All Electric limits

I recently moved to a house that is all electric. There is no main gas supply and I do not have lpg or oil.

Now winter is approaching I am thinking about turning the heating on (NSH) and thoughts turn to other electrical appliances - instant inline water heaters, extra radiators etc.

I have a worry about the total power consumption that we could incur at any given moment (as I imagine must be the case for many people with all electric homes). The main fuse is 'only' 100A. Surely there must be some combination of appliances that would exceed that rating? Is 100A the most that can be supplied to domestic premises?

Some inline water heaters that would provide a lot of hot water and bath and shower are three-phase - is that allowed in domestic premises?

I came from London and had electricity and gas so the house had a split between the two. Now on reflection, all-electric seems to offer some limitations (apart from cost of running).

Any views?

Dont worry about it. There are thousands of houses with NSH and eco7 etc, on 100 amp fuses. Many are even on 60 or 80 amp fuses with no problems. A 100 amp fuse will let through quite a significant gradual overload before it blows. Its main reason for being there is short circuit protection. The DNO (supplier) cables are normally undersized anyway.


As an aside if you're interested in ways to save money on bills, ground source heat pumps (and plain heat pumps to a lesser extent) are a genuinely cheaper to run alternative to plain electric heating. They can be up to 400% efficient and the heat is there when you want it, unlike NSH, which is less than 90% efficient (i guess), and lets heat out in the morning/afternoon, when you only really want heat in the evening.

Oh, and GSHP can also cool your home in the summer.

You could start by checking:

What hours do your storage heaters come on?

Will you be asleep in bed at that time and therefore not using the cooker, electric shower and tumble drier?

How many heaters do you have and what is their power rating?

How is your water heated, and how much is stored?

Thanks Steve. I have thought long and hard about Heat pumps (both air and ground) and looked into it. The upheaval is not very attractive and the cost of a bore hole is as much as the unit. The outlay is high but as you say running cost relatively low. Not sure that it is cost effective for me - although I am very attracted by the idea. Air source I am not too sure about as it is less effective the colder it gets outside - when you need it most.

I AM toying with thermo-storage central heating using the off-peak to 'charge' the thermobank. But that remains to be seen. I would like central heating again that is more controllable (ie when I want it) but I must say I am not too keen on the mess and upheaval of the fitting of pipes etc.

At present I am about to start using the NSH in earnest, and am buying a Duoheat radiator from Dimplex as it does seem to be very good. This will replace the NSH I have removed from my kitchen whilst having a refit. I need my lecky to add a new point for it.

This is where I came in - starting to worry about total loads etc. I take your point John, in working out the total - it isn't likely that we will be doing the washing, having a shower at night when all NHS is on - maybe we should leave the TV off.