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• FIRST POST
• Stan79
• By Stan79 28th Nov 17, 7:01 PM
• 15Posts
• 0Thanks
Stan79
Hi all,

Does anyone have any experience working out the running cost of an Air Source Heat Pump?

I've been very bad at recording readings from it so only have a few readings plus the start date to calculate from... in principle though, is this equation right?

kW used / (Days elapsed x 24hours) x tariff price per kW = cost per day

So, last winter would be:
2682kW / (87 days x 24 hours) x £0.21 = £0.27 per day

And, this summer would be:
719kW / (192 days x 24 hours) x £0.21 = £0.03 per day

Does that look right? Many thanks in advance for any help!
Page 2
• SusanF11
• By SusanF11 20th Feb 19, 5:03 PM
• 4 Posts
• 0 Thanks
SusanF11
Just wondering if you have found a solution to your heating issues?

We too are experiencing very high running costs.
• matelodave
• 20th Feb 19, 6:01 PM
• 4,923 Posts
• 3,221 Thanks
matelodave
Just wondering if you have found a solution to your heating issues?

We too are experiencing very high running costs.
Originally posted by SusanF11
My 11kw system is using around 1000kwh a month at this time of the year (the worst year was 2013 when it went up to 1600khw in January) however averaged over the whole year my total electricity consumption is jusy 7000kwh.

So dont extrapolate 1000kwh/month for every month of the year.

As said above,learn how the system works, check your controls, understand how to set them properly and make sure that the unit isn't using the boost/back-up heater to produce high hot water or high flow temperatures. Dont try using it as a normal boiler.
Never under estimate the power of stupid people in large numbers
• SusanF11
• By SusanF11 20th Feb 19, 7:26 PM
• 4 Posts
• 0 Thanks
SusanF11
My 11kw system is using around 1000kwh a month at this time of the year (the worst year was 2013 when it went up to 1600khw in January) however averaged over the whole year my total electricity consumption is jusy 7000kwh.

So dont extrapolate 1000kwh/month for every month of the year.

As said above,learn how the system works, check your controls, understand how to set them properly and make sure that the unit isn't using the boost/back-up heater to produce high hot water or high flow temperatures. Dont try using it as a normal boiler.
Originally posted by matelodave

Since moving into the house on the 7th December we have used 2354kwh. Our system heats the whole house (150m2) via polypipe underfloor heating and the hot water. Today, with an outside temperature of 8°c, our house has struggled to reach our "comfort settings". After 13 hours searching, three rooms are still searching. Our comfort setting is from 6am until 11pm with a room temperature of 18 / 18.5°c. Our setback temperature is 17.5°c.

When the house does get all the rooms up to temperature and no hot water is required, the system will continue to switch on and off (between play and pause on the heating). The circulation pumps will continually run and the heat pump outside will switch on/off. The system switches off for about 1.5 minutes then runs for 12 minutes before switching off for 1.5 minutes, then repeats the 12 minutes cycle - is this normal? Does your system do this when your heating or hot water are not demanding it? On a good day when the sun is out or we have lit the fire and the house has heated up and the system isn't searching for heat anymore, this constant on/off cycle can cost us (on a good day £4).

When we had a really cold spell a couple of weeks ago (-6° during day), we were spending £12 a day on heating, rooms didn't achieve 1°c they required to achieve to stop searching in 17 hour that they were on the "comfort" setting.
• lovesgshp
• 20th Feb 19, 7:42 PM
• 1,364 Posts
• 750 Thanks
lovesgshp
Can you set the circulating pump to only start with the compressor on?
As Manuel says in Fawlty Towers: " I Know Nothing"
• CATALOGUEKID
• 6th Aug 19, 11:50 AM
• 1 Posts
• 0 Thanks
CATALOGUEKID
HI,
We just installed an ASHP which replaced an old combi boiler.
It is used for domestic hot water and heating.
We have the old radiators which are used.

Our last bill for the month came to around £700.

I have now started to monitor the electricty usage of the ASHP as it has an electrcal meter fitted. It is using around 100KwH a day.....

This is around £470 per month just to run the ASHP for elecricity usage....

Can someone help? IS this normal?

Its a 4 bed detached house, temperature is set at 22 but never gets above 19.5 at the moment

BUt my biggest worry is the huge electricity bill per month £500 is almost another mortgage....

I checked online and most are saying that the average running cost should be around £1100 per year.....but we are looking at almost £6k running costs

Any help or direction most appreciated?
Maybe the intsaller has not set this up right

many thanks
sam
Originally posted by sam108
Hi Sam,

I have the exact same problem with my ASHP......did you manage to find a solution?

for 2018 I averaged 1,445 kwh per month...January being the most with 2490kwh and July being the least with 409kwh

as you said, it's like another mortgage payment...the only reason i can afford it at the moment is because of the RHI payment i receive

Any help or advice will be greatly appreciated

regards

Tom
• keithhubner
• 5th Dec 19, 11:11 PM
• 1 Posts
• 0 Thanks
keithhubner
Hi,
I've also had a crazy bill looking at about £3K / year. I've bought a monitor to see what might be causing this. I have a feeling it might be linked to the immersion heater coming on too ofter, but trying to get to the bottom of it.

Would be interested to hear other people's experiences.

I'm monitoring the consumption and will see how this pans out.
• mrmmhf
• By mrmmhf 6th Dec 19, 4:39 PM
• 74 Posts
• 87 Thanks
mrmmhf
Our air source heat pump has now been operational since the spring.

To see how it performed over the autumn, including a very cold November, please check out this video.

I address our running costs, and the numbers were hugely favourable.

https://youtu.be/Z6Ce4bsxt9g

Additional information and data available here: https://myhomefarm.co.uk/caernarfon-18kw-autumn-air-source-heat-pump-review
• mrmmhf
• By mrmmhf 6th Dec 19, 4:42 PM
• 74 Posts
• 87 Thanks
mrmmhf
Hi all,

Does anyone have any experience working out the running cost of an Air Source Heat Pump?

I've been very bad at recording readings from it so only have a few readings plus the start date to calculate from... in principle though, is this equation right?

kW used / (Days elapsed x 24hours) x tariff price per kW = cost per day

So, last winter would be:
2682kW / (87 days x 24 hours) x £0.21 = £0.27 per day

And, this summer would be:
719kW / (192 days x 24 hours) x £0.21 = £0.03 per day

Does that look right? Many thanks in advance for any help!
Originally posted by Stan79
Those numbers look ok. Not too scary. Our tariff is much lower than yours. Who’s your provider?
• matelodave
• 6th Dec 19, 7:30 PM
• 4,923 Posts
• 3,221 Thanks
matelodave
your calculation works out cost per hour not per day - you dont need the 24 hour bit.

I'm astonished at your cost per kwh, mine is only 12p, so if I were you I put some effort into getting yourself on a much better tariff.
Never under estimate the power of stupid people in large numbers