Immersion heater

Burgerphone

Hi everyone,

I've just moved in to a new flat and could use some help figuring out the cheapest way for me to use my water immersion heater. I've only ever had a gas combi boiler so this system is completely new to me; forgive me if I seem a little dense. The heating is provided through electric wall heaters (not storage heaters).

The water cylinder itself has 2 heating elements that are linked to the control panel with the timer and on/off switch on it. I can only assume that these are for the peak and off-peak electricity so that economy 7 can be used.

I had a look at the electricity meter and it has a sticker on it saying 'converted to single rate'. Does this mean the meter cannot be used for economy 7 since it isn't multirate? And even if I did have a multirate meter, would it be worth me having economy 7 since it is only my hot water and not my heating which use the tank? I haven't spoken to the electricity company yet as my letting agent are contacting them with my meter readings, and I'm assuming they will send me a letter after they have those.

I also wanted to know how would be best to use the immersion heater for showering and washing up. The control panel has a light for 'off peak' and one for 'boost' as there is a boost button which can heat water for 15, 30, 60 or 120 minutes. The instruction manual (which is relatively useless) says that the panel's factory settings mean that the unit will heat water between 3:30am and 7:30am. However, I got up at 7am and the hot water wasn't on, even though the clock on the timer is correct. I tried the shower and it was only lukewarm, not hot enough for a shower. So I don't know what that's all about.

What I would like to do (if it turns out I will be on a standard meter tariff rather than economy 7) is heat enough water on the timer so I can have a shower when I get up on a morning. Then if I need some more hot water for washing up I could use the boost button, as it seems pretty good at heating the water quickly. Would this be a cheap way of getting the hot water I need? Is there a better way of doing it if I'm on a standard meter? I know the idea with economy 7 is to heat it cheaply overnight then you've got enough hot water for the rest of the day, but would there be any point in heating the whole tank through the night when I live alone and the electricity won't be any cheaper? Is it a good idea to use the boost button to heat water as I need it, or would it be expensive?

Sorry for the extremely long post and if there are any typos; I'm writing from my phone!

Cheers in advance for any advice.

EDIT: I was mistaken about the heating; I found the epc which states that the heating is through electric storage heaters. For hot water it says 'electric immersion, off peak'.

HappyMJ

If you do not have storage heating the switching to an E7 will not be economic. It'll cost you more. What did the EPC say about the property before you moved in? I would not think about moving into a property that does not have a cheap source of heating. E7 or gas only.

You are in now so just time the water to come on for 1 hour the hour before you need the hottest of the water such as when you have a bath or need to wash the dishes. The boost button will be fine but it won't heat enough for a full bath of hot water as it just heats the top part of the cylinder. The main immersion element at the bottom of the tank will heat the whole cylinder.

macman

A properly lagged tank will keep the water hot with minimal loss, so more economic to heat it during the cheap rate hours. And any heat loss warms the property during winter anyway.
Using it on boost during peak rate hours will cost about 300% more per kWh.

Burgerphone

HappyMJ wrote: »

If you do not have storage heating the switching to an E7 will not be economic. It'll cost you more. What did the EPC say about the property before you moved in? I would not think about moving into a property that does not have a cheap source of heating. E7 or gas only.

You are in now so just time the water to come on for 1 hour the hour before you need the hottest of the water such as when you have a bath or need to wash the dishes. The boost button will be fine but it won't heat enough for a full bath of hot water as it just heats the top part of the cylinder. The main immersion element at the bottom of the tank will heat the whole cylinder.

Hi, thanks for your reply. Which part of the epc are you referring to? I think I might have misplaced it somewhere so I haven't got it to hand. All I can remember is that it's epc rating was a B.

[Deleted User]

Hi,

maybe your shower heats the water as you use it, so won't need a full tank, and for washing up just boil a kettle once a day.

HappyMJ

Burgerphone wrote: »

Hi, thanks for your reply. Which part of the epc are you referring to? I think I might have misplaced it somewhere so I haven't got it to hand. All I can remember is that it's epc rating was a B.

The bit that refers to heating. There is no way possible a property with electric on demand heating will be a band B. My property is modern, well insulated and heated by gas and it's in band D. Most properties heated by electricity will be F for storage heating or even G for electric heat on demand radiators/convector heaters.

You can look a your EPC again online if you don't have it.

Burgerphone

HappyMJ wrote: »

The bit that refers to heating. There is no way possible a property with electric on demand heating will be a band B. My property is modern, well insulated and heated by gas and it's in band D. Most properties heated by electricity will be F for storage heating or even G for electric heat on demand radiators/convector heaters.

You can look a your EPC again online if you don't have it.

I've found it online now. I must have been mistaken about the heating, as the epc says electric storage heaters. I don't know how these work either! But yes the epc rating is a B.

HappyMJ

Burgerphone wrote: »

I've found it online now. I must have been mistaken about the heating, as the epc says electric storage heaters. I don't know how these work either! But yes the epc rating is a B.

To be a band B I'm sure you need a heat pump, solar PV, solar heated water, wind turbines or some other expensive system installed to save enegy. Are you sure it's the current figure you are reading and not the potential figure?

Anyway, the storage heaters will have two dials. Input and output. If it's warm you turn input down and if tomorrow is going to be cold you turn input up the night before. Always turn output right down.

When you want heat later in the evening you turn the output up and when you go to bed you turn the output dial down again which keeps the heat in the bricks for longer until you need heat the next evening. Try not to ever use the boost button/switch as that will cost a lot more than E7.

It's a lot of trial and error and it costs just a little more than gas when used correctly but it costs much less to maintain so for small flat it can be cheaper.

Burgerphone

HappyMJ wrote: »

To be a band B I'm sure you need a heat pump, solar PV, solar heated water, wind turbines or some other expensive system installed to save enegy. Are you sure it's the current figure you are reading and not the potential figure?

Anyway, the storage heaters will have two dials. Input and output. If it's warm you turn input down and if tomorrow is going to be cold you turn input up the night before. Always turn output right down.

When you want heat later in the evening you turn the output up and when you go to bed you turn the output dial down again which keeps the heat in the bricks for longer until you need heat the next evening. Try not to ever use the boost button/switch as that will cost a lot more than E7.

It's a lot of trial and error and it costs just a little more than gas when used correctly but it costs much less to maintain so for small flat it can be cheaper.

Hmm I wonder if the storage heaters were replaced, as there doesn't seem to be two dials on the heaters. The epc is from 2009 so I suppose it is possible. I also looked at an epc certificate for another flat in my building which I know has the same heaters as mine, and it says 'room heaters, electric' rather than storage heaters. It's all very confusing, and the letting agent wasn't much use in figuring out how to use it. I'm definitely looking at the right figure on the epc; the current rating is 83 with a potential of 84. The other flats in the building seem to have similar ratings.

[Deleted User]

Hi,

well you say in first post that meter has been converted to single rate, which means no E7 or cheap rate.

Sounds as though you have panel heaters, which will be expensive to use.

[Deleted User]

Hi,

storage heaters look like this,



panel heaters look like this,