When does it start beeping? I missed that bit.
I think these also alarm if there’s no flow through the group when the pump is running.
Trace the tank sensor probes back to the board and link it out there to rule out a wiring issue.
Whats the water level in the glass? Disconnect the flexipipe going to the manifold and see if theres flow there. The pump can run but also have no flow… if you were to disconnect the level probe the pump will cut in. Does the water rise in the glass?
