What is a four-way or multi-purpose radiator key?
The parts of a four-way radiator key are:
Also known as a utility key or services cabinet key, this type can be used on the drain-off cocks, also known as drain taps or drain valves, on some radiators.
Four-way keys are usually made of brass, galvanised or zinc-coated steel, an alloy (a mixture of two or more metals), or tough plastic. These materials ensure the key will not rust.
For certain kinds of maintenance work, all the radiators of a system might need to be drained.
Making use of a radiator drain cock near to an outside door, a hose can be attached to the drain cock or valve and the valve opened with the appropriate leg of the key.
This image shows some of the uses of one kind of four-way key.
Most four-way keys have fittings at the end of their legs to operate some radiator drain-off valves; gas, water and electric meter cupboards, as seen here; some air conditioning units; some stop valves; mains consoles; some square headed gate valves; some central heating pump cocks; and some outside taps.
However, the keys are not all the same - they may have some fittings but lack others - so it's best to check that a particular key fits the kind of fittings and fasteners you want to open and close.
Some four-way keys are ideal for turning what are known as lockshield drain-off valves. These valves have a collar of metal around the square head to prevent operation except by the owner of the key.
The appropriate leg of a four-way key fits perfectly inside the collar and over the square head.
Radiator drain valves can have different pipe sizes. Some four-way keys will fit square spindles on valves with 1/2 inch, 3/4 inch and 1 inch pipe connections.
Some four-way keys have a leg that fits air release valves for bleeding radiators.
The four-legged design is useful - two of the three legs not in use make very effective handles for turning sometimes stubborn valves