SUBJECT: Webasto AT 2000 ST and STC – Adjustment for Higher Altitude Operation
The practice of manually adjusting the fuel to air ratio of Webasto Air Top 200 ST and STC heaters to compensate for high altitude application has been brought to our notice.
As long-standing authorised distributors of Webasto heaters and accessories, Butler Technik are unfortunately unable to recommend this ‘on-the-fly’ and arbitrary solution.
Risks of Webasto Air to Fuel Ratio Manual Adjustment
Though we accept it is frequent practice to tweak air: fuel ratio mixture via the standard Webasto rotary controller it is very possible to mis-calculate and potentially under-fuel or over-fuel your heater.
- Under-fueling of heater at lower attitude = loss of heater output
- Over-fueling of heater at higher attitude = excessive carbon build-up, diesel fumes, early failure of heater
Adjusting fuel mixture is a workshop procedure conducted by qualified and authorised personnel. The adjustment is made to optimise the efficiency of the heater and minimise the output of CO2 emissions, not for higher altitude operation.
When higher altitude application of vehicle heaters is required, equipment designed for purpose is to be recommended. The Webasto Air Top 2000 STC RV version diesel heater kit (Part Number: 4114762RV) includes the Multi Control HD controller, making it higher altitude ready without manual adjustments. The standard Webasto Air Top 2000STC is not high altitude ready.