Sundial C plan Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[Marinl]

Have purchasd a Honeywell wiring centre and intend to use it to wire C plan.

My system is a typical pumped CH and gravity HW with 2 modifications. I have a 2 port valve in the CH flow (to close Ch pipes in summer) and a pump in the Hw return (had problems with air locks in HW system)

I am assuming that the 2 port valve in th CH flow is wired to the HTG Valve on the wiring centre and the HW pump wired with the auxilliary from the HW valve.

My question is: Do the links to be cut alter from instructions if the above additions have been made?

[plumbbob]

The Honeywell wiring centre is only designed to be used with fully pumped "Y" and "S" plans. "C" plans can be catered for if the only inclusion is a valve in the gravity system.

As you have other devises installed, your system is effectively none of the above therefore I suspect the centre will not work at all.



To be certain, I would need a lot more information about your system such as boiler and timer type, is a room and tank stat fitted? How many wires does the 2 port valve have (there are different types). You mention a pump in the DHW circuit. Does this mean there is one in the heating too?

[Marinl]

hi plumbbob
Some more info about my system:

Boiler: Ideal mexico with 4 tappings
Boiler timer: Horstmann 425 Diadem
Room Stat: Drayton+3
CH system: Pumped with 2 port valve in line to prevent HW syphoning during CH shut down in summer. this opens when pump energised
HW system: Originally pure gravity, but a pump has been introdused on return to cure air lock problem

Intend to install cylinder stat and 2 port valve with 6 wire, on HW return. Was intending to wire, via wiring centre, for HW pump to start when HW valve opens and stop when it closes.
The final result will hopefully allow for seperate timimgs for the CH and HW via Horstmann such that HW 2 per day, CH 24hrs. Timings and teperatures from room stat.

Does this make sense?

[Marinl]

Sorry plumbbob slight change to the info I gave:

Due to the pipe work being 28mm leaving the boiler then reducing to 22mm to my cyclinder the 2 port valve will be 22m and have 5 connections