Immersion heater boost costs?

Marshyman

Hi everyone,

Heres the situation...

I have a boiler in my flat that i own which has 2 immersion heaters on it 1 labelled off peak and 1 labelled boost. Recently the off peak has stopped working and so the water is now being heated using the boost immersion which is left on 24/7

Ive had a plumber attempt to change the off peak immersion but the thread is so corroded that it will not come off! If we tried any harder we risk damaging the whole boiler

My question is what is the likely increase in costs im going to face by having to use this boost immersion constantly

I am on the e.on energy standard energy plan

I am trying to weigh up the two against each other whether its better off carrying on as i am now or forking out for a new boiler all together

Look forward to your replies, Thanks

HappyMJ

You won't get as much hot water using the boost element only so get it fixed. It'll be costing around 3 times more than the e7 element that just runs at night heating the whole cylinder....

molerat

During off peak hours your electricity will cost you in the region of 7p per unit.
During the day in the region of 18p per unit.

I assume the boost heater is near the top of the tank so will not be heating the whole tank. Leaving it on 24/7 is costing you money. Try to use it during the off peak hours if you can to reduce the cost. Get it fixed.

Marshyman

Thanks both,

The boost element is actually at the bottom of the tank and the off peak is about half way up if this makes a difference?

Off peak times im assuming are 12am - 8am approx?

I will ultimately get it fixed however i dont have the funds to pay for it just yet (dont you love how problems like this pop up around Christmas!) so for now just getting some ideas of the smartest way to use it

lstar337

Marshyman wrote: »

Thanks both,

The boost element is actually at the bottom of the tank and the off peak is about half way up if this makes a difference?

It means it is wired incorrectly.

The E7 needs to be at the bottom and the boost nearer the top.

Somebody put your tank in wrong, or fiddled with it after installation.

Marshyman

Oh right think its always been that way too! Does this mean then that the immersion heater that is working is actually the off peak one?

lstar337

The one at the bottom should be off-peak, that heats the whole tank overnight using cheap electric.

The middle or top element is for a boost, and should only be used in an emergency (you run out and need more hot water). The boost element is designed to heat a smaller portion of the tank quickly. The boost costs 3x as much as the E7.

If the bottom element works, get the E7 connected to it as this should provide you with ample cheap hot water. Ideally, the boost should never be used.

Marshyman

Ok thanks again,

So if I changed over the wire that is currently going into the boost switch over to the off peak switch would this solve the problem? Sorry if this seems a silly question but it's the easiest way to get it right in my head

lstar337

Without know the exact details it would be irresponsible for me to say. But if the two elements are the same type and size, then yes. It might be best to get an electrician to take a look at it for you.

footyguy

Marshyman wrote: »

Hi everyone,

Heres the situation...

I have a boiler in my flat that i own which has 2 immersion heaters on it 1 labelled off peak and 1 labelled boost. Recently the off peak has stopped working and so the water is now being heated using the boost immersion which is left on 24/7

Ive had a plumber attempt to change the off peak immersion but the thread is so corroded that it will not come off! If we tried any harder we risk damaging the whole boiler

My question is what is the likely increase in costs im going to face by having to use this boost immersion constantly

I am on the e.on energy standard energy plan

I am trying to weigh up the two against each other whether its better off carrying on as i am now or forking out for a new boiler all together

Look forward to your replies, Thanks

Marshyman wrote: »

Thanks both,

The boost element is actually at the bottom of the tank and the off peak is about half way up if this makes a difference?

Off peak times im assuming are 12am - 8am approx?

I will ultimately get it fixed however i dont have the funds to pay for it just yet (dont you love how problems like this pop up around Christmas!) so for now just getting some ideas of the smartest way to use it

Marshyman wrote: »

Oh right think its always been that way too! Does this mean then that the immersion heater that is working is actually the off peak one?

Marshyman wrote: »

Ok thanks again,

So if I changed over the wire that is currently going into the boost switch over to the off peak switch would this solve the problem? Sorry if this seems a silly question but it's the easiest way to get it right in my head

Assuming you are on E7, then it doesn't matter which heater is being used, but the time the heater that is on.
If it's on in the low (off peak) rate period then you pay low rate electricity. If it's on during the normal rate period, you pay normal rate electricity.

As said, usually the heater marked off peak is the one lower down as it heats the whole tank. The heater marked boost would then only heat about the top 30%.

The heater marked as off peak circuit may only operate during the low rate period ... but not necessarily. (e.g. it may operate via a timer instead)

From what you've said, you've been living quite comfortably using the heater that only heats the top 30% of the tank?

In which case, switching the wires around (which I would urge you to consult a qualified electrician to do) would not solve your problem. It'll end up costing you a lot more as you will now hea heating 3x or more hot water every day; hot water you obviously don't need.

I suggest you get a plumber and electrician around (could be one person with qualifications in both) to fix the problem properly.

That means fixing the immersion heater. If that needs a new tank too, then so be it.

It also means getting the wiring sorted out.

Whilst you are at it, I suggest you get a timer fitted for the upper heater (which should operate as the boost) and then you can just use that during the low rate (as you have always done in the past). Then you won't need to use the correctly wired (lower) off peak heater at all,

Whilst the plumber/electrican are sorting all this out for you, you can spend time looking for a better electricity deal. e.on energy standard energy plan is not cheap.