FAQ Header Image (Should TRVs be installed on the flow or return pipe?)

Most modern thermostatic radiator valves are bi-directional – so can be fitted on either the flow or return pipe of your radiator.

However, it’s always best practice to fit the TRV on the flow pipe that enters your radiator.

If a non-bi-directional thermostatic valve is fitted to the return side of the radiator, it can make a loud vibrating noise when water tries to pass through it.

It’s best to check the product thouroughly before installation and look for flow indicators where possible.

To discover more about thermostatic radiator valves, take a look at our complete range of TRVs and learn why they’re important in our ultimate guide to TRVs.