How much is your pilot light costing you?

4legsbetter

I have a Vaillant "heat only boiler", ie there's a hot water cylinder in an airing cupboard (wasting heat), and central heating. I think it's a VC GB 182 EH model - it could be the 242 EH or 282 EH, but the number of radiators would suggest it is the smaller (18KWh one). The previous owners from 6 years ago, left the user manual, but there is no identification on the boiler itself. It was installed in July 1994.

It is burning the equivalent of £15.00 a month when neither the water or central heating is on, so this presumably, is for the pilot light alone.

I am considering changing to a Combi type boiler because:

1. My boiler is stated as being only 72% efficient
2. If a combi boiler does not have a pilot light I could save £15.00 per month
3. In summer, when we only use hot water, we won't be having the boiler running for an hour a day, just to heat the water in the hot water cylinder in the airing cupboard.

By the way, I have just installed a wood burning stove, and this is making quite a difference already - I spent £15.00 on wood which is lasting months (same as keeping the pilot light going for 1 month!).

My questions are:
1. Do Combi boilers have a pilot light - if so, would it cost £15.00 a month?
2. Apart from removing the hot water cylinder etc, which I can do, what plumbing work would be required in addition to swapping the boiler - I wouldn't want to have to have pipes up under the floor as I have just put laminated flooring down . . .

Premier_2

abakewelltart wrote: »

I have a Vaillant "heat only boiler", ie there's a hot water cylinder in an airing cupboard (wasting heat), and central heating. I think it's a VC GB 182 EH model - it could be the 242 EH or 282 EH, but the number of radiators would suggest it is the smaller (18KWh one). The previous owners from 6 years ago, left the user manual, but there is no identification on the boiler itself. It was installed in July 1994.

It is burning the equivalent of £15.00 a month when neither the water or central heating is on, so this presumably, is for the pilot light alone.

I am considering changing to a Combi type boiler because:

1. My boiler is stated as being only 72% efficient
2. If a combi boiler does not have a pilot light I could save £15.00 per month
3. In summer, when we only use hot water, we won't be having the boiler running for an hour a day, just to heat the water in the hot water cylinder in the airing cupboard.

By the way, I have just installed a wood burning stove, and this is making quite a difference already - I spent £15.00 on wood which is lasting months (same as keeping the pilot light going for 1 month!).

My questions are:
1. Do Combi boilers have a pilot light - if so, would it cost £15.00 a month?
2. Apart from removing the hot water cylinder etc, which I can do, what plumbing work would be required in addition to swapping the boiler - I wouldn't want to have to have pipes up under the floor as I have just put laminated flooring down . . .

Are you sure you have done your sums correctly? Pilot lights do cost money, but yours is costing about 2-3 times the typical if your figures are correct.

Anyway, at £15 per month, thats £180 per year.
A new boiler is going to cost you at least 10 times that amount,(perhaps much more) so changing it in an attempt to save money wouldn't be the wisest investment of such money.

macman

Why do you specifically want a combi to replace your existing boiler? A modern condensing conventional boiler is just as efficient as a combi. No modern boilers have pilot lights.
If the hot water tank is properly lagged, the heat loss is minimal. And it's not wasted-it still heats your house.
If you want a combi, then you must first establish that your water supply (flow and pressure) is sufficient for one, and that your gas supply pipes are similarly adequate for the demand. That can only be established after a site survey by a GSR RGI.
As Premier says, the payback based on piiot light costs alone simply don't add up.

Cardew

There have been several threads on Pilot lights - one recently - and none give costs anything like as much as your figure of £180 pa.

Could you be using the Tier 1 cost of gas in your calculation?

macman

abakewelltart wrote: »

I have a Vaillant "heat only boiler", ie there's a hot water cylinder in an airing cupboard (wasting heat), and central heating. I think it's a VC GB 182 EH model - it could be the 242 EH or 282 EH, but the number of radiators would suggest it is the smaller (18KWh one). The previous owners from 6 years ago, left the user manual, but there is no identification on the boiler itself. It was installed in July 1994.

