Drayton TRV4 Thermostatic Valve, Head Only, Chrome & White

Reviews

Mark Phillips

Great to see Drayton still producing these after so many years; we bought our first ones eighteen years ago. They are easy to fit and I have found them to be very reliable BUT be aware of why the one that you are replacing failed: if it was because of crumbling of the plastic around the base of the head then, according to Drayton, this is because of seepage of central heating fluid through a worn gland seal onto the plastic. There are many one-star reviews where buyers have complained of early failure and this may be because they did not attend to the seepage when they fitted the new head.

You may be able to fix the problem by giving the gland seal about an 1/8th turn clockwise, indeed Drayton recommend doing this annually until there is no more travel. The gland seal kit (tool and two seals) is part number 07 35 009.

Otherwise it is a simple matter to replace the gland seal: there is a special tool for this or you just turn the seal using long-nosed pliers inserted into the lozenge shaped grooves. I have knocked off one star because I think that it would be helpful if there was an instruction on or in the box covering both the seepage issue and the fix, and perhaps a gland seal bundled with the head; after all, most people will probably be buying only the head because an old valve head has failed. There is no need to drain the system.