Are My Radiator Valves Compatible With Smart TRV’s?

The Honeywell Home evohome HR91 & HR92 Radiator Controllers, and the Drayton Wiser Smart Radiator Thermostats, are compatible with most manufacturers of Thermostatic Radiator Valves (TRV’s) with M30 x 1.5mm threaded thermostatic heads.

However, they are not always compatible with current and existing TRV’s due to cheap imports and different manufacturing standards. We also recommend that consideration be made to replacing TRV’s over 15 years old, as they may not function properly due to age which would prevent the evohome system from controlling the heating system correctly.

For a TRV to somewhere near compatible, the TRV should look something like Honeywell’s VHL120-15A

The dimension across the diameter of the thread should measure 30mm and the ‘thread pitch’ should measure 1.5mm (thread pitch is the measurement of one thread to the next).  The pin height when measured from the top of the valve thread should measure approximately 14mm and the radiator valve must fully close when the pin is pressed no more than 4mm (most thermostatic radiator valves will close with only 2mm of pin movement).

A short video below demonstrates what you should look for when deciding if your radiator valve is compatible with Honeywell evohome Radiator Controllers.

We have compiled a table below listing some of the popular current and existing TRV’s that fit with the HR91 & HR92 Radiator Controllers and Wiser Radiator Thermostats (we appreciate they are not all listed here). We also have some Honeywell TRV adapters available to purchase in our shop that will allow certain non-compatible TRV’s (listed below) to accept Honeywell evohome HR91 & HR92 Radiator Controllers.

If you are still unsure about the compatibility of your TRV, please email us at sales@mwphs.co.uk and we may be able to identify what TRV(s) you have. We cannot promise to identify all TRV’s and in cases where we are not sure, we would recommend replacing them with the valves manufactured by Resideo for the evohome system, available to purchase on our website.