How to Fit a Honeywell evohome HR92 TRV (UK)
Fit a HR92UK smart head onto a UK radiator. Drain, isolate, PTFE, refill and balance.
Honeywell
Part
Honeywell evohome HR92 — HR92UK smart head. Confirm 15 mm or 22 mm tail before ordering.
Drain and remove
Isolate boiler. Drain enough to drop the affected rad — usually 2–3 L per rad below flow level. Undo old valve with two spanners to prevent copper twist.
Fit and balance
4–5 wraps PTFE clockwise on the tail. Nip up the union. Refill, add inhibitor, bleed. Balance by closing the lockshield to give an 11 °C ΔT across the rad at design flow.
Frequently asked questions
- Can I fit a Honeywell evohome HR92 on the flow or return?
- Bi-directional TRVs (most modern) fit either way. Legacy uni-directional valves must be on the flow — check the arrow on the body.
- TRV in bedrooms?
- Building Regs Part L requires TRVs on all rads except the room with the room stat.
Shop the spares
Browse radiator & heating — 3,680 live parts.
View Radiator & Heating