2 x Immersion switches - 1 restricted 1 unrestricted - Diff?

[MirfDiver]

The house we just bought has an annexe with a seperate power supply.

Heat is provided via storage heaters and hot water by a big immersion heater.

The immersion heater has 2 x switches for it.

One that is labelled as 'restricted supply' and the other as 'unrestricted'.

Ideally I'd like to get a timer fitted to the hot water switch but am just not entirely sure why there would be 2 switches and what the difference might be.

Any ideas?

 

[kevindgas]

top element - unrestricted can be on at anytime to provide hot water
bottom element - restricted (economy 7 or economy 10) will only come on at night during low cost period for electrics

no point in putting a timer on the lower one as you want as much heat at low cost as possible
timer on upper one should be set to come on at 8am go off at around 6pm this way you get as much hot water as you can if you are a high user set the off time earlier if you don't use much hot water

 

[MirfDiver]

Aha, ok now that makes perfect sense. Why didn't they just label it economy 7! Oh well. I've found my 2 x fuse boxes now and one clearly says restricted. Suddenly its all starting to make sense. Cheers

 

[OwainDIYer]

Check the 'restricted' immersion (the bottom one) is actually connected to the off-peak board.

You can get Economy 7 water heater timers that handle the off-peak period as well as a timed boost for the top heater. Internal links make them work on single or dual circuits.

 

[MirfDiver]

Good to know. I'll look at getting a timer I think as it'll be more cost effective having a renter in there.

Any idea what the plug and plug socket might be? I can only assume/presume its the plug for the immerision heater which is behind the wall. More investigation required!.

 

[OwainDIYer]

What plug and socket?

 

[Whitespirit66]

Any idea what the plug and plug socket might be? I can only assume/presume its the plug for the immerision heater which is behind the wall. More investigation required!.

Immersion elements should have their own fused spurs. Elements shouldn't ever have standard 13amp plugs. I'm hoping that if you are referring to plugs, they are for something else.

Re. timers. The Horstmann economy 7 timers as shown in Dwain's post are the best way to control E7 and standard tariff suplies to your two elements.