Noisy hot water

[jfeat]

I have a pumped graivity fed ch system, run by a gas boiler. I flushed the system through about 4 years ago, & it ran almost silently for a couple of years. At some point the hot water system started getting noisy as if it needed bleeding, whilst the ch & radiators still run very quietly. I frequently release air from the bleed valve next to the hot water tank, but it hardly makes any difference. The hw side of the system keeps making swirly noises as if air is trapped somewhere. None of the radiators need bleeding. How can I sort this out? Any suggestions appreciated.

 

[stevetheplumber]

I have a pumped graivity fed ch system, run by a gas boiler. I flushed the system through about 4 years ago, & it ran almost silently for a couple of years. At some point the hot water system started getting noisy as if it needed bleeding, whilst the ch & radiators still run very quietly. I frequently release air from the bleed valve next to the hot water tank, but it hardly makes any difference. The hw side of the system keeps making swirly noises as if air is trapped somewhere. None of the radiators need bleeding. How can I sort this out? Any suggestions appreciated.

realy you have answered your own question if fushing it four years ago worked it probably needs to be done again maybe this time it should be powerflushed and have inhibitor added

 

[jfeat]

An inhibitor was added when last drained. I find it surprising that the heating is virtually silent, whilst the hw is so noisy, I would have expected both to behave in the same way.