Installation guide

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VMBME102

14.7 Operational problem – Heating comfort

Problem – Too cold

Cause Troubleshooting Remedy

1. The heat pump’s control computer is not

set/adjusted to the customer’s requirements/

wishes.

Check the ROOM and CURVE and MAX set-

tings.

Adjust incorrect values in the heat pump’s

control computer.

ROOM = Desired indoor temperature

CURVE = Should be set so that the desired

indoor temperature (ROOM) is maintained

regardless of the outdoor temperature.

MAX = Highest set-point value on the supply

pipe regardless of the outdoor temperature.

2. Incorrect operating mode set in the heat

pump’s control computer.

Check which operating mode is set. If the incorrect operating mode is set,

change to the desired operating mode.

3. Sensor fault, OUTDOOR/ROOM/SUPPLY

PIPE/RETURN PIPE.

Check what the relevant sensor shows, is it a

plausible/actual value?

Measure the resistance of the sensor, check

against the ohm table in the “Measurement

points” section.

If the sensor is defective, replace it.

4. The 3-way valve has jammed in hot water

mode.

1. Check the function of the 3-way valve

motor by test running it manually. If the

motor does not shift mode during manual

test operation, check that there is voltage to

the motor, see wiring diagram.

2. Detach the motor and test closing and

opening of the valve by pressing the control

arm.

1. Is the motor being supplied with voltage

according to the wiring diagram in both

operating instances?

MANUAL TEST – VXV HOT WATER

0=Radiator mode, arm out from valve.

1=Hot water mode, arm positioned towards

the valve.

If there is voltage to the motor but the arm

does not shift mode, replace it.

2. Take out and clean the jammed insert, or

replace with a new insert.

5. Defective electric heating element. Use a buzzer and check if all coils in the elec-

tric heating element are intact.

If the electric heating element is defective,

replace it.

6. The heat pump has stopped on HIGH

RETURN.

• Check what the MAX RETURN value is set at

in the heat pump’s control computer. It must

be adjusted to the unit’s maximum supply

temperature and the system’s delta tem-

perature so that it does not cut at too high a

return temperature when the highest supply

temperature is transmitted.

• Check what the return pipe sensor shows,

is it a plausible/actual value? If not, take

a resistance reading from the sensors

and check against the ohm table in the

“Measurement points” section.

If the MAX RETURN value is not adjusted for

the system according to the troubleshooting

window, adjust it.

If the sensor is defective, replace it.

7. Heat production is stopped by the

HYSTERESIS function.

If the flow temperature rises as soon as heat

production is stopped by HYSTERESIS before

INTEGRAL reaches 0, there may be heating

deficit in the house.

• Check if heat production stops because

the hysteresis value is set too low? (See the

installation instructions for factory setting.)

• Check if heat production stops because

thermostats/valves in the heating system are

closed or partially closed?

• Check if heat production stops because the

heating system is under dimensioned?

• Try increasing the hysteresis value until the

heat pump stops on INTEGRAL instead.

• Open thermostats/valves in the heating

system and check that the heat pump stops

on INTEGRAL.

• If the heating system is deemed to be

under dimensioned, the system must be

extended (increase the heat emitting sur-

face).

8. The auxiliary heater is not permitted to cut

in with sufficient output.

Value set too low on MAXSTEP.

MAXSTEP 1 = 3 kW

MAXSTEP 2 = 6 kW

MAXSTEP 3 = 9 kW

MAXSTEP 4 = 12 kW

MAXSTEP 5 = 15 kW

Check the set value on MAXSTEP in the heat