Noisy radiators?

[davecon1]

Hi there

Recently I've noticed that I can hear water 'flowing' through certain radiators in the house (mainly the large double convectors but also a towel rad) when the heating is on. I've found that by turning the thermostatic valve either a slight bit up or down the noise disappears, only to reappear a bit later. It's driving me mad in the morning!

All the radiators have been bled and I'm assuming they are balanced but I know that the system was not power flushed when the boiler was installed 3 years ago so that has to be done again- lucky me.

Any advice would be greatly appreciated.

Thanks

 

[Whitespirit66]

It is most likely to be coming from the restricted flow through the thermo. valves. Thats why the sound changes when you turn the valves. Is it a hissing noise? Poss as they close as the system heats the rooms. Does your boiler or rad pipework have an automatic bypass?

The hall/room rad where the room stat is locate shouldn't have a thermo. valve on it. You could try opening both valves on this rad, to act as a bypass.

Also, do your thermo. valves have directional arrows on the metal valve bodies. Does the water flow in the same direction as the arrows?

What make are the thermo. valves? Some budget brands may be noisier/

 

[davecon1]

Thanks for the quick reply.

A few months ago there was a hissing noise from the valve (which stopped when I turned it) but that seems to have stopped for a few months.

I've got no idea about the automatic bypass but will find out when the plumber comes back to flush out the system.

The stat is in the hallway and the radiator there does have a thermo valve on it but doesn't make any noise! As far as I can see all the arrows are pointing in the right direction and the most of the valves are the same around the house and think are good quality. I might try an experiment and take one off and see what happens.

The strange part is the my bathroom rad makes the water flowing noise even when the valve is turned off.

Thanks

 

[Whitespirit66]

Keep the both valves on max in the hall at all times. You don't want the room stat and hall rad thermo. valve fighting each other.

Also, the hall rad might act as a bypass, ie. if most/all thermo. valves closed down, the boiler still has a rad to pump through.