Bathroom Heating jargon buster

We know that not everyone is as passionate about bathroom heating as we are, so to save you puzzling over any terms, check out our jargon buster which explains any terms which may be unfamiliar.

Angled valve

A radiator valve which is used when the valve fittings are either on the side or on the underside of the heater, standing proud of the wall.

Baseboard heater

A space-saving heating unit which is attached to the baseboard and gently heats the room.

British thermal unit (BTU)

This measures the amount of energy required to heat one pound of water by one degree Fahrenheit. BTUs are used to calculate the size and power of radiator required, based on the size of the room and the existing or planned insulation.


Dual-fuel radiators are plumbed and wired into both the existing central heating system and the mains electricity. This enables them to run off the central heating when it is on and from the mains at times when the central heating is off, such as during the summer.

Expansion gap

The gap which should be left around the edges of a timber floor when fitted with underfloor heating, in order to accommodate for the natural expansion and contraction of the wood as it heats and cools.

Forced air heating

Forced air heating draws in air from the room over a heat exchanger and pumps it back in, maintaining healthy air circulation and filtering.

Heated towel radiator

A bar radiator designed for warming bath and hand towels which also heats the bathroom.

Heat exchanger

The equipment inside a forced air heater which warms the air before recirculating it.

Panel heater

A wall-mounted bathroom radiator which usually uses forced air heat.

Pipe tails

Chrome pipe which can be used to connect a towel rail valve to the floor.

Radiant heating

A heater which uses special bulbs, wires or hot water pipes, warming the people and objects in a room rather than the surrounding air.


Retrofitting refers to the practice of fitting something after building, such as pulling up an existing floor to install underfloor heating.

Room thermostat

A device which senses the temperature of the surrounding air and switches the heating on or off according to the current temperature of the room.

Straight valves

Radiator valves which are used when the valve fittings are on the underside of the heater and come out of the floor.

Thermostatic radiator valve (TRV)

A valve which operates like a room thermostat but only for the specific radiator it is attached to.

Wet system

A system of underfloor heating, involving a series of hot water pipes which heat the room from underneath the floor.

Wire system

A system of underfloor heating which uses electrical wiring to heat a room from underneath.

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