Immersion Heater help!

Justadmin88

Hiya,

We're in the process of moving in to a new home (we have a week's overlap with the old one) and I'm trying to get my head round the hot water system. I need help!

It's an immersion heater, the tank is in a cupboard in the bathroom. Next to the heater are two switches (the kind that look like light switches) and they're one on top of the other. The one at the top links to a timer unit and goes into the top bit of the immersion tank, the one at the bottom just goes straight into the tank. The bottom one is currently off (we're not properly living there until Saturday so I thought I'd keep it off for now) and the timer on the top one is set to come on between 6 and 8 in the morning and then 5 and 9 in the evening (that's if I've interpreted the timer properly anyway!)

Can anyone advise how I should go on to use this system once we're properly moved in? The house doesn't appear to be linked up to Economy 7, although our meter does give a day and night reading. Really I want enough hot water for two baths and a bit of washing up each night, and a bit of hot water too for "sink use" throughout the day (mostly at weekends).

In out outgoing house we had economy 7 and the water heated overnight and we were free to use it whenever the next day. Could I set the timer to do the same in the new house or would that be really expensive?

Sorry, I'm really confused! The world of heaters is all quite new to me!

Many thanks for any advice and thoughts

[Deleted User]

Hi,

what do you mean you don't seem to be linked to E7, when you have a two rate meter?

What kind of heating have you?

Justadmin88

Hiya,

The heating for the house is only really one electric fire in the living room (it's a one bed terrace) and all the water comes from the immersion. I did think it was weird about having two readings but not having E7, but the chap at British Gas seemed certain we didn't have it? From a bit more reading online I understand that the bottom switch should be for the E7 and can be left on all the time, and the top switch is for "top ups" - to which the previous owners attached the timer. So confused by it all!

[Deleted User]

Hi,

mmm, seems odd.

Well the switch on the timer can be set to times to suit yourself and the other must be the 'boost'.

Strange that you have a two rate meter, unless previously there was electric storage heaters, which have been removed, and the two meter readings are combined for a single rate.

You will have taken a meter reading, so check it regularly.

facade

The heater at the bottom will heat all the water in the tank (hot water rises to the top, cooler water falls to the bottom)-you really want to do this on E7
The heater at the top will heat just the top, to give a little hot water for washing up, when the tank is completely cold.

Best plan (to me) is to really really lag the tank to keep the heat in and run the lower heater through a timer overnight on E7 if you want baths every night,(this hot water has to stay hot all day though, hence the thick insulation) and the top one stays on permanently, then there will always be some hot water. The immersion heaters switch off at a set temperature, so the top one should never come on unless you use up all the hot water in the tank.

Justadmin88

Thanks everyone, it certainly is a puzzle. I am going to call British Gas again and just ask again to check that E7 definitely isn't installed and then get a timer for it if necessary. In the mean time I guess "turn on only when needed" is the best option?

Smiley_Dan

It's not odd to have two readings but no E7... plenty of off-gas grid houses have this where the default meter installed is capable of recording two rates, but there's not necessarily an E7 contract in operation.

When you move into the new property you will be on a deemed contract with the supplier that the previous occupant used. What I'm not sure about is if the previous occupant was not on E7, maybe the deemed contract also is not E7 by default?

With regards the immersion heaters, depending on the length of the coils, the top one can be used for a smaller amounts of hot water, the bottom one to heat the whole tank.

For your requirements it sounds like you will need the bottom immersion to run.

"Turn it on when needed" is *always* the correct option.

The upside of the bottom immersion is that if you install solar PV (worth considering especially when you are off gas grid) you can get a whole tank of hot water for free.

Justadmin88

Thanks Smiley Dan.

Would you mind explaining what an off-gas grid house is? We are just electric in the new place, would that mean we're off-gas?

I've already set up an account with the current provider at the property (British Gas) but they are charging a huge monthly DD - £86 compared to £41 with Southern Electric in our previous place, which is exactly the same kind of house as our new place (in fact it's in the same terrace!) I will call British Gas again ASAP and really get some clarification on what the E7 situation is.

Good idea about solar power, I was thinking just earlier today that I might look at that within the next year or so!

[Deleted User]

Hi,

could you put up photies of immersion heaters/switches, and meter set up please, might help.

Smiley_Dan

Justadmin88 wrote: »

Thanks Smiley Dan.

Would you mind explaining what an off-gas grid house is? We are just electric in the new place, would that mean we're off-gas?

It just means a house where there's no mains gas available nor within easy connection (occasionally houses are in a street with gas, but not connected for some reason - such houses are still counted as being on the gas grid).

I've already set up an account with the current provider at the property (British Gas) but they are charging a huge monthly DD - £86 compared to £41 with Southern Electric in our previous place, which is exactly the same kind of house as our new place (in fact it's in the same terrace!) I will call British Gas again ASAP and really get some clarification on what the E7 situation is.

Sometimes their initial estimates are way off. I don't know how they decide it. Happened to us too and we ended up with several hundred pounds of credit.

Good idea about solar power, I was thinking just earlier today that I might look at that within the next year or so!

It especially makes sense for off gas grid properties when a solar diverter to the hot tank is added.

macman

If you do not have E7 and are heating purely by electricity, then your DD may well be correct at around £86. Because without E7 you pay around 300% more per unit, compared to the cheap E7 night rate, so your costs will be massively higher on single rate.
The only way to heat this property cheaply is to get NSH's installed to compliment the dual element immersion heater.