Central heating problem

[Rich D]

In seriousness - looks like it uses a "wall plate" - im assuming that the whole thing pulls off the wall exposing a wall plate with the terminals

[Northy]

I'll have a go.

How do I frig the 'mid position valve' in the airing cupboard for some heat?

G

[Rich D]

No pilot light = no heat regardless of the position of that valve. Your timeclock is an electronic one. Could well be that if theres no output from it

[ashleyb4]

Screw on the bottom?

A

[Rich D]

Can you hear the switch within the timer "clicking" when you switch from off/all day/twice ? If not i reckon that you could be onto the problem. You can bridge the wiring to get you going if so

[JCJC]

Originally Posted by Northy

Quick update, I got brave with the multimeter. There is not 240V on the first mains block inside the unit, so I'm gonna take the timer box to bits, any suggestions?

G

U's really brave, then you need the 10 way connector as per page 30, assuming the original fitter used one, all neutrals are on pin 2, live goes to clock/timer/programmer, call for heat/switches to ON, live goes to room thermostat on heating side and clyinder thermostat on hot water side, back via 10 way connector to diverter valve ( you may have 1 three way or 2 single valves) the live opens the valve. this is the tricky bit - when the valve is fully open it trips a micro switch in the valve, the micro switch has a permanent live which goes to the boiler & pump via the 10 way connector and switches both to on/run, as posted above there is a sliding lever on the side of the valve that manually opens and trips the micro switch to on. So the live is connected by a series of switches, they all have to be in ON mode to open the valve, when the valve is open a live is allowed to the boiler, the boiler cannot run if the valve is closed, keeps you safe.
Of course the fitter may not have used this system, may have used other positions - anything
Mostly I think you need a qualified person, get to bed with a hottie bottie

[Charlie Ware]

Charlie's Dad

Graham, STOP NOW.

I'm an electrican and an M&E engineer and deal with these things all day long.

If you not careful this will end in tears. Apologies to all those are being helpful but playing with gas and electric is best not done.

Chances are it's something simple like the pilot light's just gone out, could be a coincidence that the neon has gone as well or you never noticed before and it's never even been on.
Try the pilot light procedure again but hold in the ignition button for longer before and about 20 seconds after and make sure you can see where the pilot light should be lit


The electric shouldn't have turned itself off or blown a fuse for no reason, once the heating has been off all summer the pilot light is prone to going out until it has been on for a month or so.

If you 100% sure it is the electric turn off the breaker (then prove it's off) before working on it or if not confident call out the sparky

No one can really diagnose this online it could almost be anything.



Steve

[Northy]

I'm an engineer too

Well I've had the timer switch to bits, nothing obvious there.

When you cycle through from 'off' to 'on' the relays click.

So I'm gonna leave it for tonight and call a man in. Not sure the baby will cope well with a hot water bottle though

I'm off to bed, I've got suspected Swine Flu

Thanks everyone.

G

[Rich D]

I wouldn't of advised if i didn't already know he was an Electronics boff Steve but ultimately you are right.

Hope its not too expensive, let us know what it was

[JCJC]

Very, very good advice, but I also know hes a capable boy, if you look at the boiler wiring the power will only be at the boiler connector when all the other parts of the circuit are calling for heat if it has been wired to the book, but having been in the building industry a few to many years ......................

[Northy]

Thanks guys,

Right, back on this as I'm cold this morning and still feel like shit.

The Timer switch clicks when you cycle between on and off, so the relays are clicking in, so could it be the thermostat? It clicks, but that's just the bimetalic switch? It might not actually be switching power through? Does it switch the mains through?

Do I just have to replace things with new bits?

[BRS]

Firstly I'm not an expert, what I would do is test for power out the timer box if youre not getting any power out then just hot wire into the boiler for now from the supply to see if you can get the thing fired up (establish it should be a 240v feed going in from the timer box).

If you can get it fired up that way you can at least get your wallet warmed up for when the Heating Engineer arrives

[bodgit]

who is your supplier. If its BG and you have duel fuel they will come out and fix it for £99 inc parts. They are stopping this soon and asking £2 a month but will still only charge £99 fixed fee for any boiler electrical or drain problems.

[Northy]

Right, who knows about wiring for central heating?

I've taken the back box off for the timer switches, and I have:

mains feed in - Red, black and earth
cable to boiler - Brown, Blue and earth
cable to thermostat - Red, Blue,Yellow + Earth
mystery cable - red,black and earth

I have no idea where this mystery cable goes but think it could be part of the problem. It goes into the wall and up.

The neutral of it is bundled into all the other neutrals.
The earth is to all other earths - obviously
The live goes into a bit of chocolate block to connect to the live for the boiler. As the boiler isn't getting power, then whatever is on the other end of this cable might be at fault.

Had plumber round, he says it's electrical so can't touch it.

G

[MikePimlott]

up to a cylinder stat or frost stat???

[Northy]

That's what I'm thinking Mike, I'm now in the airing cupboard

G

[JCJC]

See my post from last night, live is a series of switches, runs via timer, roomstat to diverter valve, stop there, timer must be on, stat must be on this is all possibly 240v, with timer on & stat on the valve should open, when open it also trips a microswitch with its own permanent live feed, the live should go from the microswitch to the boiler & pump switching them on.

The diverter valve micro switch & motor are items you will reconise, they often fail, is there a 10 way junction box where all these cables connect in to each other.

Added: if you are in the airing cupboard with the cly stat and a screwdriver/tester tningy with a neon in the handle you should be able to carefully check the IN terminal & the OUT terminal and move the stat to insure its working.

[Northy]

JCJC, I think we're onto something now.

The only way I can get the boiler to run is turn the room thermostat up so that clicks on, then turn the tank thermostat so that clicks on.

I can turn the boiler on or off by the tank thermostat but not the room thermostat. Does that point to anything at fault?

I'm a bit lost by your description, but yes, there is a junction box in the airing cupboard with loads of wires in! Two wires coming in from downstairs (timer swich and room stat?) and wires going to the tank stat, pump anf the 3 way valve thingy.

G

[AndrewCaunt]

Told you that three way thingy can seize up opperate it manuley it might be that thanks Andrew

[Northy]

How do you manually dance it?

Good news is I don't seem to have swine flu, am feeling better and have learnt a bit about heating systems today

G