Old boiler consumes unbelievable amount of gas

ianna_2

dear all, I'd appreciate any help, any advice, as I'm not sure what to do.

We have an old boiler, Vaillant, which is about 20 years old. It works properly, but... every year its about 64000 kwh of gas. A year ago we cleaned radiators and the consumption rose up to 72000, then this year went down to 64301, but it's much anyway, right? We live in a 3 bedroom house (built around 1930), also have an AGA responsible for heating up water - maybe that's add to the consumption? But what should we do to lower it? Thank you!

victor2

That sounds very high, but a lot could depend on how you use it. Is the heating always on and are the radiators very hot? What controls do you have - main thermostat and thermostatic radiator valves on each radiator?
Do you get the boiler serviced annually? If the next service will not be due in the near future, maybe get it done early and specifically ask the engineer to check it.
You could try turning the boiler down to a low temperature and run the heating as you normally would but check the gas meter at the same time each day for a while to get an idea how much gas the boiler is using. Is the Aga gas fired as well? If it is, you won't know which appliance is responsible for the high consumption unless you use one without the other while checking meter readings.

reeac

ianna wrote: »

dear all, I'd appreciate any help, any advice, as I'm not sure what to do.

We have an old boiler, Vaillant, which is about 20 years old. It works properly, but... every year its about 64000 kwh of gas. A year ago we cleaned radiators and the consumption rose up to 72000, then this year went down to 64301, but it's much anyway, right? We live in a 3 bedroom house (built around 1930), also have an AGA responsible for heating up water - maybe that's add to the consumption? But what should we do to lower it? Thank you!

I assume that the service man can measure the boiler efficiency in the same way as is done every time for my oil boiler. Requires measurement of the temperature of the exhaust. That efficiency would be the starting point. Our boiler is 18 years old but is still showing around 85 net efficiency and nearly 90 gross so age needn't be a killer.

matelodave

As said - you really need to know which appliance (boiler or AGA) is consuming the gas. Does the boiler heat the water or is that only the AGA. AGA's are not actually renowned for their economy and you could easily find that it's making a very significant contribution to your bills. How does it heat the water - is it thermostatically controlled. How is the water circulated - pump or gravity

Look at your heating controls, have you got a programmer, room thermostat, TRV's etc. how are they set up. What about insulation - cavity wall, loft, double glazing or even draught proofing. Make sure that you hot water tank and associated pipework is properly insulated. There's probably a lot you can do to improve it all.

Likewise have an appraisal of when you are heating and using both the heating and hot water.

Reducing your consumption of hot water by taking shorter showers, shallower baths and fewer of them. Fit flow restrictors to your taps and shower.

Don't let hot water run down the sink when washing stuff (including you). Rinse stuff (including your hands etc) in cold water. Every time you draw off water to get it hot at the taps you waste the same amount which sits in the pipework, getting cold.

Finally check your consumption by reading the meters regularly - ideally weekly but at least once a month to see when it's all being used - you might be surprised

Cardew

I find it hard to believe a 3 bed house could use 72,000kWh pa.


It would be worth checking if your gas meter is Imperial(cubic feet) or Metric(cubic metres)


Loads of people have reported on MSE that they have a metric meter but are charged for and Imperial meter - hence they are charged for 2.83 times more gas than they have consumed.

chanz4

-Oven Gas
Technical SpecificationsDimensions (mm) 987 (w) x 679 (d) x 851 (h)Weight 406 kgModel availability/designation NaturalGasWithout water heating GCGCWith water heating GCBGCBApprox. weekly fuel consumption Without water heating 425 kWh60 litresWith water heating 601 kWh84 litresOutput to domestic hot water (kW per 24 hours) 26.426.4

C_Mababejive

I wonder what model of boiler it is? Is it a sine 18?

matelodave

chanz4 wrote: »

-Oven Gas
Technical SpecificationsDimensions (mm) 987 (w) x 679 (d) x 851 (h)Weight 406 kgModel availability/designation NaturalGasWithout water heating GCGCWith water heating GCBGCBApprox. weekly fuel consumption Without water heating 425 kWh60 litresWith water heating 601 kWh84 litresOutput to domestic hot water (kW per 24 hours) 26.426.4

How do you know what sort of AGA it is. Likewise a lot depends on how it's used and how it's been configured. It might also be 20 years old as well.
Lots more information is required. Like how many people in the household. do they all go out during the day or is the heating and hot water on all day flogging it's heart out.
How many bathrooms, how many showers or baths a day and for how long.

AndyPK

I think you will find the AGA is the source of the consumption !

Do you run it summer and winter ? I would suggest you only use in winter!

Either way, turn the AGA off for one month in summer and measure the consumption difference. compared to another month in summer.

I doubt the boiler is inefficient. You would be better of getting the hotwater running off boiler or immersion so you can shut the AGA off as much as possible.


p.s the variance between different years is probably down to weather conditions and not to do with cleaning.

p.p.s Make sure you are on a good gas tariff! Npower Jan 2017 online price fix would be worth looking at.

ianna_2

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.

ianna_2

Andy, i'd love to switch AGA off, but I cook on it. )) But probably we'll have to check it as you suggested, would be interesting! We usually have around 20000 kwh in periods June to Dec, and around 40000 Dec to June.