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Heating performance insufficient, however heater is burning:
1. Vehicle heating system or fan adjustment wrong - prior to heater operation set vehicle heating system to warm and fan switch to stage 1 or higher (see 3.3);
2. Coolant circuit not properly bled - bleed circuit according to manufacturer’s instructions, run engine to warm up;
3. Integration in cooling system wrong - integrate heater upstream of vehicle's own heat exchanger.