What Does the Vaillant Cooling Plug Look Like?

The plug itself

The cooling plug is a blue plug body on a white two-pin connector, a few centimetres long, with a small printed label on the side. Inside is a resistor — which is why installers also call it the cooling resistor or code plug.

Both part numbers, 0020269259 and 0020266328, are this same plug.

The two packs

0020269259 comes in Vaillant’s box, with a label that reads “Coding plug, cooling function”, a drawing of the plug, the part number and a barcode.

0020266328 comes in a Vaillant small-parts bag. Its label shows the part number and barcode, but no description of what the plug does — which is why it is easy to miss when searching for a cooling plug.

Is one already fitted to your heat pump?

Checking means opening the heat pump to look at the coding-plug position — a job for a competent installer, with the power isolated. Ask for it to be checked at your next service.

There is also a quicker clue: if cooling already appears as an option at installer level, the heat pump already recognises that cooling is permitted.

Do not confuse it with other coding plugs

Vaillant uses coding plugs for other appliance options too, so a plug of a similar shape is not necessarily the cooling one. Go by the part number on the packaging: 0020269259 or 0020266328.

Frequently asked questions