boiler wiring

[goldie]

I have wired many 'c' 's' 'y' plans before but a friend of mine wants system zoning so he can have control over each floor on a combi boiler system (2 floors), Cant think of a simple way of doing this other than adding a relay so there isnt a back feed into the other zone, any thoughts??

 

[Knobhead]

Why not ask in the central heating section?

 

[GLENNSPARK]

but surely if you wire it "s" plan...using zone valves...so as one valve opens the other closes.....so how will there be back feed?..........

 

[GLENNSPARK]

sorry got my wires crossed here..lol

 

[GLENNSPARK]

could you not use a sprung non return valve/s to prevent back feed? on the return pipes?.....

 

[Geordie Spark]

I have wired many 'c' 's' 'y' plans before but a friend of mine wants system zoning so he can have control over each floor on a combi boiler system (2 floors), Cant think of a simple way of doing this other than adding a relay so there isnt a back feed into the other zone, any thoughts??

I did this with 3 zones - one zone per floor.

I fitted a roomstat to each floor, which operated a zone valve on each floor. Each zone valve was fitted with contacts operated by a cam on the valve spindle which closed when the zone valve was in the open postion, so, when the roomstat caused the zone valve to open (thus allowing water to pass to the radiators on that floor) the contacts on that valve closed & fired the boiler.

This means that if all the roomstats call for heat, all the zone valves will open, & all the contacts on the zone valves close so the boiler fires & all the radiators in all zones heat up.

If however, only one roomstat calls for heat only the zone valve controlled by that roomstat opens, its contacts close, the boiler fires and only the radiators in that zone will heat up.

The same applies if two roomstats call for heat - onlt the radiators in those two zones will heat up.

The valves I used were made by Honeywell, but I can't remember the part number now as it was such a long time ago.

The Roomstats I used were also made by Honeywell and were programmable so each zone could have its own independant on / off times.

Hope this helps.

 

[grimysparks80]

2 zone valves just like an s plan. not sure what will need to be done with the pipework but the wiring is just like an s plan too. remote programmable thrmostats to control each valve and a nice easy job.

 

[ezzzekiel]

agree with above pretty standard splan wiring adding in theory as many zones as you wish.

think all new installs now require 2 zone heating

 

[Guest123]

agree with above pretty standard splan wiring adding in theory as many zones as you wish.

think all new installs now require 2 zone heating

Correct, This is now a requirement under building regs.

 

[grimysparks80]

its also a requirement if you change more than one control ive been told

 

[telectrix]

all a bit over my head. my knowledge of central heating systems is limited to the fact that when a thermostat calls for heat, you get a huge gas bill.

 

[Geordie Spark]

all a bit over my head. my knowledge of central heating systems is limited to the fact that when a thermostat calls for heat, you get a huge gas bill.

Yes, but only when the gas meter is the right way round. :lipsrsealed2:

 

[Guest123]

its also a requirement if you change more than one control ive been told

The chaps on the honeywell course I attended a few weeks back attested to this also.

The eyes of every plumber on the course just rolled over and were accompanied by a groan chorus.

 

[topquark]

Just been asked to quote for a small granny annex. Kitchen and stairs at back of dbl garage with lounge, 1 bed and bath above garage. Are we seriously expecting two separate heating zones for this or is HW/CH considered enough in this respect?

 

[Guest123]

I'll see if I can rip some of the documentation off the complimentary USB drive you get as part of the course.:cyclist: