help with central heating s plan plus newbie

[cairns]

Hi there, I'm currently in my 4th year, been given a job which includes wiring up the heating. Don't have any real experience in this area soo help would be much appreciated.
2 combi boilers feeding
2 seperate heating zones with rads, a underfloor heating zone and a hot water circuit which is a megaflow.
Bit confused with the wiring up of the megaflow
I'm thinking running a radial 20amp to from d/b to isolator then into the megaflow directly, then connect the hot water on channel on the programmer directly to the brown on the two port zone valve for the hot water circuit. Is that right?

Also the pump for the underfloor heating would i be right in thinking it should go with the brown of the underfloor heating zone valve as opposed to the orange because it would be running anytime any other channel was calling for heat?

many thanks

 

[jaydee81]

your mega flow cylinder will have a immersion heater element and a cylinder stat basically hot water on from programmer to common on cylinder stat normally open contact to brown of the valve as for your underfloor heating there is normally a wiring centre supplied with the kit which does all the switching if not you need to separate ufh pump using a relay

 

[cairns]

ok thanks soo there will be two cables coming from the megafow a live supply and a control cable right. Yeah its not a multiple zone manifold its just a single one with no actuators, don't see why it needs a relay if i put the pump brown in with the brown of the zone valve for the hot water circuit it will only run when the hot water is turned on? thanks

 

[jaydee81]

yes a 16 amp dedicated supply to immersion heater element and cylinder stat wiring not sure on your set up but guess there is a pump for heating and hot water and a separate under floor heating pump its the under floor heating pump that needs a relay because the zone valve needs to be open before the pump starts or else its pumping nowhere

 

[cairns]

how do i wire the relay never done it before :elvis: ? thanks

 

[jaydee81]

check out honeywell u plan wiring diagram all will become clear [honeywell wiring guide issue 16 pdf]