I've recently installed some TRV's on a few of my radiators, but when the temperature is just below the shut off point they seem to start whistleing! It seems to be on every radiator so it's not just a rouge TRV.
I fitted the Pegler Terrior II TRV's from Screwfix as I was told Pegler was a reputable make. Could anyone shead any light onto why this is happening and if there's a solution (apart from replacing them all!).
On the bright side, it does negate the need for an alarm clock in the morning!
Cheers Phil