Air source heat pump

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I have not got a like for like comparison as its only 6 months since installation. My average monthly bill before was £180 (old system, electric boiler). With the new ASHP system the average monthly bill is £110, so far, and this average monthly cost is still coming down as I submit meter readings. I expecting it to settle somewhere just under £100 per month when it has gone through a full year. Another point to make is that I kept tweaking thermostats in different parts of the house to economise with the old system, keeping less used rooms cooler. I don't have to think about costs so much with the ashp as it is still much cheaper to run and I can keep all areas comfortably warm, so again not like for like... which is why I said approximately halved.

Nov 2017 average daily - old system - 49 units

Dec 2017 average daily - ashp system - 24 units

[Nigel Bridgman-Elliot]

> (old system, electric boiler)

Was that using off peak electricity ?

Water fed radiators ?

> Nov 2017 average daily - old system - 49 units

I notice our storage heaters used around 30 units. (Was 40 units before extra insulation efforts was put in place, estimate another 10% improvement when all of those are finished.)
 

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No, not using off-peak, all single metering standard rate... so further economies to be made with possible metering options. I'm just inclined to keep shopping around and switch to the lowest single tariff.

I have existing wet underfloor heating. The ASHP replaced the electric boiler, so this was a matter of changing the heat source that feeds the same system, as opposed to ripping out an old system and a big property wide installation of new stuff. A big decision though as cheap boiler expensive to run replaced by an expensive ASHP but much cheaper to run. So you're quite right to be asking these questions, its a big decisions, and every property is different so what you achieve in one house may not necessarily translate to the next.

The bill no longer feels expensive. With RHI's and savings from previous bills, I am happy that the system will definitely pay for itself. Most importantly its a much more comfortable house.