Troubleshooting for heater Thermo Top > 300.000
Heater cycles frequently between full load/part load and off

Option/
Additional Information
Possible cause Remedy
Heater's heat exchanger is hot, engine is cold Circulating pump is not delivering Check for continuity and housing ground connection at connector X18 (wire bk / br).
If continuity is not indicated, circulating pump is defective.
Replace circulating pump in accordance with directions given in the workshop manual

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