Radiator Vibration noise

[paragboy]

I recently moved house, as the existing boiler was in poor condition I had a new Glow Worm Condensing boiler installed.
When the heating is, occasionally there is a rattling or humming noise coming from two of the radiators. If I adjust the thermostat on the radiator slightly the rattling goes for a while.
Any advice on resolving this problem before I call out the plumbers would be much appreciated.

 

[just-thinking]

are all your radiators fitted with thermostatic valves noisey ?

 

[ChrisR]

Turn down the valves at the rads' other ends while they're humming, until the noise stops. There are "better" solutions, but that's the cheapest if it works!

 

[kevplumb]

make sure they are on the right end of the rad
or make sure they are bidirectinoal
is the bypass open enough

(and thats after the spell checker )

 

[paragboy]

Kevplumb --> The thermostats are on the nearest side to the boiler.
No idea if they are bi-directional is there anyway that I can tell.
Not sure what you mean by the bypass.

ChrisR --> Almost closed the valves right down, it stopped the noise for a while, unfortunately it has returned.

just-thinking --> 4 out of the 7 radiators have thermostats, I think all have been noise at some point, but 2 of them more so, and I have not noticed the other 2 lately.

Thanks for your help, any more help is much appreciated.

 

[Diyisfun]

I had one rad that was noisy, it was fitted with a bi-directional t/stat valve, I moved it to the other end. Problem sorted.

 

[felix]

It's not a question of proximity to boiler. It's about direction of water flow. If you fit a standard, ie not bi-directional, valve at the return end of a radiator then, at some critical opening, it is likely to vibrate. I know because I've got one! From what Diyisfun says, bi-directional valves aren't foolproof either.

When you check the flow direction through your radiators don't overlook the possibility that some dipstick has put the pump in backwards! Start with cold radiators, switch on the heating and see which pipe gets hot first.

The bypass, if you have one, is a small pipe with a valve in it which allows some water to flow round the pump and boiler only, bypassing everything else. It's purpose is to allow some small movement through the boiler when there is nowhere else for the pumped water to go. That valve should be almost fully closed. Select CH only, turn off all the radiators and open the bypass just enough to stop the boiler from kettling or popping it's overheat thermostat

 

[doitall]

The main purpose of a by-pass is to stabilize/reduce the system head as the thermostaic valves close, and to remove heat from the boiler on shutdown.

 

[kevplumb]

youm to old to remember systematic head

 

[doitall]

youm to old to remember systematic head

Daddy always said;

If all else fails use your head

 

[breezer]

no one has mentioned that trv's usually have an arrow indicating direction of flow

 

[doitall]

no one has mentioned that trv's usually have an arrow indicating direction of flow

But I already knew that

 

[breezer]

paragboy (who asked origonal question) might not

 

[doitall]

paragboy (who asked origonal question) might not

This is true

Tell me if it has 2 arrows does the water go both ways or just one way.

Talking of arrows, on the service valve the arrow does not indicate the flow but the pressure direction.