Is it unreasonable to turn the immersion heater off, help and advice needed!

[Individewl]

We have an extremely old immersion heater, just a tank with a switch, no timer attached. We have been leaving it on 24hrs basically through ignorance and not knowing how it works. Now energy prices are going up I’m looking at ways to save.

we live in a social housing, the property is fully electric with old storage heaters and immersion heater, we are not on an economy 7 tariff just a variable. We are unfortunately on a pre-payment meter left by previous tenant and energy company refused to remove it and said a smart meter cannot be used for our property. Our electric use for last year was 5925khw! But we did have to use fan heaters through winter because storage heaters broke and housing association took 3 months to fix it.

advice please on how to use an immersion heater so we use less energy, I was thinking of turning it off and putting on for a few hours per day?

if you made it this far well done, didn’t want to drip feed!

Also forgot to add, medium sized 2 bed flat 2 adults 2 children

You could pay to get a timer plug installed. You'll probably recoup that pretty fast in saved energy costs. Immersions are greedy fuckers.

If you have storage heaters rather than electric heaters then you would be better on an economy 7 tariff as the storage heaters charge overnight.

Try putting the immersion on for an hour or two before you need the water. If the water cylinder is insulated then it should retain heat. My hot water is only on for 1 hour a day as we have electric showers and the appliances are cold fill.

I would write to your housing officer and call Shelter and your energy provider and explain it is inefficient . If you just turn it off the water will go cold and need to be heated up. Buy some oil filled plug in radiators which are much better than fan heaters.

How is it wired up? We had one with a 3 pin plug so could use a plug in timer switch.

It takes about half an hour for my immersion to get piping hot. Not a massive tank 150 L. Just pop it on half an hour before you’d normally wash , tweak times once you figure out how long it takes, 5-10 minutes longer in winter when water needs more heating. I put mines on for 15 minutes in morning and I have a warm shower half an hour at night for dc to wash generally.

I don’t think the energy company are allowed to refuse to remove the pre payment meter. Write to your Mp. They should help you get it removed. The costs for that are usually more expensive I think.
We moved into a property that had a pre payment meter and we had it removed and replaced with a regular one. You are the customer. Not the energy company.

I have the same set up, storage heaters and immersion. A plumber once told me it uses more money to heat up from cold than it does to leave it on all the time. I haven't turned mine off to test this though. I don't have a shower so need the water for a bath every day.

Admittedly we have two tanks but I generally put mine on for an hour or two every other day and that gives plenty of hot water. If your tank doesn’t have a jacket, I recommend one for keeping the water hotter for longer.

My parents only have an immersion heater. They turn it in for 30 mins to an hour in the morning and again later in the day if having a bath in the evening. Washing dishes etc they boil a kettle.

We used to have an immersion heater when I was growing up. We would always switch it on half an hour or so before someone wanted a bath and Mum used to tell us off if we forgot to turn it off again! We never left it on all the time as it used a lot of electricity

we Had a huge problem with the storage heaters last winter as they weren’t wired right and weren’t coming on because we didn’t have economy 7, I went to housing and energy company and after lots of back and forth was told the prepayment meter is too old to be changed to economy 7 tarrif because of the way it’s wired and they can’t touch it because it’s down to the national powergrid. I was told and electrician is allowed to do so much, after that point it’s an engineer from the energy company and after that point it’s national power grid. I rang powergrid and they told me nothing they could do and to go back to my supplier! So frustrating 😔

Sounds like your plumber knew how to break the laws of physics.
Although if the tank is somewhere that the heat it loses will usefully help heat the house it's not so bad I suppose.

I don't think I've ever come across anyone with an immersion heater who left it on all the time though.

This totally depends how insulated the water cylinder is. It is supposed to be a myth that it is cheaper to leave it on all the time and that it's best to have it on for shorter periods. If the cylinder is insulated the water should stay hot anyway and won't be heating from cold all the time

The best plan is to test it. Run it for 24hrs or a week if your usage varies checking your meter before and at the end of the week, then doing it again the following week switching it on/off. Assuming outside temps don't massively vary in that time it will be easy to see.

We have a family of 6 and we NEVER have the immersion on at all

Immersion heaters usually work quite fast and absolutely gobble power - turn it off, just turn it on half an hour or so before you want hot water, or better yet get a timer put on it. We only heat our hot water tank for an hour in the morning during showers etc and half an hour in the evening so there’s hot water for face washes and washing up. If we had electric showers I’d only have it on in the evening. You don’t need hot water on tap 24/7, especially when you’re asleep or out at work.

Do you have an electric shower?

I put my immersion on every three day (overnight) and it stayed hot enough for hand washing and dish washing. By the end of day three I might have topped up sink with a kettle. I showered in the electric shower.

Putting it on for an hour won't make much difference as it won't heat the whole tank in that time.

Mine had a boost button that would hear you a 1/3 of an extra tank if you needed it.

Very expensive sadly. Get E7 tariff.

How do you get hot water then?

My DC inherited a property and the old, inadequately insulated tank was costing the tenants far too much. We put in an electric shower and an under sink in-line water heater for hand washing and kitchen.

Along with efficient heaters the property went from EPC E to C.
Basically only heat what you need unless the insulation is excellent.

Well that's fine if you have a gas boiler that is heating the water instead. If you're electric then if you don't use the immersion you will never ever have hot water

I was looking at timers, unfortunately it’s not 3 pin plug but an isolated switch. I’m not allowed to change it due to my tenancy, I could ask the HA for permission though.

Sorry, that was completely lacking in advice and all about my dc situation.
Only turn off the immersion if you have excellent insulation or if every time you use it you empty it completely, so you aren't just wasting hot water.
If you can get your LL to fit an electric shower it will save you heating a whole tank.

Do you have a dishwasher and electric shower? We only ever put our (extremely old) immersion on for a few hours if we fancy having baths that evening. Otherwise it's always off. We haven't had hot water on tap in years but it only really works if you've got a dishwasher and electric shower.

Usually wired up to 3k heater. So if your unit price atm is let’s say 10p per kWh it’s 30p an hour to run (only an example). lag it to an inch of its life, & put a clock on it? It is after all one gigantic kettle. It’s either off or on, alternative thing to do if you want an immersion heater I’d remove & replace with factory cladded one