C plan plus... would a c plan work with 2 heating zones?

[Lozza]

Hi all

Need some tips. I have what is effectively a C plan system but want to split the heating into 2 zones. I have a 2 port 28mm valve on the hot water. Looking at the c plan wiring diagrams, would it work to have the zone valves off the thermostat circuits and the call for heat into the white cable of the 28mm valve. I'e added a picture of what I'm thinking. Any pointers?

 

[kris]

So it'd be like a C plan plus ,,,, but with an extra plus lol

 

[Lozza]

So it'd be like a C plan plus ,,,, but with an extra plus lol

Something like that? Any perceived issues with current backflow anywhere?

 

[king of pipes]

Shaun this ones for you mate , if i was installing it each zone would have its dedicated valve . kop

 

[Lozza]

Shaun this ones for you mate , if i was installing it each zone would have its dedicated valve . kop

Hi. The drawings not great I know - I've tried to show 2 valves - v1 and v2, off the respective stat circuit, with the CFH coming together to the white of the 28mm valve (allowing the boiler to fire without the pump for HW only).

 

[SavageW]

Do you want each zone for your ch to be programmed differently to each other? Or do you just want to add a zone that can be either on or off from an additional thermostat. If the latter, would be a case of hard wiring to a 2nd thermostat or easier in my opinion wiring it to a wireless thermostat.If you want each zone separately programmed I’d look at the internet/wireless/smart whatever you want to call them controls with multi zone

 

[Lozza]

Hi. Separate thermostat controlling each one, but on the same schedule. Because hw isn't pumped my issue is firing the boiler for HW and boiler with pump for CH. The diagrams on the net all show c plan but without zone valves for the CH. I guess fundamentally I'm trying to ascertain whether adding the valves between the thermostat return and the 28mm white cable would allow independent control of the heating zones.

 

[Lozza]

Do you want each zone for your ch to be programmed differently to each other? Or do you just want to add a zone that can be either on or off from an additional thermostat. If the latter, would be a case of hard wiring to a 2nd thermostat or easier in my opinion wiring it to a wireless thermostat.If you want each zone separately programmed I’d look at the internet/wireless/smart whatever you want to call them controls with multi zone

Sorry - replied as an additional comment.

 

[SavageW]

It’s hard to understand over the forum sometimes,do you want to have HW & CH on at the same time? Your current set up would be priority HW.If you want both CH zones programmed the same then you just need CH ON from programmer to go to Stat 1 & Stat 2 with the switch live from Stat 2 going to the same junction as Stat 1. Have you looked at where your additional zone valve is going to be installed

 

[Lozza]

Hi. Separate thermostat controlling each one, but on the same schedule. Because hw isn't pumped my issue is firing the boiler for HW and boiler with pump for CH. The diagrams on the net all show c plan but without zone valves for the CH. I guess fundamentally I'm trying to ascertain whether adding the valves between the thermostat return and the 28mm white cable would allow independent control of the heating zones.

It’s hard to understand over the forum sometimes,do you want to have HW & CH on at the same time? Your current set up would be priority HW.If you want both CH zones programmed the same then you just need CH ON from programmer to go to Stat 1 & Stat 2 with the switch live from Stat 2 going to the same junction as Stat 1. Have you looked at where your additional zone valve is going to be installed

Ok, so independent hw and ch. I'e 2 stats fitted. I want 2 zone valves for 2 heating zones. So I need to keep the 2 sl seperate and then take the brown to each zone valve from those. My instint then says that if I take the 2 orange CFH together, and out to the white of the 28mm hw valve, I'll be able to have heating and hot water independent of each other, and only powering the pump when the heating is on.

Tried again on the ďiagram. I'm 'adding a seperate terminal between 5 and 6 that has the SL from the zone 2 stat. Terminal 5 goes SL to zone 1 valve, Terminal '5a' goes to SL to zone 2 valve, then both valves return their Call for Heat (orange) to the terminal 9 to provide power to the boiler. If either circuit goes live the boiler fires. If the 28mm HW valve goes live then the boiler circuit is made from the permanent live, and pump is is unpowered as there is no circuit across terminal 9.

 

[ShaunCorbs]

It’s hard to understand over the forum sometimes,do you want to have HW & CH on at the same time? Your current set up would be priority HW.If you want both CH zones programmed the same then you just need CH ON from programmer to go to Stat 1 & Stat 2 with the switch live from Stat 2 going to the same junction as Stat 1. Have you looked at where your additional zone valve is going to be installed

In simple terms no separate times

But it's gravity hot water and pumped heating

Hot water work like normal but boiler is set to 65 normally

And the port valve works on the cylinder stat

Cylinder upto temp port valve closes and bypass is the heating system on gravity so one or two rads will tend to heat up

All that controls the heating is the prog and room stat no port valve for heating

Room stat turns the pump on and off

 

[ShaunCorbs]

Op your best bet is to turn the hot water into pumped and then just s plan plus it

Simpler in the long run and you will get better efficiency out of your system

If you really want to keep your system as is you will need a heat leak rad for your cylinder

And then you could zone it how ever you like

 

[Lozza]

In simple terms no separate times

But it's gravity hot water and pumped heating

Hot water work like normal but boiler is set to 65 normally

And the port valve works on the cylinder stat

Cylinder upto temp port valve closes and bypass is the heating system on gravity so one or two rads will tend to heat up

All that controls the heating is the prog and room stat no port valve for heating

Room stat turns the pump on and off

Bit is there an issue with fitting valves to the heating side?

 

[ShaunCorbs]

Bit is there an issue with fitting valves to the heating side?

Next post down from the one you quoted

 

[Lozza]

Next post down from the one you quoted

Thanks guys. So leads me to another question. I don' think that there is a heat leak rad in the system at the moment. Why would this now be needed? The boilèr (oil fired Camray 5) has 2 outlets - one of which heads to the HW and the other to CH which then splits to the upstairs and downstairs rads). Other than adding motorised valves into these 3 aspects, nothing has changed. Why would I now need a heat leak?

 

[kris]

If it was me I'd change to fully pumped and fit 3 new 2porters all wired up to separate stats , jobs a good ane,,,,,

Change to a S plan plus

http://electricalwiringdiagrams.us/...ting-system-wiring-diagram-with-schematic.png

 

[ShaunCorbs]

Thanks guys. So leads me to another question. I don' think that there is a heat leak rad in the system at the moment. Why would this now be needed? The boilèr (oil fired Camray 5) has 2 outlets - one of which heads to the HW and the other to CH which then splits to the upstairs and downstairs rads). Other than adding motorised valves into these 3 aspects, nothing has changed. Why would I now need a heat leak?

so when the hot water is upto temp and the port valve closes the boiler has nothing to heat / supply heat to atm any excess heat is going into your rads

if you add port valves to the heating side there nothing / no where for the extra heat to go

so you would require a heat leak rad