noise in central heating pipes

[Felicity.H]

Hi, recently heard some sharp noises from the central heating pipe about 15 minutes since the boiler switch on. There are mixed types of noises actually: most of them are popping noise, but sometimes banging noise and howling noise. The boiler was leaking in the beginning, so we called the BG engineer to get it repaired. The engineer tried bleeding the air on the radiators, and no air was seen. Now the engineer advised us that the boiler is OK and the boiler works so far so good, but the noise is really annoying. The Boiler is Glow-worm 24ci and about 5 years old. By the way, all the radiators can warm up very quickly.

Please advise what problem it could be, and any solution to eliminate the noise. Many thanks.

 

[simond]

If its about 15mins after you have switched on I suggest you check to see if you have thermostatic valves on the radiators.

The older type had to be on the flow pipe only, and if they are fitted the wrong end you can get some strange noises reverberating through the pipes as they close. This is typically 15-30mins after the heating comes on, because it takes that long for the room to warm up.

Most modern TRVs can be fitted either end to make our lives easier.

One direction valves usually have a single arrow on the valve casting, bidirectional ones have a double headed arrow. Finally, the flow pipe is the hottest of the two.

 

[Felicity.H]

Many thanks Simon.

There are thermostatic valves on the radiators. They modern TRVs as I saw one arrow on one direction and another arrow insides the circle to another direction, and they were installed about five years.

When I said about 15 minutes, it could be between 15 and 20. The noise woke me up in the early morning so I have to switch boiler off.

Advice please -- I really wish to sort it out before it is getting too cold -- your help will be much appreciated.