Permanent live to a boiler

[ian hall]

I do a lot of work for a heating company-combi,s, s and y plans etc. Modern boilers and some back boilers(tomorrows problem) need a permanent live for diagnostics or gas fire ignition. If it was impossible or really difficult to run another cable back to the airing cupboard, would you consider just wiring a local spur. I have been asked to do this and am not sure if i am happy doing it!!!!


Ian

 

[andyb]

As you describe it I would say defiantly not.
The problem you have is that the spur by the boiler would be taken by a future engineer to be the boiler supply, and after switching off the boiler could still be live. Also the same could apply to the boiler controls in other parts of the house where, when isolated locally could pick 230 volts from the boiler spur.

 

[Spudnik]

Agree with Andy, but surely as long as the wiring centre and boiler are labelled stating that maybe wiring centre and boiler should be isolated before maintenance, then that should not be a prob?

 

[andyb]

I agree Jason, but the problem with that is that we have no information on the electrical installation and it could lead to the parralleling of 2 circuits through the boiler with all the problems that that brings.

 

[Spudnik]

Yes sorry i see your point.

 

[old dog]

hi ian can you give me more details on the set up .
position of programmer valves ect
if the spur and the supply for the programmer can be put on the same circuit
got an idea moving programmer to boiler and working backwards
this is not making much sense at the moment give me some more
info and i will explain

 

[ian hall]

Assume that the main supply is upstairs in the airing cupboard together with the clock,vave(s) etc. There is just a t/e running down to the boiler. Clever heating firm come along and fit an Icos boiler that needs a perm live or a back boiler that has lights in the front or electronic ign for the gas fire.
Normally i insist that a new 3 core/earth is installed, but tomorrow,s job apparently that ain,t gonna happen!
They reckon i should fit a 3 pole switch with the switced live and neutral then spur off a local socket for the perm live taking that through the 3rd terminal of the 3 pole. Phew! The 3 pole would then give means of isolation at the boiler but there would still be 2 different supplies at the boiler.

Ian

 

[old dog]

Assume that the main supply is upstairs in the airing cupboard together with the clock,vave(s) etc. There is just a t/e running down to the boiler. Clever heating firm come along and fit an Icos boiler that needs a perm live or a back boiler that has lights in the front or electronic ign for the gas fire.
Normally i insist that a new 3 core/earth is installed, but tomorrow,s job apparently that ain,t gonna happen!
They reckon i should fit a 3 pole switch with the switced live and neutral then spur off a local socket for the perm live taking that through the 3rd terminal of the 3 pole. Phew! The 3 pole would then give means of isolation at the boiler but there would still be 2 different supplies at the boiler.


Ian

i understand there thinking with the triple pole as means of isolating all lines to the boiler
however i would not be happy with the 2 supplies in the triple pole switch my first approach
would be to try and find a route for cable from programmer to boiler well you will find out when you see the job goodluck mate

 

[andyb]

If there is no easy route from the control box to the boiler, how about feeding the boiler from a local spur as suggested then feed the boiler demand from the same supply but take it through a relay mounted next to it. The pair coming from the boiler control box would then energise the coil.
Still 2 supplies at the relay which could be labelled, but they would be separate from each other.

 

[maddfridge]

I do a lot of work for a heating company-combi,s, s and y plans etc. Modern boilers and some back boilers(tomorrows problem) need a permanent live for diagnostics or gas fire ignition. If it was impossible or really difficult to run another cable back to the airing cupboard, would you consider just wiring a local spur. I have been asked to do this and am not sure if i am happy doing it!!!!


Ian

hi there
i was playing with one of these boiler set ups this week.

thinking about a small inverter and battery pack just for localized testing 3 port valve etc.
usefull for fire alarm panel testing sometimes

cheers

 

[mrloy99]

Assume that the main supply is upstairs in the airing cupboard together with the clock,vave(s) etc. There is just a t/e running down to the boiler. Clever heating firm come along and fit an Icos boiler that needs a perm live or a back boiler that has lights in the front or electronic ign for the gas fire.
Normally i insist that a new 3 core/earth is installed, but tomorrow,s job apparently that ain,t gonna happen!
They reckon i should fit a 3 pole switch with the switced live and neutral then spur off a local socket for the perm live taking that through the 3rd terminal of the 3 pole. Phew! The 3 pole would then give means of isolation at the boiler but there would still be 2 different supplies at the boiler.

Ian

Hi Ian,
I recon your easiest way out would be to ensure that you have volt free contacts at the timeclock/programmer,then take out the link,then arrange it so that your t&e going to boiler would
be your switchwires(COMING from and going back to boiler)instead of your neutral which would now be coming from your new local boiler supply.You could then fit a caution label at programmer (fed from 2 sources)But maybe too late and you've the job done

 

[andyb]

That would work mrloy99 if the valves and pump were by the boiler, if not you have the same problem.
A feed from the boiler after going through the time clock would need to open a valve and start the pump, both of these need a neutral.

 

[mrloy99]

That would work mrloy99 if the valves and pump were by the boiler, if not you have the same problem.
A feed from the boiler after going through the time clock would need to open a valve and start the pump, both of these need a neutral.

I suppose you would need to see the full set up,but maybe at the board the two circuits could be put
into one breaker to keep it all on one circuit,then at least the whole lot could be isolated there in one go.

 

[Guest123]

Hey Ian.

If you've already done the job then ignore this.

I came across this exact situation only about 3 weeks ago.

I had a phone call from one of the kitchen staff in the school where I had been working to say the all the little red neons on her switched fused spurs in her kitchen wouldn't go off.

When I got there the first thing I noticed in the corner of the kitchen was a shiny new worcester boiler which a large Anglo Fossil Fuel company had that very day installed.

Sure enough no matter what way the switches on the spurs were, the neons stayed on, never done that before she said

Anyway I'm going off on one here so to cut a long story short BG had spurred off the kitchen ring to feed this new boiler as there was only the T+E coming down from the wiring center in the airing cupboard. Now all was fine as long as the boiler spur was turned on but when she turned this off thus removing perm live supply to boiler all the neons in the spurs lit up.

Reason - switched live still present from timer upstairs running through boiler and out via prem live supply backfeeding (only a small amount of voltage) onto kitchen ring.

Moral of the story install new 3c+cpc.