How much would a new boiler save me per year? On band G/65% atm.

Hockeynut

I logged on tonight to look at energy prices, as our fixed deal is due to expire. So I got to thinking I wonder whether it would actually be pretty quick to pay back itself if we were to get a new one, given modern efficiencies seem to be around 90%+.

Anyway, I know the boiler has been in since way before we moved in a couple of years ago, and it's probably the original, so 16 ish years old. It's an Ideal Classic RS40, which I believe is band G & approx 65% efficient.

We live in a 3 bed house, which is about 16 years old, with approx 12 small radiators, no TRV's. We pay approx ~£960/year gas & ~£480 electricity, which feels like a lot for a house which isn't that old (but I might be wrong on that). We only use the gas for heating/hot water, and once in a blue moon the gas fire.


Any help appreciated.

Hockeynut

Just realised I should've probably posting this in the forum one level higher than this. Sorry. If anyone can move it.

Cardew

There are scores of posts on the financial viability of getting a new boiler to replace a less efficient boiler.


The overwhelming consensus of advice is never to replace a working boiler. many of us have 25-30 year old boilers that are still going strong.


The 90% efficiency of modern condensing boilers is rarely achieved in practice; they would to be kept in 'condensing mode' all the time.


£960 pa with gas 4p/kWh is 24,000kWh pa which is certainly well above average.(Average was 16,500kWh and is now apparently 13,500kWh)


However even in the unlikely event that you gained an increase in your efficiency from 65% to 90% you would save approx £260 a year.


A new boiler is likely to cost at least £2,000 and possibly quite a bit more. So a long time to pay back.


You would do far better to spend any money on insulation and fitting TRVs.


TRVs are mandatory on new CH houses, not sure if that applies on a boiler exchange.

Hockeynut

Cardew wrote: »

There are scores of posts on the financial viability of getting a new boiler to replace a less efficient boiler.

The overwhelming consensus of advice is never to replace a working boiler. many of us have 25-30 year old boilers that are still going strong.

The 90% efficiency of modern condensing boilers is rarely achieved in practice; they would to be kept in 'condensing mode' all the time.

Ah. Sorry about that, I appreciate you not just saying use the search and continuing to reply further.

Cardew wrote: »

£960 pa with gas 4p/kWh is 24,000kWh pa which is certainly well above average.(Average was 16,500kWh and is now apparently 13,500kWh)

You would do far better to spend any money on insulation and fitting TRVs.

TRVs are mandatory on new CH houses, not sure if that applies on a boiler exchange.

That is far more concerning, that we are using so much more that average. Given that I never really have the thermostat above 20, in fact it usually sits between 18-19. Which I thought was fairly tight, however I've always felt our bill was quite high. The heating is also on timer, so that it isn't on when we don't need it to be. However, despite looking at it before, I suspect I've never got the hot water timing quite right, having had a combi in our old house I never needed to! Still, I can't believe how high over the average we are. I can't even see TRV saving that much and bridging the gap. The roof is already insulated.

matelodave

How much insulation have you got in the roof, it should be at least 200mm, preferably 300mm. Likewise the cost of cavity wall insulation would give you a quicker return than changing the boiler.


Try setting your hot water temperature a bit lower and only heat your hot water tank when you need it. Make sure it's well insulated, even a foam insulated one would benefit from an extra jacket. Try using less hot water as well by taking shorter showers or having shallower baths, don't let it run down the sink whilst washing or rinsing.


A programmable room thermostat would allow you a bit more control over your heating times & temperatures. Make sure it's located where it isn't in a draught, on a cold wall and is actually controlling the system.
It needs to be located where there's a radiator that heats the room as well. A thermostat that doesn't turn off because it's in the wrong place or where the radiator can't warm the room enough won't control the heating system properly.

Cardew

Hockeynut wrote: »

I can't even see TRV saving that much

Without a TRV a radiator is either On or Off.


Take your bedroom radiators. Do you switch them off completely during the day? A TRV enable you to easily turn them down/off and back to the required temperature before you go to bed.

Hockeynut

matelodave wrote: »

How much insulation have you got in the roof, it should be at least 200mm, preferably 300mm. Likewise the cost of cavity wall insulation would give you a quicker return than changing the boiler.

I'll have to check that out. Never measured, it was in when we moved in.

matelodave wrote: »

Try setting your hot water temperature a bit lower and only heat your hot water tank when you need it. Make sure it's well insulated, even a foam insulated one would benefit from an extra jacket. Try using less hot water as well by taking shorter showers or having shallower baths, don't let it run down the sink whilst washing or rinsing.

We hardly use the bath, mostly using our electric shower, which again shows how crazy it is that we are using so much gas. Something is amiss.

matelodave wrote: »

A programmable room thermostat would allow you a bit more control over your heating times & temperatures.

I assume you mean one like we had at our old house with our new boiler. Where you can set different temperatures at different times of the day?

Cardew wrote: »

Without a TRV a radiator is either On or Off.

Take your bedroom radiators. Do you switch them off completely during the day? A TRV enable you to easily turn them down/off and back to the required temperature before you go to bed.

But the main heating control specifies it only comes on at certain times, so it wouldn't be on overnight anyway?

I always thought that a TRV was to give a bit more temperature control per room. But not typically always adjusting them.

I wish you could get the equivalent of the British Gas gadget which shows how much power we are consuming!

matelodave

Try reading the meter on a daily or weekly basis (put it into a spreadsheet) then monitor your own consumption - you don't need a special gadget. You can then tweak your controls a bit and refer to your own readings to check what effect they have.


Non of it is rocket science and you don't need any special stuff, just a bit of effort and you can save a fair bit. If you don't measure it yourself you can't know how much you are using or what happens when you make adjustments. Likewise you won't know what your bills will be until they drop through the door.

Cardew

Hockeynut wrote: »

I'll have to check that out. Never measured, it was in when we moved in.

We hardly use the bath, mostly using our electric shower, which again shows how crazy it is that we are using so much gas. Something is amiss.

I assume you mean one like we had at our old house with our new boiler. Where you can set different temperatures at different times of the day?

But the main heating control specifies it only comes on at certain times, so it wouldn't be on overnight anyway?

I always thought that a TRV was to give a bit more temperature control per room. But not typically always adjusting them.

I wish you could get the equivalent of the British Gas gadget which shows how much power we are consuming!

The point of a TRV in bedrooms is that you switch them off or turn them down during the day when the bedrooms don't need heating, and turn them up an hour or so before you go to bed.


A 'gadget' to show instantaneous gas consumption/cost would be of little use. It might show as high as £1.50 an hour when the boiler is running - but of course even when you have CH and HW demanded, the boiler will be switching on and off, or on more modern boilers modulating(varying output)


Your gas meter is the best device to monitor consumption.