Pilot light gas consumption?

[John]

Out of curiosity I calculated how much gas my boiler pilot light consumed and took a meter reading at 9pm and again at exactly 9pm the next day. The heating & water have been off all that time with just the boiler pilot light lit. I included the 2 red decimal numbers in the meter readings and in 24hrs it had used 0.18 unit, which over a year is

65.70 units. If my sums are correct (Calorific Value of 39.4) I work that out to be around 2081kWh. Is that amount of consumption about right for a pilot light? On 2p per kwh that would be around £41 a year. The boiler is a Potterton Prima B about 6 years old.

[Ben Blaukopf]

3-5/month, so it sounds like you're bang on.

Ben

[mrcheerful]

Some friends of mine had their gas meter run out of money on a regular basis (and electric) The meter let through enough gas for a pilot light. They always had a kettle over the pilot light on the stove or a pan of stew, they lived like that for years, so yes even a tiny flame is a significant number of btus per year.

mrcheerful

[Dave Plowman (News)]

Remember not all that energy is wasted unless you never use the boiler. Some of it will go towards keeping the heat exchanger warm, and in cold weather help to heat the room.

[Bob Eager]

for a Netaheat!

[Dave Plowman (News)]

I'm surprised to find any boiler this recent using a permanent pilot light.

[manatbandq]

The same is true of all the "wasted" energy from all those filament light bulbs, TV and video left on standby, wall warts left plugged in and switched on, etc, etc. If you really want to save energy, turn the thermostat down or wear an extra layer of clothing.

MBQ

[Ed Sirett]

around 240W - plausible.

[Ed Sirett]

I reckon on this being allowed for in comparisons. The 'book' figure for a permanent pilot is a -5% on the SEDBUK rating of the boiler.

[T i m]

We currently have no 'central heating' in this 1897 house and (these days?) only have the gas fire on in lounge in the real winter and even then only ever one of the 3 burners (possibly assisted by electrical kit as mentioned elsewhere )

A small storage rad in the (newish) bathroom 'airing cupboard' seems to keep that comfortable and a bigger one in the main bedroom (both electically 'on' 24/7) only come in when needed (economy 7).

My daughter is in the box room (3 exposed solid 9" brick walls) has a tiny balanced flue wall heater that will have her room like a sauna in a few mins.

The middle bedroom holds the Aircon unit that may get used more as the heating gets used less .. hmmmm?

'She's' going through 'the change' (single men, don't ask ..) so to manage that I would need to fit a climate contol system that could change the temperature in the room from -5 to plus 20 deg C and back in 30 seconds ...? ;-(

All the best ...

T i m

[John]

Well I'm due a boiler service soon so I'll ask them to give the pilot light a good once over and to check that the flame is within the manufacturers spec. That might save me a fiver a year which I can put towards a litre of petrol :)

[Pete C]

Over 15 years that could pay for a condensing boiler....

cheers, Pete.

[Dave Plowman (News)]

But the calculation is flawed by making it at this time of the year with the boiler not in use. For the 6 months or so of the year when the heating is needed - or it's used for just heating hot water - all that energy won't be wasted. There's probably a diversity calculation that takes this into account.

[John]

Ah, so during the time the boiler is in use the pilot light will be going towards heating the boiler and not wasted. Now I feel a whole lot better, cheers.

[Dave Plowman (News)]

Even when the boiler isn't actually firing, some of the energy from the pilot light will help keep the water inside it warm for when it next does.

However, it's a less than ideal device. Obviously, some means of lighting the boiler on demand should be better. Assuming it has a long life and doesn't cost more in replacements than the energy it saves. ;-)

My real point is that some adverts quote the sort of figures you did and suggest you'll get those savings without one. Drivel would be proud of them.

[Pete C]

What happens when the pump is running but the boiler isn't firing on an old style boiler, I'd have thought there are convection losses up the flue? Maybe worth another condensing boiler over 15 years...

cheers, Pete.

[Ed Sirett]

For sure. This is the biggest _single_ item in the older designs that impacts efficiency.

[Doctor Drivel]

Yep.

8760 hours in a year. A boiler is firing for about 10% of that time, if that. So, 90% of the time the pilot is not needed and a waste heating the outside, and adds nothing. So, £37 per year for 10 years is £370, probably a lot more as gas goes up in price. Which more than pays for a condensing boiler. Anyway you have to fit condensers anyway.

[jackpona]

Is it possible to convert a satanding pilot to an electronic type

-- jackpona

[John]

Yes but without design approval and testing its illegal