What are these switches? And which one should I turn off? (Immersion Heater Help)

[Hakim92]

Hi there

Not sure if I’m on the right page but really need help.

I’m in a new build flat which is very well insulated (we don’t turn on the heating!) however, our energy bill was £125 for our first month. Even though we’ve been sensible with our use.

Octopus suggests it’s because I’ve been leaving the immersion heater on.

There are two switches with “water heater” I’ve turned them both off but one turns off the thermostat timer or something.

The other is a red switch too. Which is the switch for?

I might sound very stupid here but, my landlord did not supply information on the boiler etc so don’t want to get things wrong.

If you have any tips please feel free to share

Many thanks

 

[terryplumb]

The lower immersion element heats the whole cylinders water, the higher one heats only the water above it.
Both switches each operate an immersion ,one of them via a timer,so you can set it to heat at certain times. You can follow each cable to determine which immersion element is connected to the timer.
The red switch may isolate an electric shower if you have one?
Do you have a lower electric tariff for certain times ( usually after midnight) ,it's common to use that to heat the hot water cylinder.

 

[Hakim92]

Ohh okay thanks for that.

We don’t have an electric shower (if it’s the one with a box or whatever) it comes straight from the tap when turning on.

We actually are currently on a standard one but just finding strange why it’s more expensive than it should be for our type of flat.

Do you have any recommendations? I’ve turned them both off at the moment

Thank you!

 

[terryplumb]

Turning them both off will certainly save you money ,but you won't ever have hot water !!
As your showers hot water comes from that cylinder you will need to determine how to use the immersion heaters. The more hot water you need ,the longer the immersion needs to be on each day. Besides showering ,you probably only need hot water for hand washing and dishwashing. I would suggest you use the immersion That is connected to the timer ,and set it to come on for an hour each day ,see how you get on. If you take very long showers and there are more than two of you ,that may not be long enough.
Not sure what the red isolation switch is for. Turn it off and see what doesn't work !!

 

[JohnD]

The cost of heating your hot water is directly proportional to the amount of hot water you use.

Your cylinder is very well insulated, so if you don't have cheap rate overnight, it doesn't really matter when you turn the elements on and off. The thermostat will stop using electricity as soon as the water reaches your target temperature. It will not constantly use electricity even if it is switched on (unless you have a leak)

Your cylinder looks quite big. Now that you've turned it off, see how long it takes you to use up all the stored hot water.

If you like long, powerful showers, your money is going down the drain.

Do you have an electric tumble drier?

Your £125 energy bill is not informative. Take the meter readings and see how many kWh you are using. Usually once a month is enough, but if you think you have a problem, take them at least once a day, preferably more, for a week to find out what your usage pattern is.

 

[Hakim92]

Oh okay so really I should probably change my energy to the 7 economy one? And from what I take it’s crucial I use the thermostat then

Sorry but is there a way I can check to see how quickly it’ll take? I’m on a night shift so will be having. A shower around 8am so I doubt there will be hot water by then

We have a washing machine with a drier setting which we have used a few times at the beginning but refrain from using.

Other thing could be is possibly the m energy company is taking readings from a different flat. A colleague told me that this happened to him in a new build and can be quite a common issue.

I’m just confused why it’s been so expensive when we essentially only use it for hot water barely use the heating.

Many thanks for your reply it’s helpful

 

[Hakim92]

The cost of heating your hot water is directly proportional to the amount of hot water you use.

Your cylinder is very well insulated, so if you don't have cheap rate overnight, it doesn't really matter when you turn the elements on and off. The thermostat will stop using electricity as soon as the water reaches your target temperature. It will not constantly use electricity even if it is switched on (unless you have a leak)

Your cylinder looks quite big. Now that you've turned it off, see how long it takes you to use up all the stored hot water.

If you like long, powerful showers, your money is going down the drain.

Do you have an electric tumble drier?

Your £125 energy bill is not informative. Take the meter readings and see how many kWh you are using. Usually once a month is enough, but if you think you have a problem, take them at least once a day, preferably more, for a week to find out what your usage pattern is.

Oh okay so really I should probably change my energy to the 7 economy one? And from what I take it’s crucial I use the thermostat then

Sorry but is there a way I can check to see how quickly it’ll take? I’m on a night shift so will be having. A shower around 8am so I doubt there will be hot water by then

We have a washing machine with a drier setting which we have used a few times at the beginning but refrain from using.

Other thing could be is possibly the m energy company is taking readings from a different flat. A colleague told me that this happened to him in a new build and can be quite a common issue.

I’m just confused why it’s been so expensive when we essentially only use it for hot water barely use the heating.

