Central heating wiring fault. In need of some help please.

[mutley racers]

Hi, i have just moved into a new home. It had a 3 port valve which only seemed to work for central heating when you had hot water. so you always had to have hot water even with the heating. So i decided to buy a new valve and wire it in. Then when i took the head off the 6 way round junction box, the orange and grey wire were not connected to any where. just cut and left.

So i bought one of those 10 way honeywell junction boxes and followed the diagram on there.

I have had lots of different problems with it.

1st i can get hot water, nothing else. Then i can get hot water and central heating. No mid position.

Now i can have hot water and mid position but it wont give me central heating on its own.

The valve moves, stat calls for heat but, the pump doesnt seem to kick in.

Am thinking that its got something to do with the wiring in the programmer. The programmer is a potterton e3002. Its not wired the way it says on the back. It basically has a link from the live to number 5. And then a live to 3and4. Thats it.

Can anyone here give me some advice? The wiring from the programmer goes into 2 other wiring centres in the kitchen before entering the airing cupboard and am lost with using a multimeter.

Also, does anyone know of any good causes you can go on to learn the wiring and fault finding of central heating systems? Or is this a touchy subject as were not allowed to work on them unless part p.

I have signed up for the one day course with Honeywell.

Hopefully this will do me some good.

Thanks guys.

A bit long winded i know

 

[tamz]

You will need to get another wire from the programmer HW off (terminal 1 on ep3002) to the grey wire from the valve.
The programmer needs the link from L-5 as it has no internal switching.

You will learn a lot from the honeywell course.

 

[mutley racers]

wow, fast response. Thanks tamz. Are heating engineers actually allowed to work on the electrics or do we have to get an electrician?

What are your views

 

[mutley racers]

i see on the back plate of the programmer, there is a neutral wire thats all curled up. And about 2 metres away, in a wiring centre where the wires lead from the programmer, there is another neutral all curled up and not connected to anything. Is it possible to check that they are the same wire? I know a continuity test would do it, but my multimeter does not extend to that distance to do it. If this is not being used, can i put a block connector on this and connect that to terminal one and to the grey in the wiring centre? Would i need to wrap it in red tape?

Cheers

I love this site!!

 

[tamz]

It will be an unused wire from a 3 core (red yellow blue + e). The red and yellow will have been used from hw and ch on (3 and 4).
Put the power off and connect it with another wire say the yellow. At the other box test for continuity between the blue and yellow.
Always best to mark it with a red or brown sleeve or tape just so you know.

I do my own as most electricians don't know shyt about heating.

 

[dontknowitall]

There was a thread on here 2-3 days ago with links which you might find useful - and loads of input from Tamz too if memory serves me correctly!

If your multimeter has a bleep test on it then you can test for a current. For example on a room stat it won't bleep if not calling for heat but will bleep when the room stat is turned up and calling for heat. If you follow these wires all the way up to the wiring centre you can check to see if they're in the right place.

Ditto the hot water cylinder stat.

And so on ...

It takes ages (unless you're called Tamz!) but if you fix it you'll get quite a sense of satisfaction.

 

[quality]

How do you know its a neutral don`t judge by colour . I always disconnect from the supply and test through earth for continuity but as tamz said don`t get an electrician as most have not a clue when it comes to heating controls

 

[mutley racers]

Thanks chaps. All my wires are in 2 core and earth. 3 of them in the programmer. So all brown wire from 3and4. I just tried my multimeter to see if the leads would stretch. they did, so on continuity i got a bleep. So shall connect to this tomorrow and run cable to hw off.

Dontknowitall, when you say you can check to see if the roomstat is working by a bleep, what setting do you put the multimeter on/

Cheers mate

 

[tamz]

I've been wiring heating for over 30 years so it is second nature.
Never take any wire colour to be as you would think in heating. Heating is all about switch wires and you just use the colours you have. They should be sleeved but you won't see many that are.

I'll post this link again as it is a good one. It will help you follow what switches what in Y and S plans.
Honeywell Y-Plan Explanation

 

[tamz]

You will have 2 spare blue wires then or whoever wired it has connected 2 neutrals.
Remember you also need a 3 core to the cylinder stat as it needs to feed from the sat terminal to the grey from the valve too.

