Warning 77 — Communication disturbed in twin-head pump

What does 77 mean?

Communication between the two pump heads in a twin-head pump system is disturbed or broken. The pump may automatically reset and restart once the fault is cleared.

• Power supply issue to one of the pump heads.
• Loose or damaged communication cable connecting the pump heads.
• Internal communication module fault within a pump head.

Click steps to track your progress.

1. 1

   Check that both pump heads are properly powered and connected to the main power supply.

2. 2

   Inspect any communication cables connecting the pump heads for signs of damage or loose connections.

3. 3

   If the warning persists, contact GRUNDFOS SERVICE for further diagnosis and repair.