault of the gas valve! That would normally be all the time or at least at the same level of power output!

Tony

 

[superdupergasman]

I have heard plenty of their gas valves buz but nothing like the volume that you are talking about....only once heard a worcester 350 make a loud buzz from the gas valve and that was from the PCB as Agile suggests.

What about the fan?? Those boilers fans are mounted on rubber bushes, horizontally which are prone to settling and then the outer impellar rubs on the casing of the fan.

 

[Gordonbennett]

We had the fan replaced earlier this year, but the noise that it had been making was nothing as bad as this and altogether different. Try and imagine something between a bedside alarm and heavy industrial machinery.

I've now made a 10-second 69kb. wav. file of the sound but can't see a way of posting it on this forum.

 

[Gordonbennett]

Could it be something to do with the solenoid? It is almost certainly an electrical fault.

 

[Gordonbennett]

Pardon my ignorance, but does the gas valve incorporate the solenoid? We are now considering replacing the valve as we can't think what else to do.

 

[Gordonbennett]

Just to update the forum on this, we have now had the gas valve replaced, and all appears well, though the engineer did indicate that the "next thing to go" may well be the PCB(!), but we are hoping that will not be for a very long time yet, as we have forked out a lot of money this year on a replacement fan and now a gas valve... pretty unimpressive for a boiler that's only 3 years old.

 

[wiggikins]

That's Life!!

 

[gas4you]

Thats Ideal

 

[Corgigrouch]

But not in an Ideal life....

Ok I'll get my coat...

 

[ollski]

I have heard plenty of their gas valves buz but nothing like the volume that you are talking about

i had a modureg solenoid fail on a midas the other week, that was at the back of the house and I could hear it sat outside the front in the van with the heater on!