combi and split zones

[buckley plumb]

got to quote for a new build small house . the boiler will be a glowworm 30 kw ultracom 2 with upstairs and down seperate heating circuits. i have a few concerns the boiler is going in the kitchen with rear piping jig and the flow above the boiler split into 2 for the zones with 2 port valves .i am worried that when the boiler is on pump overrun on htg that the internal bypass may not be good enough. i could fit an external one but it would be straight on the f and rtn connections above the boiler .i was also going to use the orange and grey wires on the zone valves to operate the boiler low voltage connections but am worried incase in the future some one accidently connects voltage to them in the wiring box.


ant

 

[diamondgas]

Don't worry If in doubt give the manufacturers a shout

 

[tamz]

I wouldn't worry about it. If some numb nut wires it wrong in the future that is their problem. Std way to wire low / no voltage stuff.
The internal bypass should be enough but above the ceiling would give a loop of over 3m so that would definitely be fine.