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.
Dave - The Medway Handyman
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.
In an earlier contribution to this discussion, Mike P
No, you need to:
* Drain the remove the affected radiator (turn off both valves, 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)
* 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
* 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, re-pressurise the
system and bleed the rad
 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
 Use lots of old towels to avoid getting any indellible black gunge on
Depends on if you are replacing the wet bit of the valve and how brave
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
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).
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, 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).
 If you have not got those a pair of decent sized carrots can be
pressed into service!
In an earlier contribution to this discussion, John Rumm
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.
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 ? :-)
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.