Is this realistic, use 35% less gas?

r2015

I currently use about 17,000 kWh of gas a year with my old inefficient warm air heating and HWC for hot water.


Is it realistic for me to use 35% less gas a year when I replace my old inefficient heating with a modern combi boiler?

Robwiz

You'd need to give more information for anyone to respond meaningfully. How big is your home, what's it construction type and level of insulation, what's your heating need (hours and temperature) and hot water usage?

Generally people use about 15% less gas with warm air, but a new condensing boiler would be maybe 10% more efficient.

matelodave

Any system is only as good as the controls and the way that you use it. One would hope that a new heating system would be better controlled but you might find that you are now heating more spaces, especially if you've now got radiators in each room and now keep them cosier than before.

Many warm air systems just blew air around, mainly into the hall and hoped it would get into the rest of the house, others were just big convectors with vents above the rooms so it depends on what you had before and how you used it.
We've had both types and neither were all that effective in heating the whole house properly.

About 15 years ago we changed from a totally knackered system boiler (with hot water tank) with a pilot light to a modern electronically controlled combi, upgraded the controls to thermostatic rad valves and installed a programmable thermostat. The improvement in heating performance was immediately apparent as was the abundant supply of hot water.

Our bills went down by about 30% but I don't know which changes had the most benefit, new boiler or new controls.

It was before swapping energy suppliers was the norm and I didn't really keep an eye on my meter like I do now. It's a lot easier to check & compare your consumption by energy used rather than guess how much you've saved moneywise.

SailorSam

One of the things you need to consider, especially if your old system is working with no problems is, is it worth spending perhaps thousands on a new system just to save a couple of hundred quid off your bills. Remember also that older boilers use to go on and on with little maintenance and modern boilers could be obselete in less than 5yrs and need renewing again.

r2015

One of the things you need to consider, especially if your old system is working with no problems is, is it worth spending perhaps thousands on a new system just to save a couple of hundred quid off your bills.

I'm not getting new heating to save a few bob on the bills but that will be helpful.

I'm getting new heating so I can sell my house and want an idea as to what to tell prospective buyers their bills will be.

SailorSam

Then you need to consider, is the amount you're thinking on spending going to add that to the price you get for the house.

r2015

Then you need to consider, is the amount you're thinking on spending going to add that to the price you get for the house.

Considering that I never got any offers because no one wanted warm air heating I think it will.

matelodave

We had my Mum's place on the market for the best part of six months - electric heating. Spent £3k on gas central heating and it sold within three weeks for the price we were asking.

r2015

We had my Mum's place on the market for the best part of six months - electric heating

Mine was on the market for over a year then I gave up as the solicitor wanted more money for another home report and other stuff.

forgotmyname

I loved our warm air heating when we had a flat many years ago. It was brilliant always warm and the bills were low.

Well insulated though.

r2015

I loved our warm air heating

So did I until it prevented my house being sold.