Hi,
I have a grundfos super selectric 15-60. If I have it on speed 2 everything works fine, but I get water trickling back into the feeder tank via the vent pipe. If I have the pump on speed 1 the boiler temp trips out on CH and HW. I have been into the loft, and the height of the vent pipe is 18" above the water level. The Grundfos web site has lots of info, but nothing about the vent pipe height. The original pump was a 15-50, so I'm wondering whether the plumber should have checked the vent pipe height before upgrading my pump to a bigger one (the original was noisey). Is there a standard height for domestic installations?
I have a grundfos super selectric 15-60. If I have it on speed 2 everything works fine, but I get water trickling back into the feeder tank via the vent pipe. If I have the pump on speed 1 the boiler temp trips out on CH and HW. I have been into the loft, and the height of the vent pipe is 18" above the water level. The Grundfos web site has lots of info, but nothing about the vent pipe height. The original pump was a 15-50, so I'm wondering whether the plumber should have checked the vent pipe height before upgrading my pump to a bigger one (the original was noisey). Is there a standard height for domestic installations?