My piped water central heating system is fired by a wall mounted Baxi gas burner. I want to replace the timer switch that controls when it comes on/off. BUT - I find TWO supply cables (3 core) disappearing into the burner innards. One cable goes pack to the timer. The other goes to a permanent live supply (can only be switched off back at the fuse box).
Is this a botched wiring job or is there a reason for two supplies?
Ger
Why would you describe it as botched because you don't know how it works? I would leave the DIY to someone that knows exactly what they are doing. You might not get on too well with electric AND gas in such a small area. Have all the emergency numbers nearby.
In message , ger writes
Well, in light of the fact that you've not really given much useful info
probably one is powering the timer, one is switching the boiler
Thank you for your response Rob. I felt that any wiring that goes directly to an appliance, without an isolation switch, is botched? Am I wrong?
I would also please appreciate an answer to my question - do gas burners typically require two electrical feeds? And if so, why?
The timer is remote from the burner so I should be safe from gas. But your tip is appreciated, I'll have the emergency numbers nearby.
Ger
Thanks Geoff. I has assumed that the only supply to the burner would be switched on/of via the timer. I was hoping to be told that for some reason, gas burners require two supplies. Perhaps one from the timer to start/stop the burner, and one for the water pump to operate independently. Or for some other purpose, unknown to me.
Ger
In message , ger writes
Most modern boilers have a permanent live and a switched live, the SWL being to tell the boiler to fire up
Mine has three "feeds":- mains in, pump out, timer out.
There should be one and only one source of power to the system, and that must be cabable of being isolated by a gap of at least 3mm in both live and neutral poles. (I put it like that because a plug and socket arrangement does comply in that respect, though it's not strictly kosher.)
If the supply can only be switched at the fuse box then it's wrong. Whether you label that a bodge is up to you.
The boiler (you don't say what model) may require a permanent live supply (e.g. so that it can control the pump) and may be intended to be connected to an external thermostat and possibly also time switch etc - depending on model and age.
Modern(ish) boiler will feature a pump overrun capability and hence need a permanent live supply as well as the switched live from the thermostat/programmer. The programmer may also require its own supply.
Thanks to all. Looks like the permanent live supply is for the pump. The timer is for the burner. BTW - it's a BAXI burner. Ger
Yes you said that in the original post. I don't suppose you'd like to share with us which, of dozens of models of boiler Baxi have produced over the last half-century or so, it is?
And they're called boilers: the burner is part of the boiler.
Yes you said that in the original post. I don't suppose you'd like to share with us which, of dozens of models of boiler Baxi have produced over the last half-century or so, it is?
And they're called boilers: the burner is part of the boiler.
John, there's a crabbiness in the tone of your response. I was doing my best to provide as much information as I thought necessary. If I failed in that, I apologise. I will refer to them as boilers in future. I am the wiser. I wasn't aware that Baxi have been making boilers for 50 years. I am now. But if you expert members of the group want to encourage us learners, it would help if you adopted a somewhat more sympathetic attitude. I moderate some forums in my own area of expertise. If I saw a response like yours above I would reprimand the poster. Ger
In message , ger writes
I think that gets a FRO from those who know
I (being normally more abrasive), held back from saying exactly the same as John did
You didn't have the intelligence to say what boiler or what timer
a bit like saying I have a ford with a radio in it what colour wires go to the speakers
wanker ...
You can be excused that.
But it isn't rocket science to realise that you gave far too little information about the boiler and the problem itself.
This is usenet - no moderation. People can to be a little more abrasive, and may even appear to be downright rude. However uk.d-i-y is actually chock full of helpful people - if you're willing to put in the effort, and shrug off the reprimands you'll get if you're appearing to be a numpty, you'll find it's actually a very worthwhile resource. It's not the tone of what's said which is important here, it's the content.
Treat is as a pub where there are regulars who've been there for years - you wouldn't wander into the room of strangers and tell them off, and you should be careful not to do it here.
Re the original problem - if you've got questions about this sort of thing, you need to give as much information as possible - eg boiler model number, in this case.
clive
Ger don't get to bent out of shape over this, I am sure John was not really being crabby, but was perhaps reacting to what seemed like a rather impossible question given the large number of permutations.
If you have a look at our wiki you will find many excellent articles on these subjects (a good number written by competent and respected uk.d-i-y regulars like John):
OK, OK, looks like I am outvoted on this one :)
I stand corrected and will try harder in future.
Ger.
I was actually :-)
ger had already told us in his first post that he had a Baxi. As Geoff points out that's like saying you have a Ford or a Vauxhall. Then he said it a second time as though that helped ...
Like a smile, as long as you keep an 'i' on it.
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