Circulation Pump (GP1) Not Starting — System water not circulating

What does GP1 Not Starting mean?

The circulation pump, which moves water through the system, is not working. This might prevent proper heating or cooling. The pump may need manual assistance to start.

• Pump is stuck or seized
• Air lock in the pump

Click steps to track your progress.

1. 1

   Shut off the F750 heat pump by setting the switch (SF1) to " ".

2. 2

   Open the service cover of the heat pump.

3. 3

   Loosen the venting screw (QM5) with a screwdriver, holding a cloth around the blade to catch any small amount of water.

4. 4

   Insert a screwdriver into the pump motor and turn it around to help it start.

5. 5

   Screw the venting screw (QM5) back in firmly.

6. 6

   Start the F750 by setting the switch (SF1) to " " and check if the circulation pump works.