How-to guide
How to find your Vaillant heat pump model number
Where to look, what the code means, and why it matters for ordering
Knowing your exact Vaillant heat pump model number makes it easy to confirm whether your unit can cool and to order the right parts. The model number lives on the data plate on the heat pump, and the code tells you the product family at a glance. This guide explains where to look, how to read the code, and why the model number matters when ordering a cooling plug.
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
Where to find the data plate
Every Vaillant heat pump carries a data plate — sometimes called a rating plate. On an aroTHERM air-source unit it is usually on the outdoor unit casing. On systems with an indoor unit, there may be a second plate on the indoor unit.
The plate is a printed or etched label listing the model code, the serial number, electrical ratings and other identifying details. If the outdoor unit is hard to reach, check any indoor unit and your installer paperwork — the same details usually appear on the commissioning record.
- On aroTHERM units, look on the outdoor unit casing.
- Check any indoor unit or hydraulic station for a second plate.
- The same details usually appear on your installer commissioning paperwork.
Reading the model code
Vaillant heat pump model codes follow a consistent pattern. The code begins with VWL for air-source heat pumps — the aroTHERM family — and VWF for certain ground-source heat pumps. On aroTHERM Plus, the number that follows gives the size: VWL 35/6 is the 3.5 kW unit, VWL 75/6 the 7 kW unit, and so on.
For cooling questions, the full code matters, not just the first few characters. Note the complete code exactly as printed, including any letters, voltage or suffix after it.
The serial number
Alongside the model code, the data plate carries a serial number unique to your unit. It is the most precise reference you can give an installer or Vaillant when confirming options such as cooling for your exact unit.
Why the model number matters for ordering
Cooling is a model-dependent option, so the model code is what confirms whether your heat pump can cool at all. It is also what an installer uses to check your installer manual’s cooling and accessories sections.
The cooling plug itself is a standard Vaillant part — 0020269259, or the identical 0020266328 — listed for the aroTHERM Plus range, VWL 35/6 to VWL 125/6. Have your model code and serial number ready before you order, and confirm with a Vaillant-approved installer if your model is not on that list.
Frequently asked questions
Where is the model number on a Vaillant heat pump?
On the data plate — a printed or etched label on the unit. On aroTHERM units it is usually on the outdoor unit casing; systems with an indoor unit may have a second plate there.
What does a code starting with VWL mean?
VWL designates a Vaillant air-source heat pump, such as the aroTHERM range. VWF designates certain ground-source units. The prefix tells you the product family.
What is the difference between the model number and the serial number?
The model number identifies the product type and variant; the serial number is unique to your individual unit. Both appear on the data plate.
I cannot reach the data plate — what now?
Check any indoor unit and your installer commissioning paperwork, which usually lists the same details. A Vaillant-approved installer can also identify the unit during a visit.
Why do I need the model number to order a cooling plug?
Cooling is a model-dependent option. The model code confirms your unit is one the plug is listed for — the aroTHERM Plus range, VWL 35/6 to 125/6 — before you spend anything.
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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