Rotex HPSU compact 304 Instruction Manual page 45

Malfunction
DIP switch configured incorrectly
Hot water supply switched off (e.g. time pro-
gram is in the economy phase, parameters for
hot water supply have been set incorrectly).
Storage tank charging temperature too low.
Draw-off rate too high.
Hot water does not warm
up
Output of heat pump too low.
Water volume in system too low
Optional: Backup heater (BUH) not switched on.
Water flow too low.
Room cooling does
Cooling" turned off (e.g. switching time 
not cool
programme is in the setback phase, exterior
temperature too low).
Refrigerant compressor is not working.
System is in the operating mode "heating".
Water flow too low.
Cooling effect of
room cooling too little
Water volume in system too low.
Quantity of refrigerant in the system too low or
too high.
BA ROTEX HPSU compact 4 - 09/2013
Possible cause
8 x Faults and malfunctions
Possible solution
● Have the system checked by a ROTEX heating
technician.
● Check the operating mode setting.
● Check the request parameters.
● Increase the target hot water temperature.
● Reduce the draw-off rate, limit throughput.
● Check the switching times for room heating and hot
water supply for overlaps.
● Check the water volume and the associated primary
pressure in the expansion tank, if necessary top up
the water and reset the primary pressure.
● Have the system checked by a ROTEX heating
technician.
● Check that all stop valves of the water circuit are
completely open.
● Check that the expansion tank is defective.
● Bleed system completely.
● Using the controller (rotary switch position
whether sufficient water pressure (> 0.5 bar) is
available.
● Have the system checked by a ROTEX heating
technician.
● Check the operating mode setting.
● Check the request parameters.
● Check the setting of time a weekday in the control
system.
● Wait until minimum water temperature is reached
(15 °C). At a low water temperature the system may
use the optional backup heater (BUH) first to reach
the minimum water temperature.
● Have the system checked by a ROTEX heating
technician.
● Switch the operating mode to "Cooling".
● Check that all stop valves of the water circuit are
completely open.
● Check that the water filter is dirty.
● Check that the expansion tank is defective.
● Bleed system completely.
● Using the controller (rotary switch position
whether sufficient water pressure (> 0.5 bar) is
available.
● Have the system checked by a ROTEX heating
technician.
● Have the system checked by a ROTEX heating
technician.
● Have the coolant level checked by a ROTEX
specialist heating technician. Have him check the
system for leaks.
) check
) check
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