Compatibility
Vaillant aroTHERM Plus Model Numbers: VWL 35/6 to 125/6
From VWL 35/6 to VWL 125/6 — five sizes, one cooling plug
Every Vaillant aroTHERM Plus carries a model code such as VWL 75/6 on its data plate, and the number tells you the heat pump’s size. This guide decodes the five aroTHERM Plus sizes, explains how to read the rest of the code, and shows how the cooling plug relates to each one.
Updated
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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 five aroTHERM Plus sizes
The aroTHERM Plus range comes in five sizes. The number in the model code reflects the nominal output: VWL 35/6 is the 3.5 kW unit, VWL 55/6 the 5 kW unit, VWL 75/6 the 7 kW unit, VWL 105/6 the 10 kW unit and VWL 125/6 the 12 kW unit.
VWL marks a Vaillant air-source heat pump. The same family prefix appears on other Vaillant air-source ranges, which is why the number after it matters.
Reading the rest of the code
On the data plate you will often see more after the main code — for example a letter, a voltage, or a suffix such as S2. Those extra characters identify the exact variant of your unit.
Note the whole code exactly as printed. It is what an installer, or Vaillant, needs in order to confirm options such as cooling for your specific heat pump.
Which sizes take the cooling plug
The cooling plug is listed for all five aroTHERM Plus sizes, and it is the same plug for every size. It is sold boxed as Vaillant 0020269259, labelled “Coding plug, cooling function”, and as the identical 0020266328 in a Vaillant small-parts bag.
Whichever size you have, an installer fits the plug and then enables cooling in the installer menu. Cooling also needs suitable emitters — fan coil units, or underfloor heating with dew-point control.
Where to find your code
The model code is printed on the data plate, usually on the outdoor unit casing. The same details normally appear on your installer’s commissioning paperwork.
The five aroTHERM Plus sizes at a glance.
| Model code | Nominal size | Cooling plug |
|---|---|---|
| VWL 35/6 | 3.5 kW | Listed — 0020269259 / 0020266328 |
| VWL 55/6 | 5 kW | Listed — 0020269259 / 0020266328 |
| VWL 75/6 | 7 kW | Listed — 0020269259 / 0020266328 |
| VWL 105/6 | 10 kW | Listed — 0020269259 / 0020266328 |
| VWL 125/6 | 12 kW | Listed — 0020269259 / 0020266328 |
Frequently asked questions
What does VWL 75/6 mean?
It is the 7 kW Vaillant aroTHERM Plus air-source heat pump. VWL marks a Vaillant air-source heat pump, and 75 reflects the 7 kW size.
Does the size change which cooling plug I need?
No. The same plug is listed for all five sizes, from VWL 35/6 to VWL 125/6.
What does S2 mean at the end of the code?
It is part of the variant code. Vaillant’s aroTHERM Plus product information says S2 units can have cooling activated later with an optional accessory. The cooling plug sold on eBay is listed for all five VWL ../6 sizes; confirm against your own unit’s documentation.
My code is not one of these five — what now?
Then your heat pump is not an aroTHERM Plus, or it is a variant to check. Ask a Vaillant-approved installer to confirm how cooling is enabled on your exact model before ordering anything.
Does the plug fit the newer aroTHERM Plus (v2)?
The listings name the VWL ../6 sizes above. A UK trade supplier, Midsummer Wholesale, states that 0020269259 is compatible with both older and newer (v2) aroTHERM Plus models — their statement, not verified here. Check your installer manual or a Vaillant-approved installer before ordering for a newer unit.
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
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