wiring diagram for heating

[responsegas]

hi, i have a system boiler connected to only a central heating system no hot water, i need to put a 2 port valve in to split the zones up so i was wondering if someone could shed light on the following:
how to wire
the zonal valve
how many room stats required
what sort of programmer required
thanks for reading

 

[uselessFCUK]

Search this forum for S Plan in Central Heating section.

Regards
UF

 

[Lectrician]

Either a single channel programmer if you just one time control for ALL heating, or a dual channel if you want to be able to time the zones seperately.

You should have a room stat per zone. This stat contols the associated zone valve.

You could use programmable stats (probably prefered as you do not have hot water). In this case you do not use a programmer at all.

So, constant live from FCU to COM of both room stats, the CALL from each thermostat to the corresponding zone valves brown.

The grey of each zone valve to the constant live.

The orange from each zone valve is used to fire the boiler and pump. The boiler may also need a constant live, and the pump may be wired to pump terminals in the boiler.

3 core T+E to each room stat, back to the location of the zone valves. Use a wiring centre here. Zone valves are more than likely going to be near the boiler too, so a short drop of flex from boiler to wiring centre.

 

[responsegas]

thanx for the reply, just to confirm i need 2 zone valves, 2 room stats and wire in as you said. the boiler being fitted is a system boiler no external pump so all the pcb has on it is LNE so it is switched live for demand.

 

[Taylortwocities]

Sometimes there will be LNE for the supply and another terminal (linked) that can be used to switch boiler on (from zone valves for instance)

 

[jockspark]

http://www.honeywelluk.com/article.aspx?ai=sysplansdl
try this

 

[Lectrician]

I expect the boiler will need a perment feed, and as said above a switched signal for fire.

There is often a link terminal which requires volt free switching, which you can do with the valves. Rather than placing a constant live onto the grey in the valve, place the oranges and greys across this volt free trigger.

The grey and orange are litteraly just a switch contact inside the valve which close when the valve is fully open.