Old boiler consumes unbelievable amount of gas

AndyPK

As you said, I would be in no rush to remove a working Vaillant.
They just want money out of you. I'm not sure how combi's cope with a house like yours in any case. Could be a big mistake!

Don't you find you are sweating in summer with the aga on? Is there room for a small electric cooker for use in summer? Would that work for you?

ianna_2

Cardew, indeed we have an imperial gas meter, but it is stated on the bill they convert it to metric:

units 1396 (for example) x volume correction 1.0) x metric conversion 2.83 x calorific value 39.2 and divided by 3.6. It gives 43,992, unfortunately, as they state.

ianna_2

Andy, I agree that they want money - last time (several years ago) they wanted around 5000 for the installation of a new boiler! What economy should it make if they don't last?

It's a good idea with AGA, thank you!

matelodave

You'd get a better return on sorting out the controls, insulation and how you use it all rather than just replacing the boiler. £3k+ to change the boiler would require a saving of at least £300 a year to pay back in 10 years, even more if you've got to borrow the money to do it.

If I were you I'd really try and work out what's using it all and do something about it. There must some efficiencies you can make in how you heat the place, heat the water and do your cooking.

Keeping a water tank hot all day & night probably isn't necessary and if it's gravity fed and hot water is circulating around the system all the time through uninsulated pipes and a poorly insulated tank then there's lots of heat being wasted.

It's not unheard of to get reverse circulation (we had it in a previous place) where all that lovely hot water got dispersed overnight though the plumbing & boiler so it all had to be heated up again the next day.

Lots of insulation on the tank and the pipework together with a motorised valve + tank stat (on the return leg) halved our gas consumption during the summer.

Installing some heating controls, where there were non, halved it in the winter as well. AFAIK the old boiler is still working 30 years on. A few TRVs made it even better.

CashStrapped

I would concur with a lot of the comments above.
You need to confirm and measure the usage from each appliance.

As a very rough frame of reference, I have a 35+ year old boiler it is reliable as hell but the price is efficiency.

For my 3 bedroom semi, with single glazed windows, cavity wall insulation and moderate loft insulation, I have got my usage running at around 24000kwh per year currently. It used to be higher, but I have tweaked how I use it. We have also had warm winters for the last few years.

So if you boiler is only 20 years old, something does sound very wrong.

As others have said

victor2

ianna wrote: »

victor2

1) The heating is always on - we didn't do it when we moved it but now we have 2 kids, so we don't switch the boiler off. We have a main thermostat - would radiator valves help?
2) it is serviced annually and every time I'm told it's not efficient, let's replace it with a new one. But I heard so many stories about new boilers - they don't seem to last!
3) Aga is always on and it works on gas, yes.

reeac, they keep on saying we have to replace it as it's not efficient although some of the engineers advise not to do that while old boiler works because new ones don't last long.

matelodave,

Aga is the only appliance heating the water! I'll check how it is controlled, I'm sure it uses gravity, not pump.

We don't have room thermostat, just a main one. It is on 20 degrees but that's max it can warm up anyway. Single glazing, loft is insulated, hot water tank and pipes are not insulated, I'll take care of it, thank you!

Cardew, we'll check! We moved from BG to Scottish Hydro as soon as we moved in, a mistake could happen... oh, gosh!

chanz4, I'll check what AGA it is, but several years ago an engineer replaced its insides. I think, it's about 15 years olf at least. It's a 2 ovens aga. One oven has 200 degrees, another one - 100 degrees.

C_Mababejive We have Vaillant GB 242E boiler.

It does sound like it's a combination of both the heating and Aga being on all the time.
As long as the boiler is working OK (which it probably is), keep it. The cost of replacing it with a modern condensing one will doubtless be higher than any savings you'll make over the life of the replacement - which will be considerably less than good old simple non-condensing ones!
If you can get TRVs fitted to all the radiators, except the one nearest the main thermostat, that will give you much better control over the heating. You just set them very low in areas not used so much. They are not expensive in themselves, but it is well worth getting them all done at once, as it involves draining the heating system.
You don't need the heating running when everybody is in bed, so set the boiler's timer accordingly. Having the heating come on an hour before people arise is generally more than enough to be comfortable.
Double glazing may not be viable, but at least use heavy curtains and seal any draughts to minimise the heat loss.

I don't know what controls the Aga has over the hot water, but a well insulated tank will only need heating for an hour or so before baths/showers and than maybe warming up again 12 hours later.

Pincher

ianna wrote: »

Cardew, indeed we have an imperial gas meter, but it is stated on the bill they convert it to metric:

units 1396 (for example) x volume correction 1.0) x metric conversion 2.83 x calorific value 39.2 and divided by 3.6. It gives 43,992, unfortunately, as they state.

I think you need to say you checked the actual meter, which says ft3, for cubic feet = Imperial, and not m3, for metric. What you seem to be saying is you looked at the statement, which says Imperial.

matelodave

I'm struggling a bit to understand your set-up. The Vaillant 242E is a combi-boiler (we had one in our last house) so I cant work out why you have an AGA on 24hrs a day heating hot water and have a combi that heats it on demand.
More info on your set up is required - our Vaillant boiler was pretty economical and is still going strong after 20 odd years. You wouldn't get any appreciable savings by getting rid of it. I'd be looking at the AGA as the source of your excess consumption together with a lack of controls on the central heating.

beardiedog

CashStrapped wrote: »

I would concur with a lot of the comments above.
You need to confirm and measure the usage from each appliance.

As a very rough frame of reference, I have a 35+ year old boiler it is reliable as hell but the price is efficiency.

For my 3 bedroom semi, with single glazed windows, cavity wall insulation and moderate loft insulation, I have got my usage running at around 24000kwh per year currently. It used to be higher, but I have tweaked how I use it. We have also had warm winters for the last few years.

So if you boiler is only 20 years old, something does sound very wrong.

As others have said

Wow, that sounds excessive to me.

I have a 3 bedroom detached, 10 year old Glow Worm combi boiler, double glazed, loft and cavity wall insulation, and I'm running at around 11724Kwh per year and that's above average for my area according to E.on.

CashStrapped

beardiedog wrote: »

Wow, that sounds excessive to me.

I have a 3 bedroom detached, 10 year old Glow Worm combi boiler, double glazed, loft and cavity wall insulation, and I'm running at around 11724Kwh per year and that's above average for my area according to E.on.

I think you missed the point of my post entirely. Did you even read it properly?

Of course it is high usage!! But it is not excessive for my boiler type/age and house condition. It is a 35-40 year old boiler! I have single glazed leaded windows! Poor loft insulation!

You are comparing that to your 10 year old combi boiler in a house with double glazing and what sounds like good insulation!

---

My Point?

The Op has a combi boiler that is 20 years old (should be more efficient than mine) and seemed to be using three times the amount of my very old and inefficent boiler ....therefore somthing is most certainly amiss. Possibly the AGA as we established. If you think 24000kwh is excessive what do you think of the OP's 72000kwh?!

It is very hard to compare like for like in energy costs. It all depends on the house, number of occupants, the temperature that people like to be at, the controls, how they are used, the boiler age, the boiler type.

However it is very unlikley that a 20 year old boiler will use three times the amount of gas (for a similar sized property) than a boiler twice it's age!!

That is the point I was making!