Replacing a Wide Towel Radiator: Pipe Centres and Fit

Quick answer: For a replacement wide towel radiator, measure connection centre lines, body dimensions and wall projection separately. Our ranges use pipe centres 50mm less than body width, but existing valve and pipe dimensions still need checking before a like-for-like replacement is confirmed.

By M Tasan · Published 4 November 2026

Part of our wide towel radiator buying guide.

Why matching body width is only the beginning

A replacement can look almost identical to the old towel radiator and still need plumbing changes. Overall width describes the body, while pipe centres describe the spacing of the connection centre lines. The valves link the radiator to the pipes and add their own dimensions to the installation.

Start with the wide towel radiator buying guide if you are still deciding on the general size. This checklist is for the next stage: deciding whether a shortlisted rail can replace the one already on the wall.

Record five measurements

1. Body width and height: measure the metal radiator itself, keeping valve measurements separate.
2. Connection centres: identify the centres of the radiator connections. Do not measure from the outer edges of valve caps.
3. Existing pipe positions: note whether pipes emerge from the floor or wall and their spacing.
4. Wall projection: record the position of the connection centre line and the front of the radiator relative to the finished wall.
5. Valve arrangement: photograph the connections and note how much room is available for operating or replacing them.

If a connection is concealed or the centre line is unclear, ask the installer to measure it. Do not loosen live plumbing merely to obtain a measurement.

Our width-to-centres examples

In our towel radiator ranges, a 550mm body has 500mm pipe centres; a 650mm body has 600mm centres; and an 800mm body has 750mm centres. These refer to the selected rail’s connection spacing. They do not automatically establish the distance between your existing floor pipes after valves are fitted.

You can compare 550mm-wide black towel radiators, 650mm-wide black towel radiators and 800mm-wide black towel radiators, or use the complete 550mm to 800mm width table. Always check the individual product specification as the final reference.

Will the old brackets line up?

Do not assume that matching width and height means matching bracket positions. Tube layout, bracket design and adjustment range can differ. Your installer should assess the wall, select suitable fixings and plan any redundant holes before fitting the replacement. Supplied brackets do not establish that the existing plugs or wall structure are suitable.

Take photographs before removing the old rail. Include a wide view of the wall and close views of the connections. Note any tiled surfaces, concealed services or furniture that limit access. This gives an installer a more useful starting point than a product name alone.

Can you keep the existing valves?

Possibly, if their connection type, condition and dimensions suit the new rail. Reuse is a compatibility decision, not a guaranteed saving. New straight or angled valves may change the required pipe arrangement. Our valve and clearance guide for wide rails explains the questions to ask.

If changing heating controls, Energy Saving Trust’s heating-controls guide explains the different roles of room thermostats and radiator valves. A manual valve is not the same as a thermostatic valve; ask your installer how the bathroom should be controlled within the whole system.

Recheck output when replacing

A rail that fits the old connections may still provide a different amount of heat. Compare the exact new model with the room’s requirement, especially after changes to the heating system, insulation or room layout. Our output and low-temperature guide covers the figures to request.

Your replacement handover note

Give the installer the proposed product link, selected size, finish, connection spacing, valve choice and photographs. Ask them to confirm pipe alterations, bracket positions, wall suitability and heating performance before installation is booked. That short check is more reliable than ordering from body width alone and trying to make the rest fit afterwards.

Sources and scope

• Energy Saving Trust: heating controls

External sources support the general heating or safety points identified above. Product dimensions, supplied fittings and range examples refer to Cheap Radiator’s listings; confirm the selected product before ordering. This is buying guidance, not an installation specification.