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Reason
Cause:
Opening and immediately thereafter closing of the external thermostat.
Corrective action:
Controlled water flow cools down too quickly after loss of heat demand.
Controlled water flow heats up too quickly after start of heat demand.
Immediately opening and closing of the external thermostat. Check switching differential of the ON/OFF
thermostat.
Controller settings need to be changed. Be aware that the standard settings work fine for all common systems.
When anti-cycling is active, because of immediate heating or cooling of the controlled water
flow/temperature, it concerns an unconventional system.
Display message
Reason
Cause:
The water pressure in the system is too low.
Corrective action:
Check if there is no leakage in the system that causes the pressure to drop. Fix any leakage and fill the system.
Check if there is an external system pump that sucks water through the water heater, causing an under
pressure. (bad installation design).
Display message
Reason
Cause:
The supplied power does not comply with the specifications.
Corrective action:
Check if the power supply is connected correctly to the unit.
Check the voltage and frequency. (Should be Life Neutral, Gnd > 230Vac/50Hz).
Make sure there is no signal fail or voltage peaks in the power supply.
Display message
Reason
Cause:
The water flow through the unit is too low.
Corrective action:
Check functioning of the pump.
Check/open all valves that might restrict the water flow through the unit.
Check for an external system pump that influences flow through the unit.
Check if the system resistance exceeds the spare capacity of the unit pump.
Make sure the heat exchanger is clean. Heat exchanger fouling (partly blockage) will increase the resistance
causing the water flow to drop.
The controller received a new heat demand too fast after the last demand ended.
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Water pressure is too low or high.
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Bad power supply
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Difference between T2 and T1 has exceeded the blocking value which has been
set in the parameters.
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