Help with airing cupboard wiring

[dan1w]

I need to install a shower pump in our airing cupboard (not in the bathroom) and was wondering if I could put an FCU on the circuit before the wiring for the diverter valve, central heating pump and hot water tank thermostat. However I can't figure out what's going on with the wiring.

The wiring for div valve, CH pump and HW tank are connected to a chocolate block behind a plate on the wall which obviously goes off to the CH timer. Above that there is a switch which you would assume isolates the supply to the above. In that switch there is one twin & earth cable but the wiring seems to go back down to the CH timer with the other wiring and doesn't actually seem to isolate anything in the airing cupboard.

What is the purpose of that switch and is it possible to run my shower pump off of it?

My house was built mid-80's if that is of any relevance.

Any help much appreciated.

 

[bernardgreen]

What is the purpose of that switch and is it possible to run my shower pump off of it?

It isolates the supply to the timer / programmer and all the central heating controls and equipment for servicing and when necessary to shut down the system.

No you cannot use any of that wiring to supply the shower pump.

 

[dan1w]

Thanks for your reply Bernard. However it doesn't isolate the timer either, there is a seperate isolator in the kitchen where the timer is located.

Any other ideas?

 

[electronicsuk]

If there's just one T+E at the switch then I'm doubtful it's an isolator, although exactly what it does is anyone's guess. Can you not trace the wiring back properly to identify the switches function?

 

[ricicle]

Surely it's an immersion heater point

 

[dan1w]

I don't have an immersion heater.

 

[dan1w]

The wiring seems to follow the CH control wiring downstairs into the Kitchen where the timer is. I'll have to take the FCU off down there later to see if it reappears.

 

[ricicle]

I don't have an immersion heater.

Possibly wired in though as a provision. Is there any clues at the CU ?

 

[bernardgreen]

The heating system supply for a few houses near here had two switches in series for the supply to the heating system. One by the timer ( kitchen) and one by the hot water tank, pump and divertor valve ( airing cupboard on landing ). Both had to be on for the system to work.

Possibly the switch by the OP's pump isolates only the pump valve etc leaving the timer powered.

Or as some one has suggestted there is provision for an immersion heater. If that is the case the switch would be a double pole one.

 

[Beelzebub666]

Have you checked if there's any juice to the switch? It might have taken involuntary redundancy at some point in the past. Regardless you can't use it if you don't know what it is.

 

[dan1w]

Thanks again for the replies.

Ricicle you are right, it's an old switch for an immersion heater. There's a 15amp fuse for it in the CU I didn't know the purpose of and I hadn't noticed the faint remains of a long ago written legend on the inside of the fuse cover!

So seeing as the immersion is no more, can I put a 5amp FCU or socket in place of this switch and use it for the shower pump?

 

[dan1w]

Or perhaps just a 5 amp fuse in the CU?

 

[Beelzebub666]

Full instrutions on the wiring requirements will come with the pump.

 

[dan1w]

Got the wiring instructions but haven't had a house with an immersion for years. When I did there was an immersion timer associated with it that was obviously attached to the same circuit as the immersion. I also have no experience of putting anything on a radial circuit and don't know if there are any other considerations.

Whilst I know full well how to wire in the pump. The pump handbook isn't going to tell me what I can do with an unused immersion heater switch.

I suppose the easiest thing to do is dig out the tool box and see if it's live.

 

[Beelzebub666]

Got the wiring instructions but haven't had a house with an immersion for years. When I did there was an immersion timer associated with it that was obviously attached to the same circuit as the immersion. I also have no experience of putting anything on a radial circuit and don't know if there are any other considerations.

Whilst I know full well how to wire in the pump. The pump handbook isn't going to tell me what I can do with an unused immersion heater switch.

I suppose the easiest thing to do is dig out the tool box and see if it's live.

The pump handbook will specify the cable rating, the fuse rating, any isolation switch requirement and whether RCD protection is required (it is). Basically all you need to know.