What is this my radiators make?

3 Dec 2018
Reaction score
United Kingdom
Hi all,

Finally I got my smart thermostat (drayton Wiser) installed. It took me a bit time but with help of this forum we got it working :)

So, phase two is to replace my existing TRV's with wiser ones. My radiator valves are not the standard ones. As wiser TRV don’t fit it. So from wiser valve guide https://wiser.draytoncontrols.co.uk/sites/default/files/documents/4369_adapter_guide_2pg_v4_web.pdf , I thought mine is Herz! The hart shape on the valve. So bought couple of this converters as per Drayton specification. Unfortunately this don't seem to fit on properly either. What I mean is that, diameter is perfect about 28mm, but it will not screw on as the top of radiator valve nob is too long.Also I wonder if I could somehow push that tip of valve a bit more in. Then I could can screw the converter on?Or i have to drain the central heating first, depressurize it?

Photos of radiator valvs attached.


  • 20181126_083057.jpg
    150 KB · Views: 85
  • 20181126_083100.jpg
    84.3 KB · Views: 86
  • 20181126_230556.jpg
    104.5 KB · Views: 79
Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links