newbie-ish

[amckay]

Hi all, I'll be starting work for a housing association soon after being a maintenance spark in commercial and highways. I've done domestic before but never touched on heating as it was never required for me to do so please feel free to treat me like a year1 apprentice!
S & Y plans - am I right in saying these are hard wired controllers for a combi boiler heating system and that S plan feeds the whole house and Y plan feeds top floor and ground floor seperatly but from same system?

What courses can I find in Manchester for faultfinding on these? I've tried google but to no luck.
Cheers

 

[sean_ork]

S & Y plans - am I right in saying these are hard wired controllers for a combi boiler heating system and that S plan feeds the whole house and Y plan feeds top floor and ground floor seperatly but from same system?

Nope, that's far to simplistic.

Digest the contents of the Honeywell wiring guide to give you the basic concepts, you'll see that there's an almost endless number of schematics and permutations dependant on boiler type, tank, number of zones, number of stats, number of pumps .....

Beg borrow or steal some 2/3 port valves, a room and tank stat, a pump, a wiring centre (terminal strip) and a light bulb, and practice a few different configurations - once you've got the basics fault finding should just be a logical process.

There's no need to go on a course.

Wiring Diagrams - Honeywell UK Heating Controls

 

[Richard Burns]

S plan is two separate valves for central heating and hot water.
Y plan is one three way valve for central heating and hot water.
Not applicable to combi boilers that do not need to provide a hot water storage.

 

[Leesparkykent]

With a typical two port vale you will have 5 cores. Blue neutral, green/yellow earth, brown switch live from controls, grey permanent live and orange switch live to the boiler. For a standard S-plan you will have 2x two port valves one for heating and the other valve for hot water. If you learn the colours and remember the order of switching then you cant go far wrong especially if you have a drawing in front of you. There is a sticky thread on here in the central heating section with all the standard arrangements. Would be worth printing the schematics off and keeping in a folder in the van. The order of switching goes programmer switches the feed on to the room thermostat or cylinder thermostat depending what channel is timed to go on or switched on at the programmer, thermostat if calling for heat switches the brown on the valve, valve motors round and closes the micro switch between the grey permanent live and orange switch live to boiler. Depending on the type of boiler it may have pump over run so the pump maybe directly connected to the pump live terminal in the boiler. If the boiler doesn't require/have pump over run then it will be connected together with the oranges off the valves and switch live to the boiler.

A y-plan gets a little more harder to explain but again you generally have 5 cores on the valve. Blue neutral, green/yellow earth, white switch live from room thermostat and grey hot water satisfied. The 3port valve can sit in 1 of 3 positions depending on what's being asked of it...port A closed means flow from boiler Is directed to port B which is connected to the coil in the hot water cylinder, port B closed then the flow from the boiler is directed to port A which is connected to the Flow of the radiator circuit, finally the valve can sit in the mid position letting the flow from the boiler down both port A and port B at the same time. With a Y plan you will use the hot water off terminal in the programmer and NC contact on the cylinder thermostat which you wouldn't use on a standard s-plan with spring return valves.

 

[amckay]

Thanks fellas, especially leesparkykent!
I was well off the mark lol
Could anyone direct me to a drawing I'd quite like to build a mini rig and try it out that way. Im much more better when my hands work in sync with my brain (the one upstairs before you get saucy)

 

[Leesparkykent]

Thanks fellas, especially leesparkykent!
I was well off the mark lol
Could anyone direct me to a drawing I'd quite like to build a mini rig and try it out that way. Im much more better when my hands work in sync with my brain (the one upstairs before you get saucy)

http://www.electriciansforums.co.uk...ing-schematics-central-heating-schematics.pdf

and version 16

http://www.honeywelluk.com/documents/All/pdf/Wiring Guide Issue 16.pdf

 

[tony mc]

You might find this useful a explination with the wireing next to it!

Central Heating Controls and Zoning - DIYWiki

 

[muzza1]

I used to get so peed off trying to fault find ch/hw problems, but for the last 5 years or so have quite enjoyed it after i properly sussed out how to do it!
I think once you got the valve wiring colours in your head you're virtually home and dry.