UFH pump wiring

[Jondotnet]

Hey folks,

 

we have just fitted UFH in a new kitchen extension with a kit that has a valve, manifold and pump pre assembled. We have it fed from the existing boiler that now has zone valves to separate existing CH and the UFH. 
 

The UFH is controlled by a thermostat in the new kitchen that has a switched live that turns on the pump, opens the zone valve and calls the boiler to heat. 
 

It all seems to work well. 
 

the one thing that the system has that’s got me questioning how we have it wired up is that the pump also has a temperature controller that allows the pump to only come on when the feed temperature is above a certain level. Because of this I have an idea to have the pump permanently live  so it will run when ever then water in the system is warm/hot regardless of if the boiler and zone valve are switched 
 

So any thoughts from people on  whether the pump should be switched with everything else or allowed to run regardless?

 

I hope that makes sense. 
 

cheers

 

J

[Radian]

The trouble with having the pump controller permanently powered is that it will tend to run when the main system pump/valves are off. This can do odd things like drain heat out of your DHW via the indirect coil. In other words it will tend to form its own weird circulation path. I have a similar setup so ended up wiring the UFH pump control box in parallel with the main circulating pump.