Been asked by a mate to come look at a job he has been doing,
System boiler, heating and water circuits + upstairs downstairs underfloor heating with four 2 port valves. And i think 2 or three pumps.
Now i have a good understanding of heating wiring normally but the only thing i cant work out how to do is how to feed the pumps individually to maintain the pump overrun. Being a system boiler there is already a pump in the boiler and the boiler IS pump overrun. And there is no pump terminal on the boiler, just live out to the system and switch live back in, the same as a combi. In the past i have used lower limit pipe stats to provide pump overrun as a last resort but i dont think this is ideal. So my question is how can i run these pumps separately with pump overrun?
Also if there are any plumbers out there, are these extra pumps neccesary or is the one in the boiler enough to pump all circuits at once if needed? Maybe we could get rid of the others? My mate says its an unvented system and has always thought it needs 2 valves in parallel for safety but has now been told one is enough, if anybody could spread any light on these isssues, would be a great help, thanks.
System boiler, heating and water circuits + upstairs downstairs underfloor heating with four 2 port valves. And i think 2 or three pumps.
Now i have a good understanding of heating wiring normally but the only thing i cant work out how to do is how to feed the pumps individually to maintain the pump overrun. Being a system boiler there is already a pump in the boiler and the boiler IS pump overrun. And there is no pump terminal on the boiler, just live out to the system and switch live back in, the same as a combi. In the past i have used lower limit pipe stats to provide pump overrun as a last resort but i dont think this is ideal. So my question is how can i run these pumps separately with pump overrun?
Also if there are any plumbers out there, are these extra pumps neccesary or is the one in the boiler enough to pump all circuits at once if needed? Maybe we could get rid of the others? My mate says its an unvented system and has always thought it needs 2 valves in parallel for safety but has now been told one is enough, if anybody could spread any light on these isssues, would be a great help, thanks.