Many thanks for your reply it’s helpful

 

[Hakim92]

Turning them both off will certainly save you money ,but you won't ever have hot water !!
As your showers hot water comes from that cylinder you will need to determine how to use the immersion heaters. The more hot water you need ,the longer the immersion needs to be on each day. Besides showering ,you probably only need hot water for hand washing and dishwashing. I would suggest you use the immersion That is connected to the timer ,and set it to come on for an hour each day ,see how you get on. If you take very long showers and there are more than two of you ,that may not be long enough.
Not sure what the red isolation switch is for. Turn it off and see what doesn't work !!

Thanks for the detailed reply!

How long does the hot water typically last for?

 

[JohnD]

A 3kW immersion heater takes about 1 minute per litre. Once heated, your cylinder will stay hot for days, or until you use it. Each immersion heater has its own thermostat under the cap (though the cylinder might have one)

A shower might use 25 to 50 litres. A bath uses around 100 litres.

You can calculate your shower usage by running it into a bucket, timing it to full, and calculating litres per minute.

Then multiply that by minutes you take.

Some of the water will be mixed with cold.

 

[JohnD]

I’m just confused why it’s been so expensive when we essentially only use it for hot water barely use the heating.

We need to know your meter readings.

 

[oldbutnotdead]

Oh okay so really I should probably change my energy to the 7 economy one? And from what I take it’s crucial I use the thermostat then

Sorry but is there a way I can check to see how quickly it’ll take? I’m on a night shift so will be having. A shower around 8am so I doubt there will be hot water by then

We have a washing machine with a drier setting which we have used a few times at the beginning but refrain from using.

Other thing could be is possibly the m energy company is taking readings from a different flat. A colleague told me that this happened to him in a new build and can be quite a common issue.

I’m just confused why it’s been so expensive when we essentially only use it for hot water barely use the heating.

Many thanks for your reply it’s helpful

Your bill will have a meter number on it (usually letters in the number as well) Check your actual electricity meter, make sure the number matches the one on your bill.
Also check your tarriff. You may still be on one with a very high unit charge but no standing charge (as a landlord I make this change between tenants to keep costs down during voids between tenants as well as ensuring that the new tenant isn't chased for money owed by the previous tenant).
If your flat is in a block, make sure your meter isn't supplying someone else's flat or any communal facilities (corridor lights, outside lights etc).
Way to check (preferably one evening when you're not busy and other people are home) switch off EVERYTHING in your flat, read the meter, wait for at least an hour, ideally 3 or 4 hours then reread the meter. It shouldn't have changed- if it has then start investigating.

 

[JohnD]

Sorry but is there a way I can check to see how quickly it’ll take? I’m on a night shift so will be having. A shower around 8am so I doubt there will be hot water by then

A 3kW immersion heats about 1 litre per minute. So from totally stone cold, about an hour and a half for a bath. Less if it is already partly hot.

An Economy 7 tariff could heat over 400 litres during the night, if you had such a huge cylinder.

Washing up, maybe ten minutes, but such small amounts may seem to take longer, because it will start by heating a larger amount to a lower temperature.

I don't know how much water you use in your shower.

 

[ianmcd]

Other thing could be is possibly the m energy company is taking readings from a different flat.

your bill has the meter serial number on so make sure that matches your meter

 

[Hakim92]

Hi all,

Sorry with the delay but I think I know where some of my problem is.

The heatrae control panel was set far too high and I lowered it down with a screw driver. Person I spoke with on the phone from heatrae said thatll help reduce the bill but said I still need to reduce the thermostat in the cylinder.

I can’t locate the thermo in the cylinder though.. do you guys have any idea?

I have also found from monitoring my daily usage is that we get a spike after midnight. The thermostat has been set to 0500-0700 although I don’t see a spike in electricity use there. So something is not right.

Thank you guys

 

[ianmcd]

Hi all,

Sorry with the delay but I think I know where some of my problem is.

The heatrae control panel was set far too high and I lowered it down with a screw driver. Person I spoke with on the phone from heatrae said thatll help reduce the bill but said I still need to reduce the thermostat in the cylinder.

I can’t locate the thermo in the cylinder though.. do you guys have any idea?

I have also found from monitoring my daily usage is that we get a spike after midnight. The thermostat has been set to 0500-0700 although I don’t see a spike in electricity use there. So something is not right.

Thank you guys

the Heatrae as you call it is for your radiators, has nothing to do with the Hot water, the temperature of the water is controlled by the immersion thermostats, turn the power off and remove the caps on the immersion heaters the thermostat is under there