Thorn Olympic, can I stop it kettling?

[IanDudley]

Having recently moved into a new house, we have inherited an aged Thorn Olympic (I cant see any more specific model no.) boiler which is providing hot water to a tank and running the central heating system, which is an open vented radiator system covering a three bedroom detached house over two floors.

Since the weather turned cold and the heating was switched on, we've noticed (you can hardly miss it) that the boiler constantly bangs when running, which I believe is referred to as kettling? When burning it sounds like a pan of popcorn popping, with a couple of bangs a second. It's loud enough that you can hear it throughout the house, which is obviously a real pain.

We had the boiler serviced by a Corgi engineer not long ago, as a general safety precaution with a new boiler, and he confirmed the noises are caused by deposits within the boiler. However, he also said that there was basically nothing we could do about it, as the boiler is so old that any attempt to use a chemical flush on it would likely destroy it. The only recourse we seem to have is a new boiler, which will apparently cost a couple of grand.

I don't have that sort of money right now, even before the current economic fun and games cash was tight as we pushed the boat out on buying the house. But I'd rather not spend the next couple of years with the heating sounding like a machine gun.

Can anyone suggest any options here? Does it sound sensible that the chemical flush would kill the boiler, or are there any other things that can be done for kettling which would be less dangerous?

Any thoughts or advice appreciated.

Thanks in advance,

Ian

 

[gas_man_gaz]

flushing genrally dosnt stop the boiler kettling, id try some fernox silencer (about £30) drain 1 rad and inject stright into it through the bleed

 

[IanDudley]

flushing genrally dosnt stop the boiler kettling, id try some fernox silencer (about £30) drain 1 rad and inject stright into it through the bleed

What about the suggestion that this sort of thing might kill the boiler? Do they get that fragile when old? I think its getting on for 20-30 years old now.

 

[swbjackson]

The boiler noise silencer is a different thing to a flushing chemical. I've never had a lot of success with them but it may be worth a try.

You definitely need to start saving up for a new boiler. If you leave the old one crashing away it will kill itself anyway.

Mike

 

[Agile]

flushing genrally dosnt stop the boiler kettling, id try some fernox silencer (about £30) drain 1 rad and inject stright into it through the bleed

What about the suggestion that this sort of thing might kill the boiler? Do they get that fr agile when old? I think its getting on for 20-30 years old now.

The Sentinel X200 is pretty mild and I have never heard of any case of it causing any problem.

My view is that its a smaller risk in using it than running the boiler while its kettling as that is quite risky as it can cause the heat exchanger to crack as a result of differential expansion.

Tony

 

[Slugbabydotcom]

Kettling is the nature of this beast. I have had one in mine for about 25 years and I wouldnt swap it or a new one because theres so little in there to go wrong.
What I did with mine was to find a sweet spot where the boiler stat is at about 3½ Kettling is minimal and the water is hot enough
A chemical flush or better still a powerflush will help reduce kettling even further but even when they were new they were still prone to it.
System will be open vented so as long as there is water in it I cant see how it could be dangerous even though the noise can be alarming.
A service never goes amiss. Make sure your boiler stat phial is pushed in properly. After that the only things that really go wrong are thermocouple pilot burner and injector and a gas valve, sometimes a boiler stat.
Compare that with a modern one with temp sensors, expensive PCB's fans, expensive gas valves air pressure switches, sensitive heat exchangers [Yours is a bulletproof lump of cast iron!]condensing HEs, PRV's, pressure vessels and much more besides if you opt for a combi.
Long may these dinosaurs reign