Open vent "pumping" over

[petethefeat]

I have just replaced a Gledhill systerm mate 2000 with a Boilermate BP, the heating (and hot water) systems are open vented. I have a small amount of water discharging from the heating vent pipe when the pump stops! I believe the pipe work configuration is correct. Does anyone know if this will cause a problem?

 

[migoplumber]

gledhill systemmates are an ingenious bit of kit, i dont like them personally, but they are quite clever.
the boiler mate i dont know.

all i would suggest, if you are replacing the systemate. label all pipework, remove unit. treat it as a new installation with existing pipework.

shaun