Vaillant Ecotec Pro 24, ho central heating and s.30 code

[fix]

Hi I'm having problems with my Vaillant Ecotec pro 24 boiler where the hot water works fine but the central heating doesn't come on.

It hasn't been used in quite some time and when fired up the heating just won't come on, I had a radiator taken off the wall and put back on when some work was done on the wall so I bled it and the heating did seem to come on for a short while but went off again, and no matter what I try it won't work.

It used to have a crappy salus wireless thermostat so that was turned off awhile ago and I replaced it with a Timeswitch 140 which definitely used to work, I've tried to get the heating on with that in and the heating set to constant, and also tried taking it out completely, I get the same S.30 code.

I've read up about checking pin 4 for power, I assume that's on the pcb and the cover has been be opened like in the picture I've taken? I'm not the best with a multi meter but have set it to 600 and tried to check for 240v on pin 4, but it's a neutral wire so I was confused that it would even have 240v going through it? I put one connector on pin 4, and then the other on one of the live pins like pin 3 if that's correct? I get about 220v when doing that.

There is an earth wire just loose and pin 5 has no wire going to it, is that correct?

To link pins 3 and 4 together should I leave the current power wires going to them in place, and just add a loop wire?

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• fix
• 19 Oct 2013
• 1

 

[Agile]

Oh dear!

You should not have removed the cover on your boiler as thats a sealed compartment!

You measure between chassis and the terminal to be tested.

The colour of a wire's insulation has no bearing on the voltage it may be carrying. That is why you need to do measurements.

The loose green wire may be an earth wire and it may not be so until you can see the other end just put a tape round it.

Remove the two wires from terminals 3-4 and put a short wire loop between them and see if that brings on the heating.

Tony

 

[fix]

Hi thanks for the reply, surely removing the cover isn't a big deal, and engineer would remove it, and it's easy enough to put back on!

How else would you test the terminals other than removing the front?

Yes the loose wire is an earth wire which I'm guessing the installer didn't bother to tape up.

So actually remove the wires going to terminals 3 and 4 then put a loop in, rather than leaving those wires there and then adding a loop as well?

 

[RickMoore]

The cover on those boilers forms part of the combustion seal, which an engineer would be qualified to break and remake which is what makes it a big deal, the time it takes and ease of it has no real bearing.

If you know exactly what is going on at the other end of the wires connected to 3 and 4 possibly you could bridge the terminals with the wires in place, but to be safe best remove them first.

 

[fix]

Ah I see,oh dear then!! I'm guessing it does just re seal, I'm going to get some new radiators fitted soon anyway so if I have to wait until then I can get them to fit the front again, surely it should just seal back up again anyway once put back on?

All I know is people say to link points 3 and 4 together to test the central heating function, without a controller those points need to be linked for the heating to work, I can't see the wires going into 3 and 4 not needing to be connected, I suppose I'm wanting someone with specific experience with them to let me know,

 

[Agile]

How else would you test the terminals other than removing the front?

Yes the loose wire is an earth wire which I'm guessing the installer didn't bother to tape up.

You open gas sealed compartments without gas experience.

You guess what wires are by their colour!

I think you are a disaster waiting to happen!

Tony

 

[RickMoore]

To get specific experience you need to be poking about with a multi meter. Knowing what those wires are doing and knowing what they are supposed to be doing are two different things. Remove the wires then bridge.

The cover should go back on and seal correctly, but how could you be 100% sure ?

 

[RickMoore]

Btw DO NOT OPERATE THE BOILER WITH THE COVER OFF

 

[fix]

How else would you test the terminals other than removing the front?

Yes the loose wire is an earth wire which I'm guessing the installer didn't bother to tape up.

You open gas sealed compartments without gas experience.

You guess what wires are by their colour!

I think you are a disaster waiting to happen!

Tony

I think that's a little harsh, I've opened the compartment without knowing it was sealed just to take a look, how else is it possible to test the terminals?

I haven't guessed about the wiring by it's colour I just took and assumption that brown would be live and blue would be negative, and before doing anything with the wiring I've asked for advice, as I didn't want to swap round wiring until I had advice from people in the know, all I did was put a multimeter on the terminals.

 

[fix]

To get specific experience you need to be poking about with a multi meter. Knowing what those wires are doing and knowing what they are supposed to be doing are two different things. Remove the wires then bridge.

The cover should go back on and seal correctly, but how could you be 100% sure ?

Sorry no when I mean specific experience I mean someone who has been through this before, I have read up on here of people advising about those terminals 3 and 4 from their own experience.

I'll remove them and bridge 3/4 to see what happens, and yes you're right even if I fixed the boiler I would get the cover checked when I get my radiators fitted shortly

 

[RickMoore]

Erm well both myself and tony are heating engineers, so I would have thought that was experience enough tbh.

 

[fix]

Sorry I wasn't doubting your abilities in the slightest I just hoped someone who had specific knowledge of my boiler would be able to say yes those wires are definitely needed when a loop is made or no they're not that's all, I would be stuck without your advice so it's very much appreciated!!

disconnect them and make a loop tomorrow and see if it works, thanks for the help both of you

 

[fix]

Well it's good news, the boiler works when linking 3 and 4 together! So does that just mean the timeswitch I had fitted is faulty? Thanks

 

[RickMoore]

Either faulty or incorrectly wired.

 

[fix]

It can't be incorrectly wired it just plugs straight in and it worked before so I'll take it that it's faulty then thanks