Options for limiting max power in a house

Hi,

I am contemplating a switch from oil-fired central heating to electrical (notwithstanding the horrendous increase in running costs that will entail). However, when I consider the peak energy demands from all the significant appliances in my house, collectively they exceed the 100amp fuse rating on my mains. I understand it is possible to fit a relay to ensure that, for example, when an electric shower is used, power to an electric boiler is temporarily switched off. Are there switching systems that provide more flexibility than simply switching between two devices? For example, could it be arranged that power to an electric boiler is turned off if the aggregate consumption through the consumer unit exceeds a certain threshold?

All advice gratefully received!

Many thanks,

Denis

You can but then you are getting into realms of BEMS equipment which costs significantly as you will need a software written to suit your needs. 
without software then I can’t see an easy fix. 

WHY are you considering an electric boiler?  Why not stick with oil?  f you must switch to electric, consider an Air Source heat Pump.

You are obviously already aware of the extortionate price of electric power. The running cost will depend very much on the design of your house and particularly the insulation and, (in my opinion) whether you like to open windows for fresh air.

I had electric heating about forty years ago, when it wasn't so pricey and even then it couldn't compare with the alternatives on either performance or cost. The heater units may have improved but not that much. Most of the, "improvements",  I've seen to amount  to limiting the heat output with complex controls.

If I couldn't get mains gas my alternatives would be LPG or oil, in that order.

Fiest off, what is likelyhood of everything being turned on at the same time? Secondly, have you done all the things like loft insulation / cavity wall insulation? 

If the only likely conflict (overload) turns out to be an electric shower and the boiler then I think a simple and economic solution may be possible.

I would expect that an electric boiler will be controlled by a contactor.

If another contactor is installed to control the shower circuit, then an auxiliary switch, wired to the boiler control contactor coil, could be used to prevent the boiler coming on.  

I would be gobsmacked if a UK home pulled 100A for any period ……

Hi Everybody,

Many thanks indeed for all your suggestions.

Can you answer this question from ProDave:

"WHY are you considering an electric boiler?  Why not stick with oil?  If you must switch to electric, consider an air Source heat pump."