Economy 10 power supply?

avfryer

hi, just moved into my new flat and have economy 10 with electric heat and water.
when the boiler broke (was under warranty) the manufactures came around and said there was only one supply and the boiler should have two power supplies one for peak and one for off peak so to contact the installer. when the installer was contacted he said there should only be one power supply. can anyone clarify?

mute_posting

If there is only 1 supply, it should be on a timeswitch to co-incide with yout off-peak hours. (usually midnight to 5am, 1pm-4pm and 8pm to 10pm) (the time switch may be remote (i.e. by your fusebox but usually it would be by tank)

There is a email answer I got from southern electric giving some technical stuff on my E7/E10 poll...

http://forums.moneysavingexpert.com/showpost.html?p=10367101&postcount=8

Usually, these kind of hot water systems have 2 heaters and 2 supplies (as manufacturer says) - the bottom one should be on the off-peak only OR the supply via the timeswitch, the upper heater (and and controls) should be on the normal supply

The idea being that the bottom heater only comes on during off-peak and heats the whole tank, the upper heater is a boost that only heats the top 1/3 of the tank, although I'd be surprised if you nedded it with E10 (unless you use lots and lots of hot water and requarly run out) because you should be getting 3 periods of off-peak heating to the tank

Out of interest, what make/model of boiler/hot water system is it?

HTH

MP

avfryer

thanks for your reply, it is a Heatrae sadia electromax combined electric flw boiler and direct unvented waterheater. the unit has provision for the two power inputs however whoever installed it has connected the one supply to the peak terminals and then looped it over to the off peak terminals?

mute_posting

sounds like you need to fit / get fitted a time switch to control the off-peak supply.

I've not looked at the specs yet, but I would imagine that it has the potential to be very expensive at the moment because it has permenantly available electricity at the off-peak terminals (which for 14 hours per day is charged at peak rate).

Will have a look at the specs later and can maybe suggest more.

MP

mute_posting

This may help...

http://www.gasapplianceguide.co.uk/electromax%20fitting%20instructions.pdf

If you have just bought the flat from the builder / developer you may have some recourse to get them to come back and rectify the installation (In this case I would say that that would include fitting a suitable timeclock to the supply for the off-peak IH).

from what I gather briefly parsing the manual above, there should be 3 supplies to the unit, 2 x 16 amp supplies (one off-peak or timed off-peak) for the immersion heaters and a 45 amp for the seperate boiler for the CH.

It suggests timing the CH system to co-incide with the off-peak hours to economise (Page 3)

HTH

MP

avfryer

just double checked it, there is the 45amp supply connected and only one 16amp connected and looped accross to the other 16amp terminal

mute_posting

That means that the bottom IH can draw electric ANYTIME it falls below temp which is a bit like boosting the WHOLE tank (instead of just the top 1/3)

The upside is you will probably never run out of hot water.
The downside is (as you are unlikely ever to need 24/7 hot water) it will be very costly to run (as the normal rate on E7 or E10 is more than the standard rate on a 1 rate tarrif)

If you've moved in to (a new build) within the last 12 months, I'd definitely get on the phone to the builder / developer, whilst it's not "dangerous" per-se, it clearly hasn't been installed to the manufacturers specifications.

(There is a potential to overload the circuit if the upper boost is opperated simultaneously when the bottom IH is already calling for electric - it should trip the circuit breaker but the fact remains it is just wired wrong IMHO)

MP

avfryer

cheers mate you have confirmed what i suspected the installer is coming around tomorrow (it is a new build) and i will be asking for a refund on my bills (previous 3 months £330 for 3 months - 2 bed small flat) let you know what his excuse is ! )
THANKS !