Ebersparcher d4 thermostat not controlling

Minchsailor

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Heater starts up fine, runs normally at boost, then reduces speed/heat a bit after about 10 mins, then as the cabin gets warmer it does not resduce heat any more. Was OK at start of season. No fault codes shown. Voltages OK. Wiring harness OK. Tried at various thermostat settings (including a very low temperature when it shouldn' have run at all, but it did.). Suggestions for doing checks? How do I check the themostat output (it is about 1.8Kohm)? Not on boat at present, have a simple multimeter for doing checks.
 

rob2

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Can you give more detail as to what controller you're using? Is the heater air drawn in form outside or recirculated? Regardless of which controller you're using, if the air is drawn in from outside and for some reason the control has reverted to the sensor in the intake, it will not be aware of the cabin temperature. Of course, it could be that the sensor, a temperature dependant resistor, has gone out of circuit.

Rob.
 

Minchsailor

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The heater is not recirculating. The thermosat is the cabin temperture. I have checked continuity up to the connector to the CPU; so I guess the CPU is detecting the room thermostat and not using the incoming air temperature, but i don't know how to check this. The controller is the 7 day with diagnostics 701.10.003
 

pcatterall

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The heater is not recirculating. The thermosat is the cabin temperture. I have checked continuity up to the connector to the CPU; so I guess the CPU is detecting the room thermostat and not using the incoming air temperature, but i don't know how to check this. The controller is the 7 day with diagnostics 701.10.003

Cant remember the wiring of the 701 but commonly the temp control on the timers is via the red/slate and the brown/white leads. resistance range from max to min was in the order of 2.2 to 1.7 ohms. If there is no variation from high to low then there is a problem with the timer I guess.
 
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