Turn Off Heat Pump at night?

Baldlygo

Patrol said:

As a matter of interest how much did your electricity bill go up by and how much would you have spent on oil

What make / model heat pump is it, someone here might be able to advise further if they know that. Do you have a manual for it, that might provide meaningful information for you

There is probably a setting to reduce the flow, room, and hot water temperatures overnight

Not sure what you mean by Electric ballon. Could you be clearer e.g. heating this with the heat pump, immersion, or something else like back boiler or solar thermal

 Dec,Jan,Feb 2023 approx. 360 Euros (Yes we live in France!) - Dec,Jan,Feb 2024 - 960 Euros - Oil cost 1700 Euros a year

Thermor Aerolia 8

There are settings with a manual adjustment - but difficult to understand (even the installer struggled)

The hot water is separate and has an immersion heater on all the time.

Baldlygo

Spoonie_Turtle said:

Our ASHP was a retrofit (although with rads installed for the first time with it) and doesn't have a setback setting so we do turn it off at night (via the heating schedule, it's not allowed to kick in between certain times) because it was feeling like a huge waste to have it heating to the same temperature at night especially during colder nights - whirring away at -ve℃ outside to keep inside at 18℃ at 3am, for instance. 
[The circulation pump does still keep going overnight for antifreeze or defrost.]

But your heat pump is newer than ours so if it is a model with a setback option, that would be more efficient than turning the heating off altogether.

In terms of energy usage, I don't have exact data.  Our heat pump's usage has gone down since changing it to the heating off at night, but I also changed the hot water settings at the same time, so that may have made some or all of the usage difference, I really don't know.

Thanks, Spoonie_Turtle - It looks like I can try and see if I can make savings. 
On the subject of circulation pump and antifreeze are you thinking of outside the house? ie. connection to the heat pump outside. I thought the circulation pump was for radiators only and we never had a problem turning off with the oil boiler.

Netexporter

The hot water is separate and has an immersion heater on all the time.

That will be eating money.

I've only found non-English specifications but that range uses R32 refrigerant and should give a COP of about 5 at a 35 degree flow temperature at 7 degrees outside temperature.

paul991

just  had a quick look you can access controls on the coaxial exchanger and a wifi app option was available
saying that I hope you have a full copy of the instructions in English or you can speak French

Spoonie_Turtle

Baldlygo said:

Spoonie_Turtle said:

Our ASHP was a retrofit (although with rads installed for the first time with it) and doesn't have a setback setting so we do turn it off at night (via the heating schedule, it's not allowed to kick in between certain times) because it was feeling like a huge waste to have it heating to the same temperature at night especially during colder nights - whirring away at -ve℃ outside to keep inside at 18℃ at 3am, for instance. 
[The circulation pump does still keep going overnight for antifreeze or defrost.]

But your heat pump is newer than ours so if it is a model with a setback option, that would be more efficient than turning the heating off altogether.

In terms of energy usage, I don't have exact data.  Our heat pump's usage has gone down since changing it to the heating off at night, but I also changed the hot water settings at the same time, so that may have made some or all of the usage difference, I really don't know.

Thanks, Spoonie_Turtle - It looks like I can try and see if I can make savings. 
On the subject of circulation pump and antifreeze are you thinking of outside the house? ie. connection to the heat pump outside. I thought the circulation pump was for radiators only and we never had a problem turning off with the oil boiler.

Well it's a pump we hear indoors, I don't know what exactly it's doing or really why it's doing it.  It can be heard most clearly from the airing cupboard where the indoors installation is.  I've not heard it from outside.  My brain's too muddled to retrieve what the explanation was that I've read about it, but it was definitely called the circulation pump and it was triggered by lower temperatures.  I've also read about the outside unit defrosting(?) but I'm fairly sure that was something different.  Plus when the outside unit is doing things, we hear that more from downstairs in the part of two rooms nearer the unit than upstairs in the airing cupboard.

shinytop

Baldlygo said:

We have had our oil boiler replaced with a heat pump six months ago. It just heats the existing 7 radiators. I'm reasonably pleased with its performance even when the temperature drops below zero. However, our electricity usage has almost trebled in those coldest months.
The Heat Pump runs 24/24. I used to set a timer to turn off our oil boiler between 10 pm and 7.30 am and felt this made savings by not having heat generated at night. We are retired so we do need the heat in the house during the daytime every day. Another consideration is that the radiator pump also runs 24/24 and it does make a continuous sound.
My question here is would it save us some money or could it cause harm to our Heat Pump if we turned it off every night?

I've done detailed measurements comparing setbacks, switch offs and continuous.  Switching off for 6 hours saves me money, 15-20%.  But.... this only works if the flow temp is constant or on weather compensation. And if it is, the house drops 3 -4 degrees overnight and takes 3-4 hours to warm up.  We're happy with that.  Our ASHP can also be set up to vary the flow temp automatically to maintain a set room temperature. This is very effective but it bumps up the flow temp for 1-2 hours and wipes out a lot of the savings.

Using 3 times the electricity may be OK. Are you able to compare your oil energy use with the ASHP?    

Reed_Richards

@shinytop, those figures are very helpful.  I got my first programmable room thermostat in 1998 and rapidly concluded that I like it a bit warmer in the evenings, when I'm largely sitting down.  So for the last 26 years I have had my heating controls ramp up the temperature gradually during the day and then set back the temperature at night.  That still works as well for me with the heat pump as it did with the gas boiler in my old house.

koru

Have a look at this guide by Heat Geek: https://www.heatgeek.com/should-your-heating-be-left-on-all-the-time-or-not/

Despite their 'quirky' image, they are some of the most thoughtful commentary that you'll find.

MP1995

If you are on Octuous Agile and have underfloor heating I suggest this is one big storage radiator and you don't turn off at night and take advantage of cheap electricity. This is what we find at this time of year in particular.

wrf12345

a cold bedroom gives a better sleep