Increasing the effective altitude of a Webasto heater

There are no HAK (High Altitude Kits) available for Webasto or Espar heaters (except for first-generation Espar models).

The only way to increase a heater’s altitude tolerance is to have a mechanic manually adjust the air–fuel mixture. However, this is not recommended by Webasto or Espar, as it voids the warranty and can lead to unexpected heater issues.