Smart controls

Smart TRV noisy at night

Warning Do not attempt any electrical or gas work yourself. Always use a qualified, MCS-certified, or Gas Safe registered professional for repairs.

What you’re seeing (symptoms)

You are woken up at night by a “whirring,” “grinding,” or “buzzing” sound coming from your radiator. This happens even when you aren’t adjusting the heating. The noise is the sound of the small motor inside the Smart TRV (Thermostatic Radiator Valve) moving the pin to open or close the valve.

What’s normal vs not normal

Normal:

A brief (1-2 second) whirring sound when the heating first turns on or off.
A weekly “calibration” run (often at midday) where the valve opens and closes fully to prevent sticking.

Not normal:

The valve making noise every few minutes throughout the night.
A loud “clicking” or “hammering” sound (which may be a plumbing issue rather than a motor issue).
The valve motor running continuously for more than 30 seconds.

Likely causes (ranked)

Micro-adjustments: The room is hovering right at the “setpoint” (e.g. 18.0°C), causing the smart valve to constantly open and close by a tiny amount to maintain the temperature.
Poor calibration: The TRV doesn’t know exactly where the “closed” position is, so it’s over-working the motor to try and push the radiator pin down.
High pump pressure: Your central heating pump is set too high, making it harder for the small TRV motor to push against the water pressure.
Sticky radiator pin: The old metal pin on the radiator body is stiff or corroded, forcing the smart motor to work harder (and louder) to move it.
Battery low: As batteries fail, some TRV motors can become slower and noisier as they struggle with lower voltage.

Quick checks you can do safely

Check the ‘Quiet Mode’: Many apps (like Tado or Netatmo) have a “Quiet Mode” or “Night Mode” that slows down the motor to make it quieter, at the cost of being slightly less precise.
Adjust the setpoint: Lower your night-time temperature by 0.5 or 1 degree. This often stops the valve from “hunting” for a precise temperature while you sleep.
Re-calibrate: Remove the TRV and re-mount it, then trigger a “Calibration” or “Mounting” cycle in the app.
Check the pin: Remove the smart TRV and try to push the metal pin on the radiator down with a coin. It should move down and spring back up easily. If it’s stuck, it needs a drop of WD-40 or a plumber.

When to call an installer

If the noise is a loud “banging” or “vibrating” (this is likely “water hammer” or a valve installed on the wrong side of the radiator).
If the TRV displays a “Mounting Error” or “Motor Fault” that won’t clear.
If you want to install “low-noise” specific TRV models in bedrooms.

Questions to ask your installer

“Are these TRVs compatible with my specific radiator valve bodies?”
“Can we lower the central heating pump speed to reduce the pressure on the TRV motors?”
“Do any of the radiators need a ‘bypass valve’ to prevent pressure buildup when all smart TRVs close at once?”

FAQs

Can I make it silent? No. All smart TRVs use a small electric motor and gears, which will always make some noise. However, some brands are significantly quieter than others. Why only at night? The house is quieter at night, so you notice the sound more. Also, your heating is often in “setback” mode, meaning the valves are working hard to keep the room at a lower, steady temperature. Will it drain the batteries? If the valve is constantly “hunting” and moving, yes. Re-calibrating and ensuring the radiator pin is smooth will significantly extend your battery life. What is a ‘Pin’? Underneath the smart head, there is a small metal pin sticking out of the radiator. When this pin is pushed down, the water stops. When it’s up, the water flows. Do I need them on every radiator? Ideally, yes, for the best control. However, you should always leave one radiator (often in the hall or bathroom) with a standard valve or no valve to act as a “bypass” for the pump.\n

Written by NetZeroNow | Last updated on 2026-03-02