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Checking flow rate before starting the heat
pump
The flow rate through the system is high and must maintain this at all times. If the flow rate drops to low E911 will show on the screen.
If there is a separator in the system i.e a buffer, the flow rate is much easier to achieve and maintain. If there is not a separator then there will need to be extra
tests carried out.
Testing the flow in heating mode
To test the flow rate, enter the test mode by pressing the right and left buttons for 6 seconds until TEST or 7E57 appears and turn the pump on with the
power on/off button. Whilst the pump is running you will see the symbol of the house with the circle around it appear.
The unit will be running as though it was in heating mode, check the flow rate. This should be 12 L/min for the 5kW, 20L/min for the 9kW and 30L/min on
the 16kW.
If there is insufficient flow rate then the unit will never operate.
As you look at the flow meter you will be able to see the flow rate in litres per minute, the flow rate is the lower figure and not the higher.
If the flow rate in the system is not high enough then this will need attending to before continuing. Make sure that all circulation pumps are powered, remove
all air. If this doesn’t cure the issue then there is something either not right with the system or you need a bigger pump(s).
The unit won’t start if the flow rate is not high enough, once this has been rectified in heating mode then it’s time to test in hot water mode.
Press the set button to close the heating valve, 2-1 will appear on screen. Manually open the hot water valve with the lever and lock it, now check the flow
rate through the cylinder coil.
This should be 12 L/min for the 5kW, 20L/min for the 9kW and 30L/min on the 16kW.
As with heating, if there is not enough flow through the system then the unit will never start up.
To escape from this menu, press the ESC button.
Flow Test: if you don’t have a header, heat exchanger or buffer. Setting up the
bypass valve
If there is no separator in the system then you will most likely have a bypass.
To set up the bypass you will need to follow the below;
In heating mode close every TRV on all radiators and shut off all/any UFH loops, this will imitate the worst case scenario for the flow in the system. The
bypass valve will need to be adjusted to suit the required flow rates for each unit to avoid any faults, this should be 12 L/min for the 5kW, 20L/min for the
9kW and 30L/min on the 16kW.
Adjust the bypass valve so that the above flow rated are achieved, now open up all the TRV valves and reopen and closed UFH loops, then exit the service
mode by pressing ESC.
