Weighing up the comparative costs of two home-heating options

[AL_n]

Hello all,

I'm trying to determine the cost-benefits (if any) of installing a regular combi-boiler central heating system in my 3-bed semi. The pipework has already been installed by a previous owner. All I need to do is buy a boiler hand get it plumbed in. I can istall the rads myself. I already have some rads. The boiler will be sited very close to an existing 25mm gas supply pipe.

It looks like I could obtain an A-rated combi boiler plus flue kit for under £500 (Lamborghini Extrema 30C for example). I already have some radiators I can use.

The alternative method of heating the house would be to use electric fan heaters, switched on manually, in any room I happen to be using at any time. I am the only resident.

I think it's safe to assume that electrical heating will continue to be more expensive than gas over the next decade, however, the fan heater option means I am only heating one room at a time.

Regarding heated tap-water, I am currently using an immersion heater, switching it on manually, for one hour before I need to take a bath or shower. If I installed a combi boiler, I would no longer need to use the immersion heater.

Can anyone give me any clue as to how long it would take to recoup about £700 in saved fuel costs if I install the gas-fired C/H system?

Many thanks!

Al

[Andrew Gabriel]

What is your current annual electricity consumption, in kWH and in money?

[John Rumm]

Not with the information you have presented so far...

We would need to know what the thermal efficiency of your house is like. How warm you keep it, what your occupancy level is like etc.

How are you heating it at the moment? What is that costing?

Are you only interested in the lowest possible cost, or is comfort / ease of use / controlling damp an issue?

[AL_n]

[e-mail] (Andrew Gabriel) wrote in news:k0j5pd$f1j$2 @dont-email.me:

My KWH consumption over the past year is: Electricity: 2360 KWh:Cost=£347 inc vat. Gas: 2554 KWh:Cost=£116 inc vat.

Many thanks,

Al

[Owain]

But losing heat through uninsulated internal walls to the adjacent unheated rooms.

Don't know, but I think it's fair to assume you will add more than =A3700 to the value of the house, immediately.

Does your existing HW cyl. have a coil for indirect use from a boiler? Then you woudn't need to buy a combi and could get a (probably cheaper and more reliable) condensing non-combi boiler, and keep the immersion for backup/emergency use.

Owain

[AL_n]

John Rumm wrote in news: [e-mail]:

The thermal efficiency of house is not great. It has 12" of loft insulation but half of the house was built in 1850, of solid stone. The other half of the house has cavity walls, but with only 1"-thick sheets of polystyrene in the cavities as insulation. Only 50% of the house's windows are double- glazed.

I spend about 75% of my time at home. As mentioned, I have been heating the house with electric heaters, warming only the room I happen to be in at any particular time.

The house doesn't really have any significant damp problems.

Cost of heating is the main factor I'm concerned with. To me that's more important than living in optimum comfort, (say, with the hall, landing and bathroom continuously warmed).

My KWH consumption over the past year is: Electricity: 2360 KWh:Cost=£347 inc vat. Gas: 2554 KWh:Cost=£116 inc vat.

Thanks,

Al

[Phil L]

Expect to use twice the gas and half the leccy and it won't be far off, when I used to run my combi [1], that's what mine was, although my house is well insulated, but the DG is ineffective.

[1] I used to warm the living room, hall (which heated the landing too) bathroom and 1 bedroom, so 4 rads (from 9) were getting warm, doors kept shut to the other unused rooms. This is before I got a woodburner, which now warms the living room, and the heating doesn't get turned on at all except for maybe a week or two if it stays well below freezing long enough....last winter I used a quarter of the gas I'd used the winter before

[Harry Bloomfield]

AL_n wrote on 16/08/2012 :

Have a chimney and have you considered the possibility of a wood burning stove?

[AL_n]

Owain wrote in news:e65d4ae4-8d21-4aa3-a92c- [e-mail]:

Yes, I guess so.

Yes - that is a good point. However, if that were the only reason for doing it, I'd probably install it just prior to selling the house. (Money is tight at present; whatever I do will be on borrowed money at about 8% APR.)

That's a good suggestion - thanks. I think the immersion tank does have connections that are not in use, so perhaps that's what they are. I must say, my previous experience of combi boilers was a frustrating one. Annual maintenance cost me a lot and I envied people who had older system boilers that never needed any attention.

Thanks for the input,

Al

[AL_n]

"Phil L" wrote in news:S4bXr.859139$ [e-mail]:

Thank you.. That's the kind of rough guide I was looking for.

Do you mean you saved 75% on your gas bill just by installing the wood burner stove?

I have considered getting a wood-burner stove, but I'd have to pay for firewood (or coal) most of the time. I didn't think that was a cost- effective way of producing heat, compared to gas..

Regards,

Al

[AL_n]

Harry Bloomfield wrote in news: [e-mail]:

Thanks for the suggestion. I don't currently have a chimney. (Actually, I have a chimney breast, but it only goes up as far as the loft!) I did once consider installing a wood/coal-burning stove, but I'd have to pay for firewood (or coal) and I didn't think that was a cost-effective way of producing heat, compared to gas.

