Electricty used by gas heating

jrawle

@MikePh it's probably best to wait for your smart meter installation, then you can see whether the usage really goes up when your heating is on. It would be good if you can report back as it would be good to know the outcome, or if you are still none the wiser, we can try to give further suggestions.

Sorry if it adds me to the list of clowns, but as a professional physicist, I realise lots of people are confused about units of electricity. I can see why, so I cast no aspersions.

Physicists actually use the joule (J) as the unit of energy, but this is a very small amount. You'll also see it on food packaging as an alternative to calories. In physics terminology, "power" is the rate at which energy is used. For this, we use the watt (W). One watt means you are using one joule of energy every second, in other words 1 W = 1 J/s. So an old 60W light bulb uses 60 joules of energy every second.

The confusion arises because the joule is such a small unit of energy, and a second a shorter time period than most people care about. That is why it is common to use the kilowatt-hour as a unit of energy. That is the amount of energy used if you run an appliance with a power of 1 kilowatt (1000W) for an hour. A kWh is therefore equal to 3.6 million joules.

Instead of  kilowatt-hours and watts, try thinking in joules and joules-per-second. Then it's easier to understand the difference. Then remember that a kilowatt-hour is 3,600,000 joules, and a watt is a J/s, and you'll see why they are that way around.

I hope that's useful for anyone who is confused, although maybe introducing yet more units will have caused more confusion.

QrizB

This might be futile but trying to get back on track ...

MikePh said:

My maths told me that because of switching on and off, the monthly spend should be more like £2 per month additional.

Could the pump be faulty? could that cause the high use?

My central heating circulation pump, like most others in this thread, uses around 100 watts when it runs. Exactly how long it runs for will depend on a lot of factors but it shouldn't be running continuously.

• If it runs for 5 hours, it will use 500 watt-hours (half a kilowatt-hour).
• If it does that every day for thirty days, it will use fifteen kilowatt-hours.
• Electricity currently costs around 20p per kilowatt-hour, so those fifteen will add £3 to my bill for the month.

OP if your central heating is really using 4 kilowatt-hours per day it must be doing more than simply running a circulation pump.

MikePh

Hey    Thanks jrawle
No you are certainly not one of the clowns, I know when somebody is  trying to help.  Thanks
My degree is also in physics

All I want to do is find out what is eating my, erm, hold on, power?

QrizB
Thanks for "back on track"
Yup. Thats what I reckon should be happeneing. Maybe 15 kWh per month. but it is 150 +

Hi DerwentMailman
My measurements compare one day in December with the next day in December.
One day heating on, one day heating off (mrs not happy wearing two jumpers)
I have no tumble dryer, I have no dehumifier, I have no electric blanket, I never change the spin speed on washing machine

zagfles

jrawle said:

@MikePh it's probably best to wait for your smart meter installation, then you can see whether the usage really goes up when your heating is on. It would be good if you can report back as it would be good to know the outcome, or if you are still none the wiser, we can try to give further suggestions.

Sorry if it adds me to the list of clowns, but as a professional physicist, I realise lots of people are confused about units of electricity. I can see why, so I cast no aspersions.

Physicists actually use the joule (J) as the unit of energy, but this is a very small amount. You'll also see it on food packaging as an alternative to calories. In physics terminology, "power" is the rate at which energy is used. For this, we use the watt (W). One watt means you are using one joule of energy every second, in other words 1 W = 1 J/s. So an old 60W light bulb uses 60 joules of energy every second.

The confusion arises because the joule is such a small unit of energy, and a second a shorter time period than most people care about. That is why it is common to use the kilowatt-hour as a unit of energy. That is the amount of energy used if you run an appliance with a power of 1 kilowatt (1000W) for an hour. A kWh is therefore equal to 3.6 million joules.

Instead of  kilowatt-hours and watts, try thinking in joules and joules-per-second. Then it's easier to understand the difference. Then remember that a kilowatt-hour is 3,600,000 joules, and a watt is a J/s, and you'll see why they are that way around.

I hope that's useful for anyone who is confused, although maybe introducing yet more units will have caused more confusion.

I blame New Labour and their dumbing down of the Physics GCSE

But yes it is confusing having units of energy expressed as units of power x units of time, it's a bit like measuring distance in units of speed x units of time. Although having said that, it is done, eg light years!

MikePh

"I blame New Labour and their dumbing down of the Physics GCSE"

OK zagfles, that puts you back in my good books

Sailbad

Surely it's not possible to have a degree in physics and not understand the difference between kW and kWh?

MikePh

no it isnt

Oneye12

As an Electrical Engineer can I suggest for now you stop meter readings with associated calculations {for now}.

It is a rare event but the only device that can give the original symptoms is the central heating pump.
Many years ago mine, as part of a hybrid system and fused separately blew the fuse. ‘Upping’ the fuse size meant it would run again but taking excessive current. This is caused by partial short circuit windings. Didn’t burn out because it’s water cooled, although you might say they run hot anyway.
The op needs to see if the pump is faulty and get it replaced PDQ before it does burn out {and assuming it is not fused separately}.

Now the calculations - mine was fused at 1amp {quick blow} which means it was drawing over 240watts {on a 240vAC supply} to melt the fuse. The pump was rated around 100watts.

MikePh

@Oneye12

Exactly,   the only difference in the readings is that the central heating is on or off

smart meter should help find out what on earth is going on here

bagand96

MikePh said:

Thanks for that rapid reply  jrawle

Worcester Greenstar Ri  Condensing boiler

Yes, the thermostat is indeed turning the system on and off.

The readings are a direct comparison beteen heating on and heating off, nothing else has changed (and every light is low energy anyway)

My maths told me that because of switching on and off, the monthly spend should be more like £2 per month additional.

Could the pump be faulty? could that cause the high use?

(typo edit)

I'm not familiar with boiler models, but a quick Google suggests that isn't a combi boiler so I'm guessing you have a hot water tank?  Is there a chance that there's an immersion heater that is inadvertently being switched on when the heating is?