Simple one lads..
got a house with oil fired central heating with burner and pump outside in boiler house then under the stairs is a valve,the idea being this is a two channel system one channel for hot water and one for central heating.There is a 4 core cable at the valve which goes back to the time clock,and a 4 core cable going out to the boiler from the time clock(mains supply also at time clock) so where do all connections go??its a Horstmann C21 time clock and will be fitting a 2 gang switch at the boiler house for the pump and burner.So really need to know where the connections go in the clock and 2 gang switch.
Horstmann connections only please.
TIA

crikey, i am a sparky, i can try to help you.
do you have a room stat somewhere? i see it is a combi boiler, but have you still got an immersion heater in use anywhere?
do you have any knowledge of these systems at all? it could help
What colours are the wires in the valve cable?? Blue, brown, orange , grey, if you can tell me the colours it will help,
why are you fitting a 2g switch in the boiler house?

Just check that it's an actual 4 core to the valve, and not a 3 core and earth, because you will actually need a 4 core and earth.

If so, the connections should be reasonably easy.

Now, as said above, go and find out exactly what cores you have, and their colours, and also what valve(s) you have, and the colours in it's cable, and either myself or another spark will be able to assist:thumb:

Here's a diagram of the C21 connections in case somebody sees your reply before me. Although this diagram shows only a 1 channel setup, I'm pretty sure connections 1,2 and 3 are a copy of 4, 5 and 6 for the other channel

Oh, and yeah, I'd agree with 'samcowrx', what's the 2 gang switch for:wonder:

http://www.tlc-direct.co.uk/Technical/DataSheets/Horstmann/CHANNELPLUS.gif

Cheers for the replies chaps.
Ok this is an oil central heating system with no room stats or cylinder stats,however thermostatic valves are fitted to each radiator.

There is a motorized valve fitted so there can be hot water without the rads heating.


There is a 4 core at the motorized valve which runs back to the time clock,the colours are as follows,brown,grey,black,blue no earth.

The cable colours comming out from the valve are brown,blue,grey,orange again no earth.Honeywell valve.

There is a 4 core to the outside boiler house,colours red,black,blue and earth.In the boiler house there is a pump and a oil burner.

The 2 gang switch is in the boiler house so the pump and burner can be isolated(for changing/maintenence,etc) thats all.

I need to know what connections are to be made at the time clock and the valve.

Time clock is a horstmann C21,2 channel 24 hour.

Hope this clears it up a bit.Not a combi boiler as its not gas fuelled.

Is there not a switched fused spur on the supply to the timeclock? Just use this as isolation for changing anything rather thanb mess with the wiring when you don't knowe what your doing.
The valve is a three port valve and receives signals from the the timeclock when it calls for heat to the central heating or heat for the hot water, moving the valve to a different positon for each. Isolating the timer kills the power to the valve.

Jesus this took some doodling on paper:lol1:
Right, you ready for this?

The timeclock should have a spur nearby for isolation purposes, so take a feed and neutral off this to power the timeclock.

The Valve connections are as follows:-
Grey - Permanent live
Blue - Neutral
Orange - Switched Live
Brown - Valve Activation

The switching should be done as per the drawing
http://www.jbec.co.uk/Private/Heating-Diagram-1.jpg

I can't find a propper wiring diagram for a Hortsman C21, so the above drawing is a 'best guess' but there should be a connection diagram on either the instructions, or on the back of the timeclock.

Now, since the boiler and pump come on together, all you need is a double pole switch or preferably a switched fused spur (Which are double pole anyway).

Also, ALL cables should have an earth (CPC) in!!!!! So I recommend that you replace the cable to the valve for a 5 core, and that you sleeve up one of the spare cores to the boiler in G/Y and use that as the earth.

And if another spark could just double check all of that I'm sure that 'mad555' would appreciate a second opinion:thumb:

John a very big Thank you!!!.Yes there is a fused spur beside the time clock.Cheers guys

looks about right from memory :thumb:

Adam (Plumbing and Heating engineer)

:lol1: Phew. If you check the time I posted that reply you'll see it was pretty late so my head was a little fuzzy. But if I hadn't posted it I'd be lay awake in bed thinking about it like a propper nutter:cuckoo:
John a very big Thank you!!!
Not a prob. :thumb: