Air Source Heat Pump - INSANE bills!

Loubda

We moved into a newly renovated house that has an Air Source Heat Pump. We are really struggling with high bills and we aren’t sure why. Our heating has just been switched in today for the first time since the summer....it’s been on “frost” setting all summer. The hot water is on a timer.
It is a cottage and most of the time it’s on,y my daughter and I living here, the rooms that get a lot of sun tend to be warm but the other rooms are pretty cold and don’t necessarily reached desired temps as per thermostat (we have Heatmiser system).
We are with SSE.
At one point last year they estimated our annual consumption to be 13,500KW. The latest estimate is 10,500 KW but I suspect that’s because it’s off all summer so I expect it to go back up to 13,500KW. Even the guy who read the meter from SSE say it’s high.
Cost wise we are paying over £230 per bill. SSE estimate at 10,500KW our annual bill will be £1799.00 (bearing in mind I think that estimate is going to be closer to the 13.5k now we have the heating on).
Am I doing something wrong? I have had it serviced and the company who supplied and look after it aren’t much help. I understand that it’s best to keep it at a constant temperature. Now the heating is on, it’s set at 21 degrees throughout the day and 17 at night. That said, even before I switched the heating on, it was between 15 and 18 depending on what room you were in. I feel like we are just throwing money away....I don’t know who to ask to help me out with getting to the bottom of why our bills are so high, can anyone help me or direct me to someone who can. We have one room that has a window that’s not double glazed ....but the rest is pretty good I think. There are a few drafts here and there but I doubt enough to be the culprit. Please help me!!!

matelodave

There is a similar question on the gas and electricity forum and this is the same answer that I've put on there

What make and model is the ASHP and what programmers/thermostats has it got?

My Daikin ASHP wont run the central heating and hot water simultaneously so my water heating times are set to come on before I want heating.

Mines set for about 2 hours a day. I have my immersion and boost heaters switched off and I find that the heat pump gives us sufficient hot water for out daily needs. We have the hot water tank set for 45 degrees which we find works for us. The heatpump boosts it to 60degrees once a week to sterilise the tank.

Regading heating - we are at home all day so the heating is on virtually all the time with a set back by about three degrees overnight and in rooms that aren't in use. We've got programmable thermostats in each room (we have underfloor heating) which allows us to control the temperature according to their usage.

For example the lounge gets heated virtually all day but the bathroom and bed rooms only in the mornings and at bedtime. However that said we do not shut it off, only turn it down otherwise it takes hours or even days to get the house back up to temperature.

Heatpumps run with a flow temperature much lower than a conventional system so will take a lot longer to reheat the house if you let it get stone cold. Increasing the flow temperatures will significantly increase your running costs as will using the immersion and boost heaters. Our flow temperature is weather compensated and fluctuates between 30-45 degrees. Pushing it up to 50-55 degrees would increase our running cost by around 25%

You need to experiment to try and optimise your timings and temperatures to suit your lifestyle. It would be a good idea to start reading and recording your leccy meter every week at roughly the same time to see how your adjustments affect your energy consumption.

However as we are now moving into the winter period you'll find that you consumption will increase quite dramatically.

I've been monitoring my consumption for over eight years and the consumption pattern is virtually the same for every year very low in the summer and very high in the winter although that said we only use a total of 7200kwh a year but around 1200kwh of that in December alone. Summer months are about 250-300kwh/month.

We are on the cheapest single rate tariff that I can get (presently around 11.5p/kwh and 22p/day standing charge) which works out at around £76 month.As we heat all day and turn it down at night an E7 tariff wouldn't work for us.

BTW because I understand how it works I have tweaked the settings a bit from the default settings and readjusted the weather compensation settings

bruce2110

As previous post says we don’t know what type of system you have (manf’), however, some simple points to look out for are:

- DHW start and stop temps should be around 47o - max 55o this should prevent any back up boiler settings usually immersion heater based cutting in

- check alarm logs on on system, is it running normally?

- pasteurisation (legionella) is this set correctly as each manf’ may use different styles of time clock/settings?

If you can provide manf’ details I’m sure some one will have the relevant experience to advice!

HTH!

Cardew

Welcome to the forum.



Using 10,500kWh or 13,500kWh a year is not insane consumption.


I assume the '£230 a bill' is in winter; although you have just switched on your heatng??


Many people use 4,000kWh+ PA+ without heating.

Loubda

Wow - I’m surprised that you think my bills are normal. I really am. My in-laws bill is £85 and they are in a much less well insulated than ours and a much bigger house - my parents bills are again under £100 and their house is about double the size of ours. How much are your bills out of interest? I’m not questioning you - I haven’t lived in the UK for 20 years but it seems like our bill is way way more than anyone else I talk to. In fact they are shocked when I tell them how much we are paying. We are paying a standing order of £239 every month - all through the year and we have no credit so we are not overpaying.

Loubda

The electric company also told me that 13,500 kw is extremely high annually - there are 2 of us in the house and we are abroad about 4 months per year.

welshmoneylover

Your heating system is an expensive one, that’s why.

Never compare your consumption to others, it’s like comparing your grocery shopping costs!!

Cardew

Loubda wrote: »

'Insane bills'



Wow - I’m surprised that you think my bills are normal. I really am.


The electric company also told me that 13,500 kw is extremely high annually - there are 2 of us in the house and we are abroad about 4 months per year.

I didn't say your bills were normal, I said they weren't insane.



It is extremely high for electricity if you use gas/oil for heating and hot water.


This is from Ofgem's site. https://www.ofgem.gov.uk/gas/retail-market/monitoring-data-and-statistics/typical-domestic-consumption-values





Typical Domestic Consumption Values published 2017
TDCVs kWh

Gas Low 8,000

Medium 12,000

High 17,000



Electricity: Profile Class 1 Low 1,900

Medium 3,100

High 4,600 Electricity:



Profile Class 2
Low 2,500
Medium 4,200

High 7,100


What is the point of asking me for my consumption when you don't know if I live alone in a modern well insulated 1 bed flat, or a run down 8 bed mansion with 8 kids.


It is also pertinent to point out that some ASHP installations are extremely poor and thus inefficient.

matelodave

As Cardew says some systems are poorly designed, especially those that have been installed as oil or gas boiler replacements and just put onto an existing heating system.

Many are under specified or not set up correctly and a lot of heat pump owners dont learn know how to use them properly and try to run their systems as though they were conventional boilers.

High flow or water temperatures (above 50c) will significantly increase the running costs because they activate the boost or immersion heaters. It's reckoned that every degree above 35c will increase the running cost by 2.5% so the lower you can keep it the less it will cost to run.