Creating free energy

Towel rails typically only provide a small amount of heat, and when towels are placed over the rails, they will effectively insulate the rail surfaces, further reducing heat output and raising return temperatures.

Recommended by CP1 (2020) as best practice, installing a Pressure Independent Return Temperature Limiter (PI-RTLV) on the towel rail (as opposed to the collective space heating return) guarantees low return temperatures from the towel rail without compromising function.

Rt40 PI-RTLV Configurator

All our Rt40 Pressure Independent RTLV sets are bespoke to the specific building requirements. To help you choose the correct towel rail valve set you can use the configurator.

This will take you methodically through the selection process, with pictures of each component, info buttons to let you know when and what component to choose, as well as an automated product code generator.

Rt40 Configurator Screen

The use of a return temperature limiter on heated towel rails is particularly useful as the output (and hence return temperature) is otherwise determined by the number of towels

Heat Networks Code of Practice (2020)


Minimise waste, maximise efficiency

From reducing energy waste, improving the efficiency of the heat plant, lowering heating bills and reducing set-up & commissioning time, the Pt40 offers 12-15% energy saving compared with traditional TRVs.

Best practice

Pressure independent

Pressure fluctuations due to varying load conditions require a constant automatic balancing to maintain a comfortable and efficient heating system.


No more no less

With a simple setting scale (1-7), the Rt40 can permanently and reliably control the heat delivered to individual towel rails.  

40°C Maximum

Return temperature limiting

Protect the network’s performance without compromising the comfort of occupants.

Rt40 PI-RTLV documents

Please find relevant links for further reading below, or visit our downloads page.

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