KR's

Al

[Andrew Gabriel]

= 14.7 p/kWh

= 4.5 p/kWh

If you managed to move all your electric consumption to gas at 90% efficiency, that would add £118 to the gas bill and save £347 on the electric, giving a saving of £229/year.

Obviously that's not realistic, but you can't do better than that, and in reality, you'll probably get half that, say £115/year.

You mentioned a loan, and I'll guess you won't be able to do this for under £1000, which is £80/year interest alone, plus whatever you pay off the capital.

This is a very crude calculation, ignoring stepped rates or standing charges, etc, but if you're looking at it purely from the cost saving perspective, it's not really worth it, certainly when you add in boiler maintenance and replacement charges.

BTW, what do you currently use gas for, just cooking?

[Owain]

Could be worse.

The new boiler will only use gas when it's turned on. With TRVs (thermostatic rad valves) you can turn down the unoccupied rooms to low (but not freezing) and with a programmable stat you can set different temperatures for different times of day. With a lower level of even heating you won't be tempted to over-compensate by cranking up the fan heater.

Except for the depths of winter I find 30 mins central heating morning and evening adequate. It certainly doesn't get run continuously!

The bottom line is that gas is about a third the cost of lecky.

It might be worth checking the energy saving trust website in the slim possibility you're entitled to a grant or something.

Owain

[Phil L]

Yep. the living room is toasty warm even in the depths of winter, but the upstairs is quite chilly, the general rule is 'dress approproately' IE don't lounge around in shorts and tee-shirts in December :-p I'd rather sleep in a cool bedroom than a warm one anyway

I bought 3 bags of coal last November (only got the burner in October) and I've still got one left unopened, I burnt structural timbers [1] last winter and a few logs I purloined here and there but I didn't buy anything other than the coal, which was used only rarely.

[1] I and several others in my family are builders, so all decent thickness timber, like 4X2 and bigger got sawn into 12in logs and burnt, likewise 17 fence panels, 12 mahogany window frames, two cherry trees and a telegraph pole, along with a t&g shed, half a dozen door frames and various other bric-a-brac.

It's time consuming for me because I live about 50m from where I can park my car, so a bit of a trek to get timber to the back garden, but once it's there, 3 or 4 hours with a table and chop saw combi and I've enough firewood bagged for the week ahead, that said, I intend using more coal this winter as it lasts longer and at £7.50 for 25kg it's cheap enough...might go and get a few bags this weekend actually to get a bit of a stock on.

[The Natural Philosopher]

to be fair this would be my experience also if the house wasn't too damned big. The aga - about 600-900W continuous heats most of the house more than adequately for 9 months of the year, and a wood burner heats the bedroom for the 3 cold winter months. I use the CH to keep the rest above 10C.

The childhood home had no insulation and was heated solely with a single coal fire and back boiler.

Tepid baths once a week were the norm.

[Phil L]

We had a canon gas fire in the living room and that was the only source of heat in the house, prior to the smokeless act coming in, we too had a coal fire back boiler, but it only warmed the water in the tank, we didn't have radiators.

Ice on the inside of windows was commonplace then, and I can remember my dad insulating our loft when I was five (42 years ago!) with the new fangled fibreglass insulation he got from work (they made it and give all workers free rolls) at the reccomended thickness of one inch - it was still there when I insulated it 20 years later with the new standard thickness of 100mm

[AL_n]

[e-mail] (Andrew Gabriel) wrote in news:k0jge4$nk9$ [e-mail]:

Thanks, Andrew. Yes, a crude calculation is all I was hoping for, so the above is helpful - thank you.

I use a gas cooker. There is also a radiant gas fire in my lounge. I installed that gas fire last winter, hoping it would kick out enough heat to warm the whole house and save me £££ on electric bills. Unfortunately, it doesn't, especially during the coldest months. I don't actually use the lounge much (1/2 hour a day). I spend most of my time in my study, upstairs, which is cheap to heat due to its small size. I have a fan heater with a thermostat, under my desk, pointing at my feet, which works quite well.

I keep hoping that electricity will end up cheaper than gas, after they build more nuclear power stations, but who can tell?

Regards, Al

[John Williamson]

It will always be cheaper than wind and solar, but whether it becomes cheaper than gas per unit of heat will depend on whether the anti-nuclear lobby give up. Until they do, we will have to continue burning fossil fuels to make electricity in the quantities demanded by the end user.

Burning fossil fuels to make heat to generate electricity to make heat where you want it can't possibly be as efficient as burning it directly, all things being equal. Transmission losses alone will see to that.

[AL_n]

Owain wrote in news: [e-mail]:

That does seem to be a factor worth considering.

That's a good point. I will check.

Many thanks for your helpful input.

Al

[The Natural Philosopher]

So buy nuclear energy from EDF then. Cheaper anyway.