CurtainCall
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Would anyone have a rough idea how much it cost to install a back boiler to an open fire? There is gas heating so the radiators are here.
We installed a wood burning stove with a back boiler (in a typical three bed semi) last year to reduce our gas costs and I definitely recommend it. I calculate it's saving us €1,020 in gas per year. We went for a relatively high end stove which worked out a little more expensive - it came in at €4000 all in (wood stove with back boiler, new bigger and better insulated hot water tank and all the plumbing to hook it up and the installation of all of the above). You might be interested in the maths I had worked out for it:
We have an efficient condensing gas boiler at the moment, but never the less, every hour it runs, it consumes 2.3m^3 of gas (25.3 kWh of gas per hour, and it costs €0.06 per kWh right now). That means the boiler costs €1.52 per hour to run. The carbon tax is levied on top of this: gas produced 0.23 kgCO2/kWh, which adds about €.10 per hour, so all up, the gas boiler costs €1.62 per hour. One thing to note is that gas is at a record low in price and is predicted to increase considerably as the US shale boom calms down. The carbon tax is likely to increase over time also. The price of wood will likely stay relatively flat, particularly if you have some land to grow it yourself.
Before we installed the wood burning stove, we ran the boiler for about 3 hours per day outside of the warmer months, so that's 3* 7 = 21 hours per week about 8 months of the year. Per week, that was 21* 2.3 = 48.3 m^3 of gas, which is 21*25.3 = 531.3 kWh of gas, which is 531.3kWh * €0.06 = €31.88 per week. For 8 months a year, that's €31.88 per week * 32 weeks = €1,020.16 per year to heat the house with gas.
The wood burning stove has done away with about 98% of this gas heating - we only ever turn it on for ~20 minute periods in the middle of the night if we want heat right away.
In summary, the stove saves €1,020 per year in gas costs, and so at a cost of €4000 will pay for itself in just under four years, and with a lifetime of about 15 years, will save 11 * €1,020 = €11,220 in total, which is a pretty good return on investment.
The icing on the cake is that it completes the sitting room - we love sitting by the fire. I'd guess we watch about 50% less TV because the fire provides a focal point of the room that isn't the TV. So we've definitely had a great experience so far with the wood stove + back boiler setup.
Conor.