First aid for malfunctions

The advices listed here are intended as a first aid. If the measures described here do not help to eliminate the malfunction, please contact your specialist technician.

 In our FAQ, we have summarized the most frequently asked questions and the corresponding suggested solutions for you.

Error code 715/716: High pressure malfunctions


1. Check the set points of the heat pump

Ensure that the set points (hot water set point and heating curve settings) are not outside the operating limits of the heat pump. The operating limits of the unit are noted on the nameplate.

2. Are all shut-off valves open that are necessary for operating the heat pump?

Check that all necessary shut-off valves are open. Otherwise, there is no flow and the unit switches off via malfunction. If necessary, consult your installer. 3.

Is the heating system vented?

If a “gurgling” sound is heard during the operation of the circulation pump, the heating system may need to be vented. To check the function of the circulation pumps, they can be controlled individually via the heat pump controller. To do this, go to Service > Settings > Bleed system and place a check mark next to the respective pump. The selected pump runs immediately after confirmation.

ATTENTION: The individual pump designations can be found in the operating manuals.

Error code 701/702: Low pressure malfunctions in air/water heat pumps


1. Are the air intake and exhaust ducts covered, blocked or overgrown?

The heat pump air intake and exhaust vents must be unobstructed to allow the heat pump to “breathe” properly. Increased operating costs (efficiency of the heat pump deteriorates) and malfunctions can be avoided in this way.

2. Is the fan running?

If the fan is not running, the heat pump cannot remove the cold air produced and the air heat exchanger (evaporator) freezes. The result is a low pressure malfunction. To check the function of the fan, it can be controlled via the heat pump controller. To do this, go to Service > Settings > Vent system and set a check mark at Fan BOSUP. The fan runs immediately after confirmation. It runs for the duration of the set time, or can be stopped manually by removing the tick at Fan BOSUP again.

ATTENTION: The fan may not run during the EVU lockout time because the supply voltage has been switched off. 3.

3. does the outdoor temperature sensor indicate the correct temperature?

Check the plausibility of the displayed value. This should correspond to the current outdoor temperature and approximately match the heat source inlet temperature. These values can be found under Service > Information > Temperatures.

ATTENTION: The outdoor temperature sensor must be mounted on the north exterior wall of the building and protected from direct sunlight!

Establish emergency operation

This video shows how to switch heating and domestic hot water to the secondary heat generator. ATTENTION: In emergency mode, there are increased electricity costs.en

To the video