Vaillant 0020266328 vs 0020269259: Same Plug, Different Pack

The short answer

Vaillant part numbers 0020266328 and 0020269259 are the same cooling coding plug — the small blue plug that unlocks cooling on a compatible Vaillant aroTHERM Plus heat pump. They are functionally identical and interchangeable.

Both have been compared side by side by the eBay seller who sells them (boarder895): same blue plug, same connector, same internal stamping. This is what the site calls Verified Dual-MPN — two manufacturer part numbers, one physical component.

What actually differs

The packaging and the label. 0020269259 comes in an original Vaillant box labelled “Coding plug, cooling function” — Vaillant’s own description of what the plug does. 0020266328 comes in a Vaillant small-parts bag labelled with the part number only, with nothing on the pack to say it is the cooling plug.

And the price. The boxed 0020269259 costs several times as much as the bagged 0020266328. You are paying for the box and the label — the plug inside is the same.

Which one should you order?

Choose the boxed 0020269259 if your installer, quote or paperwork names 0020269259 specifically, or if you want Vaillant’s “cooling function” label on the box. Otherwise, choose 0020266328: it does exactly the same job for a fraction of the price.

Either way, check the plug suits your heat pump. It is listed for the aroTHERM Plus range — VWL 35/6, 55/6, 75/6, 105/6 and 125/6. For any other model, confirm against your installer manual or with a Vaillant-approved installer first.

Frequently asked questions