Whistling TRV

[The Medway Handyman]

About 18 months ago I had a new boiler fitted in Handyman Towers and fitted TRV's (Wickes) to the rads.

The one in the spare/granddaughters room has suddenly started whistling. AFAIK they are of the sort that can be fitted with the flow either way.

Loosening the TRV body stops it for a while.

Can't work out why its suddenly started and none of the other ones whistle.

Any ideas?

[Roger Mills]

Perhaps it's just happy?

[The Medway Handyman]

I thought it was whistling because it didn't know the words :-)

[ericp]

Try opening/closing the locksheild on the other end slightly, just to change the flow of water slightly.

[The Medway Handyman]

Good tip, thanks.

[John Rumm]

IME some of the "bi-directional" ones do make a noise if used on the return - particularly as they begin to close down. I have had this with a pegler one. The only cure I found was to swap it to the other side.

[Mike P]

Just to diverse a little .... to place a TRV on a downstairs rad, do you have to drain the (combi) system to avoid wet feet ?

Mike P

[Roger Mills]

No, you need to:

• Drain the remove the affected radiator (turn off both valves[1], crack one of the union nuts and guide the water into a bowl, using a re-styled aluminium foil food dish. When empty, fully undo both union nuts, and lift off the rad)[2]

• De-pressurise the system

• Open the valve which you are replacing, and collect any water which comes out in a container - there shouldn't be much

• Remove the valve and fit the TRV to the pipe

• While the rad is off, give it a good wash out with a hosepipe (preferably outside! )

• If neccessary replace the radiator tail with the one supplied with the TRV (depending on the existing valve, you may be able to keep the existing tail if it is compatible with the TRV)

• Re-fit the rad, do up the unions, turn on the valves[1], re-pressurise the system and bleed the rad

[1] If the system has been balanced, count the number of turns needed to close the lockshield valve so that you can restore it to the same degree of openness [2] Use lots of old towels to avoid getting any indellible black gunge on your carpets

[John Rumm]

Depends on if you are replacing the wet bit of the valve and how brave you are!

You can drop the pressure by draining a little water, shut off both valves and undo a connection to the rad, and drain that into a low profile dish (cat litter tray is handy).

First have the new valve to hand with its compression nut and olive removed.

Now wrap a cloth round the pipe tail and loosen the locknut on it. Then while applying some downward pressure to top of the valve undo the nut completely - you may get some seepage.

Now the fun bit, swiftly take the valve off the pipe and stick your thumb over the pipe end. Then do the same trick again to sit the new valve on the pipe and apply downward pressure again (don't worry about getting it at the right angle to mate with the rad at this stage). Do up the compression nut finger tight, rotate the valve to its final position and tighten. If the new valve body's pipe acceptance hole is at least as deep as the previous, then you should get a good seal with the old olive. You could smear some Fernox LS-X on the olive mating face of the new valve before installation as a safeguard.

If you are quick with the above, you should lose no more than a cup full of water. Take care though, it may contain black iron oxide which will stain fabric like carpets.

Once done you can re-pressurise, and bleed the rad etc. If you want to add inhibitor to the system, then take the chance now. Before you turn the taps on to to the rad, take out the blank plug at the top and tip the inhibitor in with a funnel (or use the Fernox gel stuff in a mastic style tube that you can squirt in).

[The Medway Handyman]

I've used the patented John Rumm 'stick your thumb over the end & work quick' ploy on several occassions, but I don't think I'd have the balls to do it on a CH stsem :-)

[Mike P]

Thanx all for the info to the above .... I have removed rads before and am aware of that oooh so nasty black sludge. There are no carpets to wet or stain downstairs, so ............. practice makes perfect, methinks ? :-)

Mike P

[John Rumm]

Its easiest on a sealed CH system - you know there is only a finite amount of water, and you have a good chance of getting hydrostatic lock preventing much of it falling out.

(for the vented equivalent I have a pair of rubber pointy bungs[1], you shove one in the vent pipe and the other in the outlet at the bottom of the feed/expansion tank. That achieves the same lock effect).

[1] If you have not got those a pair of decent sized carrots can be pressed into service!

[PeterC]

Anne Summers is your 'friend'.

[Roger Mills]

I don't even need those. When I did some work on my (vented) system a couple of years ago, I installed full-bore lever valves in the main CH flow and return pipes, so I can easily isolate the whole system. At the same time, I fitted drain-off lockshield valves to all the rads. The combination of these things makes changing a radiator valve a real doddle. It's easy to drain and remove a rad and - with the lever valves turned off - it's possible to remove a single radiator valve with virtually no spillage.