Part numbers & buying
Is There a Cheaper Alternative to the Vaillant 0020269259?
Yes — the same Vaillant plug, without the box
If you have priced up the Vaillant 0020269259 “Coding plug, cooling function”, you will know it is not cheap. There is a genuine Vaillant alternative that costs far less: part 0020266328. It is the same blue plug — the difference is the box and the label, not the part.
Updated
Buy the Vaillant cooling plug on eBay
Same blue plug, two packs. Choose the boxed 0020269259, or get the identical 0020266328 for a fraction of the price.
Original Vaillant box, labelled “Coding plug, cooling function”
Buy on eBaySold by eBay seller boarder895 · 100% positive feedback · 600+ feedback · on eBay since 2003 · 20+ plugs sold
The short answer
Vaillant 0020266328 is the same cooling coding plug as 0020269259. It has been compared side by side with the boxed part — same blue plug, same connector, same internal stamping — and it unlocks cooling in exactly the same way.
It comes in a Vaillant small-parts bag labelled with the part number, rather than a box labelled “Coding plug, cooling function”. On eBay it costs a fraction of the price.
When the boxed 0020269259 is still worth it
Pay for the box when the number itself matters: your installer, quote or paperwork names 0020269259, or you are fitting it for a customer who expects to see Vaillant’s cooling label. In every other case, the bagged 0020266328 does the same job for less.
Why not a home-made resistor?
Some owners online describe making their own plug from a resistor and a connector. It is not a Vaillant part, its value and tolerance are down to whoever made it, and an installer cannot verify what has been fitted inside your heat pump.
A genuine 0020266328 removes that doubt for little money: a real Vaillant plug, new, with its part number on the label.
What you keep — and what you give up
You keep
The same blue Vaillant plug, the same function — Authorised Cooling Mode — genuine Vaillant, new and unused.
You give up
The box, and the “Coding plug, cooling function” wording on the label. The bag carries the part number 0020266328 instead.
Frequently asked questions
Is 0020266328 really the same as 0020269259?
Yes. Same blue plug, same connector, same internal stamping — compared side by side. Only the packaging, the label and the price differ.
How much cheaper is it?
On eBay the bagged 0020266328 costs a fraction of the boxed 0020269259 — the boxed part costs several times as much. See today’s prices on the two eBay listings.
Will an installer fit 0020266328?
It is a genuine Vaillant part, and the plug is identical. If your installer insists on 0020269259 by number, buy the boxed version — it is the same plug.
Could using the cheaper 0020266328 affect my heat pump guarantee?
Both packs contain the same genuine Vaillant plug, so there is no non-genuine part involved either way. Whether any work on your heat pump affects your guarantee depends on your guarantee terms and on who does the work — that is a question for your installer or Vaillant before fitting, and not something this site can promise. If you want the number on the box to match a quote or warranty record, buy the boxed 0020269259.
Can I just use a resistor instead?
Some owners do, but a home-made plug is not a Vaillant part and nobody can verify it. The genuine 0020266328 costs little and removes the doubt.
Related guides
Ready to buy? Both plugs are on eBay
The plug inside is the same — choose the pack. 0020266328 is the best value; 0020269259 comes boxed and labelled “Coding plug, cooling function”.
Original Vaillant box, labelled “Coding plug, cooling function”
Buy on eBaySold by eBay seller boarder895 · 100% positive feedback · 600+ feedback · on eBay since 2003 · 20+ plugs sold
provenance: sha256:e3d83d711f0c8a57… · machine-readable: claims.json · llms.txt