How to find your Vaillant heat pump model numberWhere 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 resistor.
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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 module, there may be a second plate on the indoor unit.
The plate is a printed or etched label listing the model designation, the serial number, electrical ratings and other identifying details. If the outdoor unit is hard to reach, check any indoor module 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 module 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. The characters that follow indicate the output, variant and configuration.
For cooling questions, the family prefix and the full variant both matter. Note the complete designation exactly as printed, including any suffix, rather than just the first few characters.
The serial number
Alongside the model designation, the data plate carries a serial number unique to your unit. The serial number lets Vaillant and a Vaillant-approved installer identify the precise build of your heat pump — including the year and production batch.
For confirming the cooling option and the correct coding plug for your exact unit, the serial number is the most precise reference you can give an installer.
Why the model number matters for ordering
Cooling is a model-dependent option, so the model number 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.
When ordering a cooling resistor, the resistor itself is a standard Vaillant coding part (0020266328 / 0020269259), but your model and serial number are what confirm it is the right approach for your system. Have both ready before you order, and confirm compatibility with a Vaillant-approved installer.
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 module 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 and identifies its exact build. Both appear on the data plate.
I cannot reach the data plate — what now?
Check any indoor module 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 resistor?
Cooling is a model-dependent option. The model and serial number confirm your unit can cool and that the resistor is the right approach — check this with a Vaillant-approved installer.