It is burning the equivalent of £15.00 a month when neither the water or central heating is on, so this presumably, is for the pilot light alone.

I am considering changing to a Combi type boiler because:

1. My boiler is stated as being only 72% efficient
2. If a combi boiler does not have a pilot light I could save £15.00 per month
3. In summer, when we only use hot water, we won't be having the boiler running for an hour a day, just to heat the water in the hot water cylinder in the airing cupboard.

By the way, I have just installed a wood burning stove, and this is making quite a difference already - I spent £15.00 on wood which is lasting months (same as keeping the pilot light going for 1 month!).

My questions are:
1. Do Combi boilers have a pilot light - if so, would it cost £15.00 a month?
2. Apart from removing the hot water cylinder etc, which I can do, what plumbing work would be required in addition to swapping the boiler - I wouldn't want to have to have pipes up under the floor as I have just put laminated flooring down . . .

If by this you mean that you are not using the boiler for hot water in the summer, but an immersion heater instead, then you can turn off the pilot light for the months when the heating is off. So your £180pa becomes more like £90pa. However this will cost you much more due to the 300% higher cost of heating hot water by electricity than gas, so is not recommended.
If you are heating your hot water all year round by gas, how can you quantify that £15pm of that is spent on burning the pilot light?

ollski

They used to say an average pilot light used about 50.00 p.a, but that was a few years ago. It could easly be that much though, there is a huge difference between one pilot and another and how they are set and adjusted.

st999

I have 2 pilot lights, one for heating, the other for hot water.

The hot water one uses 3 kWh of gas a day and the heating one 5 kWh a day.

Based on the hot water being on all the time and the heating on for 7 months of the year that is a total of 2180 kWh, with my gas costing approx 4p per kWh that is £87.20 per year for gas.

And during the 5 months when I don't need heat that is nearly £20 wasted on heating a house that doesn't need heat.

And considering that the pilot light for the heating doesn't heat the house by any significant amount that is wasted also.

Same for the hot water pilot light.

So nearly £90 a year out of £600 wasted on pilot lights because any heat produced by these pilot lights is immediately blown out the outsized necessary ventilation grill.

I just wish my 21 year old warm air heating would blow up so I would have an excuse to replace it.

Just joking :rotfl: the replacement warm air heating still has pilot lights according to Johnson and Starley :eek:.

4legsbetter

Thanks very much for all replies.
The reason I thought a Combi boiler would be more economic is that you only heat the water you use. In order for me heat say, 2 litres of water, I would need to heat up a whole cylinder of water (with gas), so that doesn't sound very economic to me!

Re the maths, I have just done another reading, and it's worse!
Smart meter reading today at 8.20am - 3426.500.
Reading at 1.30pm - 3426.822 - that's 0.322 cu m of gas used.

Central heating and hot water have not been on, although the boiler is warm (with door open), suggesting the gas has been burnt (the pilot light?) and not leaked.

0.322 cu m gas used in 5 hours is 1.5456 cu m in 1 day.
So for 1 month (x 30) it's 46.368 cu m.
Convert to KWh (x 11.192 is same as First Utility's correction factor of x 1.02264 then calorific value x 39.4 / 3.6)
This gives us 518.95 KWh

Then at 3.71p per KWh we get 19.25
Plus vat at 5% = £20.21

Thats for 1 month!!

Canucklehead

Are you sure you have a permanent pilot on this boiler?
VC GB 182 EH


Canucklehead.

macman

But once you have a tank of hot water, it will keep hot all day if the tank is properly lagged. Are you seriously saying that your hot water requirement is only 2 litres per day?

ollski

Canucklehead wrote: »

Are you sure you have a permanent pilot on this boiler?
VC GB 182 EH


Canucklehead.

That's true, electronic ignition. It does have a water preheat function though, that would be much more likely to contribute to your gas bill.