central heating hissing

[bonsai1975]

I have fitted a new CH system myself. I have a combi boiler a Halstead Acer HE 30. I have five radiators, three with thermostatic valves and two with just lockshields. All my main pipework is 22mm but any pipe only supplying a single radiator is only 15mm - some radiators have long runs of 15mm (up to six metres).

I get a hissing sound from my radiators - sounds like water is travelling to fast through the sytem. I cannot reduce the pump rate in my boiler.
Adjusting the lockshields does reduce the noise but even when they are fully open there is still a noise. My TRV's are bi-directional and are all correctly installed. ANy thoughts ?????????

 

[MasterAbacus]

Have you tried draining the system and refilling it?

How did you do the install? Im guessing solderd copper joints?

Were they pre solder (Yorkshire fittings) or plain fittings?

 

[bonsai1975]

no have not tried draining and refilling since the system was first commissioned. what might that do ?

joins are mainly compression.

 

[MasterAbacus]

I was thinking along the lines of a drain to try lear out any debris that me floating about... but thats manily caused by dodgy soldering.... you haven compression, so shouldnt be that...

Could be an airloock thats taking time to get through the system...

Or maybe a dodgy trv...

Id still be tempted with the drain out tho...