Follow the drawings in the above link.

 

[dontknowitall]

... they did, so on continuity i got a bleep. So shall connect to this tomorrow and run cable to hw off.

Dontknowitall, when you say you can check to see if the roomstat is working by a bleep, what setting do you put the multimeter on/

Cheers mate

The continuity test if that's the one that produced the bleep for you.

In the room stat there are two wires (number 1 and 3 I think) and you put the multimeter on these. When stat is turned down (not calling) no continuity and when turned up (calling) there is continuity.

Please, someone, do shout if I've got this wrong!!

 

[quality]

be aware that most if not all meters will beep (as most folk say) with a resistance of upto 200 ohms which can easily track through electronic programmers and such

 

[mutley racers]

Thanks guys. I really appreciate your help.

I dont know what it is but i just cant seem to work out these switch lives and that. All really confuses me.

i have like 4 different books on them and still cant seem to work it out.

 

[stevetheplumber]

sometimes a neon is just as easy to test a stat if theres juice both side its on one side it off but you do need a meter for testing any neutrals

 

[mutley racers]

Have any of you guys got this book or heard of it?
Domestic Central Heating Wiring Systems and Controls [Hardcover]

Raymond Ward (Author)

iF SO, IS IT ANY GOOD?

it does not seem to mention anything about fault finding. Which is really what i need to learn

 

[stevetheplumber]

funny ive been wiring systems for thirty years and still have to look at the diagram for y plan bit of a mental blockge i think
s plan give me as many zones as you want wired or radio stats and ill wire it without thinking strange how the brain works

 

[tamz]

Just follow the wires and see where they go.
S plan is easiest to understand.
CH on through stat to brown of heating valve motor moves and makes microswitch sending power to pump and boiler.
HW side the same.

Y plan is a bit different as there are 2 microswitches and a resister and diode inside the valve so it is harder to explain as it does different things as it is fed through the valve. It is always harder to get your head around these.

When checking voltages on a mid position you should have

Hw only on, 230v on orange wire, 0v on grey and white
HW and CH, 230v on orange and white and a reduced voltage on the grey.
CH only, 230v on orange, grey and white
Off 230v on grey

I'll need to think a bit to properly explain this so i may miss something but i'll give it a go.

Valve resting normally at HW side. Turn on HW power goes through the cyl stat and fires the boiler/pump. There will be power on the orange to the valve but this is doing nothing.
Now turn on CH along with HW.
Power is applied through the roomstat to the white of the valve which advances the motor to mid position and makes microswitch 1. This cuts the power to the motor and sends power through the resister and diode which gives the motor a reduced voltage so it cannot advance further but still enough to hold it where it is.
HW gets up to temp and cyl stat switches to sat sending power to the grey wire. This applies 230v to the motor and it now advances to its farthest position and as it does so, momentarily kills the supply to the pump/boiler on the way until it reaches its furthest position when microswitch 2 makes and the 230v is restored to the pump/boiler through the orange wire.
Still with me?
Now say it remains this way and the programmer turns off the CH and HW. The valve will remain in its furthest position as the motor is still being powered from the HW off on the programmer.
If the programmer next switches on HW first it will go back to the start but if it switches CH and HW the pump and boiler will initially be fed from both the
room and cylinder stats but the power to the motor will be cut, it will move back to mid position the microswitch will make and the motor will hold in mid position.
I think that is right but feel free to correct anything i've missed.
Bit more complicated but draw it and follow what i am saying and you will get the idea.

 

[Dannypipe]

If you get stuck, call Honeywell tech line. They're helpful.

 

[mutley racers]

Hey tamz, thats awesome. I have fixed the valve now. Just connected a wire into the spare from hw off to the grey in the wiring center. All is working fine now. Am chuffed. I kind of knew there was something wrong with the wiring on the programmer but could not understand the drawing on the back of it.

I have been going through all the honeywell diagrams from the honeywell guide and it is kind of making sense.

