# How to activate cooling on a Vaillant aroTHERM heat pump

URL: https://www.vheatc.site/how-to-activate-cooling-on-an-arotherm-heat-pump
Canonical-URL: https://www.vheatc.site/how-to-activate-cooling-on-an-arotherm-heat-pump
Updated: 2026-05-22
Language: en-GB

The two-part process for enabling active cooling on a Vaillant aroTHERM: fitting the coding resistor and enabling cooling in the installer menu.

Activating cooling on a Vaillant aroTHERM heat pump is a two-part job done
by a Vaillant-approved installer.

- Step 1: confirm a cooling-capable model and cooling-suitable emitters.
- Step 2: fit the coding resistor (0020266328 / 0020269259).
- Step 3: enable the cooling function in the installer menu.
- Step 4: commission and hand over the controls.
- The resistor alone does not switch cooling on.
- Cooling needs fan coils, not ordinary radiators.
- Resistor price: GBP 47.50. Genuine OEM, factory packaging.

Shop: https://www.vheatc.site/