Vaillant 0020269259: The Coding Plug, Cooling Function

What 0020269259 is

Part 0020269259 is a genuine Vaillant coding plug: a small blue plug on a white two-pin connector, with a resistor inside. Vaillant’s own label names it “Coding plug, cooling function”, and it is the part Vaillant lists for cooling.

When it is fitted, the heat pump’s control electronics read it and recognise that cooling is authorised — the state this site calls Authorised Cooling Mode.

What it does — and what it does not do

It unlocks cooling. On a heat pump supplied without cooling, the cooling option stays unavailable in the installer menu until the plug is fitted.

It does not switch cooling on by itself, and it does not make radiators cool. A Vaillant-approved installer still enables cooling in the settings, and the home needs emitters that can cool — fan coil units, or underfloor heating with dew-point control.

Which heat pumps it is for

It is listed for the aroTHERM Plus range: VWL 35/6, VWL 55/6, VWL 75/6, VWL 105/6 and VWL 125/6 — the 3.5 to 12 kW monobloc air-source units. Some aroTHERM Split installations use it too.

For any other model, including earlier aroTHERM units and flexoTHERM or flexoCOMPACT ground-source heat pumps, check your installer manual or ask a Vaillant-approved installer before ordering.

The same plug for less: 0020266328

Vaillant also supplies this exact plug as part 0020266328, in a Vaillant small-parts bag labelled with the part number only. The two have been compared side by side: same blue plug, same connector, same internal stamping. This is what the site calls Verified Dual-MPN.

The difference is the box and the label — and the price. On eBay, 0020266328 costs a fraction of what the boxed 0020269259 does.

When the boxed 0020269259 is the right buy

Choose 0020269259 when your installer, quote or paperwork names it by number, or when you want Vaillant’s “cooling function” label on the box — for example if you are fitting it for a customer who expects to see it. If you just need the plug that unlocks cooling, 0020266328 does exactly the same job.

Both are sold new and unused on eBay by seller boarder895, with 100% positive feedback and on eBay since 2003. You pay through eBay’s checkout and your purchase is covered by the eBay Money Back Guarantee.

Frequently asked questions