"White" noise from central hetong

[JonathanTaylor]

My central heating has recently started making what I can best describe as white noise. It's pretty non descript ( not noticeably bubbling) just constant shwoosing and noticeably louder than normal. It's not specifically bad at the boiler but really noticeable in certain rooms. Any ideas?

 

[dcawkwell]

Open the radiator valves a bit.
There will be more noise from the valves as the water tries to squeeze
through a valve that is nearly closed.

 

[Robiow70]

What is your system? Backboiler/combi

 

[JonathanTaylor]

Cheers, I'll try opening a few valves a bit. The system is a boiler and tank - not sure of terminology, but it's not a combi.

 

[Robiow70]

You may want to check the feed/expansion tank in the loft as the float valve may have become stuck?

Or they may be sludge in the bottom of the tank, not allowing water to refill the centeral heating system.

Hope this helps Rob