Whistling Glow worm Spacesaver 50BF

[mgf]

The system is a pumped CH and gravity HW.

I recently de-sludged, due to kettling, using DS-40. Now all is quiet apart from a low pitch whistling noise about 30 seconds after the boiler fires up, lasting for about another 30 seconds then everything's ok again.

Also, the nearest rad to the boiler keeps getting some air in it.

Anyone any ideas of what it could be?

 

[corgiman]

I really dont mate sorry never heard anything like that.

might be abit of trapped air I suppose

 

[ChrisR]

Old glowies, and others, often do it. Try boiler silencer (liquid) but praying may be more effective. We get drones, ghosts, concordes taking off, trains, kettles, flat tyres... The air thing should get better, slowly.