What you have just written above, is so beneficial. I really appreciate it.

Its mad as i am just finishing my nvq 3 and they do not teach us anything about wiring. Quite scary actually. Am lucky that i have a house to play around with the controls.

This forum really does help a lot

 

[mutley racers]

So to test the voltages, do i just disconnect the valve motors from the wiring centre and test them using the neutral from the pump?

I know this is basic stuff but my boss seemed to just crack on with his testing and not explain it. Or just get me to do the installs and none of the electrical fault finding.

I have only this week bought myself a multimeter and am trying to get to grips with this.

 

[tamz]

Just test it all in position preferably against an earth.
They won't teach you anything about wiring heating in collages and they barely mention it to electricians.
Beats me how young ones are supposed to learn it but you will pick it up.

 

[dontknowitall]

You can try it at home (without the pressure of course).

If your wiring centre is in the airing cupboard you can turn the hot water cylinder stat up and down and see what happens with the wires/multimeter (mind the voltage though!)

Then once you've found the connections for the hot water cylinder, look for another component (e.g. the pump).

It might not teach you loads (maybe it will?) but at least you won't be frightened of looking at a customer's wiring centre. Bear in mind that if there's a wiring fault it's going to take a while to sort out (even if you are reasonably experienced).

 

[quality]

The difference is that if it has worked correctly previous to the fault then its obviously a component fault if it has never worked proper then disconnect every thing and wire it correctly

 

[mutley racers]

keep em coming folks. This is really good. i was feeling a bit stressed a couple of days ago. But now, it is all starting to make sense. i have pretty much learnt the the s and y plans. The diagrams any way. so should be able to to know what goes where in a wiring centre. The place where i live though, the wiring goes from the programmer, to a wiring centre near the boiler, then into another wiring centre 30cms away and then through the kitchen ceiling, along the loft and down into the airing cupboard into a little junction box. And the pump wire runs straight to the boiler, and i think some how, into one of those wiring centres and back to the airing cupboard.

So i did not know if this was the live from the boiler or the live from the pump that should go into my wiring centre. As there was only this cable left. I assumed it was the pump and wired it to the orange and it all works great.

how can you test if it is the pump?

 

[mutley racers]

Hi tamz, i was recently in edinburgh for for a weeks holiday and i noticed on the buildings there they had these 22mm copper pipes on the external walls which came from inside and went vertical and then had a bend pulled more than 90degrees.

Is this how you guys do your blow off?

 

[Bartdude]

Hi tamz, i was recently in edinburgh for for a weeks holiday and i noticed on the buildings there they had these 22mm copper pipes on the external walls which came from inside and went vertical and then had a bend pulled more than 90degrees.

Is this how you guys do your blow off?

They don't even like giving water away up there

 

[tamz]

Hi tamz, i was recently in edinburgh for for a weeks holiday and i noticed on the buildings there they had these 22mm copper pipes on the external walls which came from inside and went vertical and then had a bend pulled more than 90degrees.

Is this how you guys do your blow off?

No
Those are expansion pipes on the old tenement flats.
Each flat had its own lead lined cold water tank, usually above a lowered part of the bathroom ceiling in the middle of the flat. There was usually a dublo tank (narrow twin cylinder) in an alcove next to the sitting room fireplace. As the hot water was het by coal via a direct back boiler you weren't allowed to terminate the expansion above the tank because they boiled over every other day (it was too far away and no road to it anyway) so the expansion was taken up to high level and out through the wall. A loop of pipe was then taken up against the wall about a foot or so then dropped. These pipes are often onto the main pavements as most don't have front gardens. The water just ran down the wall.
And they worry about a pyssy wee prv pipe nowadays

how can you test if it is the pump?

If you can't trace it pull the wire out and see if it stops.

They don't even like giving water away up there

We've got loads of the stuff. Lovely and soft too. None of that limescale or filtered sewage rubbish up here

 

[mutley racers]

oh i see. Now that makes sense. Thanks. i have been wondering what they were for a long time.

Yes its funny now how the regs are with blow offs and discharge locations from unvented.

Quite silly really.