How to Identify My Old Radiator Valve (and Find the Right Replacement)
When a radiator valve fails or leaks, the hard part is usually working out exactly what you've got so you can replace it with the right part. Here's a simple checklist to identify your old valve.
1. What type of valve is it?
There are three common types: a thermostatic radiator valve (TRV) has a numbered head you twist to set a temperature; a manual valve has a plain wheelhead or handle for on/off/flow; and a lockshield (usually with a plastic cap) is the balancing valve on the other end of the radiator. Identify which one has failed before ordering.
2. Measure the pipe size
Most UK homes use 10mm or 15mm copper pipe into the valve. Measure the outside diameter of the pipe the valve connects to. 15mm is by far the most common; 10mm (microbore) is often found in newer or extension pipework.
3. Angled or straight?
Look at how the valve meets the pipe. If the pipe comes up out of the floor and turns 90° into the radiator, you need an angled valve. If the pipe runs straight into the radiator horizontally, you need a straight valve. Corner and H-block valves also exist for special layouts.
4. Check the connection
Standard compression fittings use a nut and olive onto copper pipe. Some systems use push-fit. Note the radiator tail size too (usually 1/2" BSP) so the new valve matches.
5. Still not sure? Send us a photo
If you can't tell what you've got, take a clear photo of the valve (and any markings) and use our Find My Replacement service — our specialists will identify the correct valve and confirm it before you buy.
Need help finding the right part?
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