Gas Central Heating

[barry1010]

My boiler is 40 years old and is still going strong. It uses about 13kw per hour - is that good, bad or average?

[Vagus]

I don’t know how this compares, Barry, but in February we used on average 45kw of gas a day for heating and hot water, both retired so home a lot.
Our boiler is about six months old, a combi.

[Old_Geezer]

It'll get converted to heat one way or another. If you are using it to remain comfortable then that's what you need.

[Gizmonster]

Can I ask - where do you get the figure of 13KW per hour from?
Do you work it out from your bill/usage etc, or is that its official usage?
I'm asking because we have a Main Combi 30 Eco and its official usage is 28.63 KW per hour. This is what it would use if it ran constantly for an hour, but it never does because as it gets the radiators up to the required temperature, it then turns off and comes on intermittently as it maintains the heat of the radiators.
If your figure of 13KW per hour is correct, I personally would say it's quite good, especially as it's as old as you say - if my boiler ran for 30 minutes per hour it would be using around 14KW per hour.

[barry1010]

Biz, I have a smart meter and my Ovo app tells me how much gas and electricity I use each hour. My central heating is turned off overnight but if I have to be up for a while I put it on an hours boost. That isolated hour tells me exactly how much gas I’m using. It heats the hot water at the same time.

[Karamia]

Just got my bill for Feb and we have used 1102 kwh gas for 28 days which works about 39kwh a day for heating n hot water during Feb.
Had Combi boiler for about 5 years.
Bill shows we average 20kwh gas per day for year overall.

[barry1010]

Thanks all for the replies. We also use gas fires during the day, we are trying to heat only the rooms we are using

[barry1010]

That’s excellent, Karina. How long do you have the c/h on a day, on average?

[Karamia]

It never drops below 16 C day or night so is technically on low all through night but I turn up higher for a couple of hours in morning and then for around four or five hours evening.

[Atheist]

Kw is a measure of the power use. Kwh is a meaure of energy use equal to the Kw multiplied by the time the Kw are 'flowing'.
Imagine that the gas is water flowing from a tap. The Kw tells you the rate of flow, but not the total amount of water that has flowed.
If the boiler burns gas at the rate of 10Kw for an hour, then the energy used is 10Kwh.
A bit esoteric, but I thought it worth mentioning.

[Etch]

That's pretty much the same as my 35 year old Potterton Netaheat Electronic, barry1010. When its burners are lit mine uses gas at a rate of 0.92 imperial units per hour, which corresponds to its 29kW rating. The on/off cycling to maintain the set boiler temperature means that it typically uses 0.40 imperial units in the first hour after the central heating comes on (and doesn't get turned off by the room thermostat), so about 13kWh per hour.

[barry1010]

Etch, you've got the same boiler as me

[ABerrant]

Similarly, my 36 year-old Thorn EMI (Myson) Apollo burns around 1m³ of gas (11Kw) per hour.

[Atheist]

The energy used is affected by
1 outside temperature (not controllable)
2 inside temperature (controlled by room stat and/or rad stats)
3 level of insulation (including draughtproofing, and your thermal underwear)

If you are well insulated and use the lowest room stat temperature you are comfortable with, you'll minimise the energy use.