Recommended settings for efficient heating and hot water with a heat pump? How to reduce energy use.

Hi @Bev I think we're all still learning. You'll see from the COP thread that we're all currently trying to reduce the number of times the pump turns on and off to increase efficiency, though getting this right may be a bit of trial and error.

Immersion should generally only be being used when it's absolutely needed to raise the temperature more than the ASHP is able to. When you say it's on, is that just the fused switch on the control panel that's on (which is ok) or do you think it's actually operating? Do you have a separate energy read out for the immersion on the consumer unit? My immersion has used 20kWh since May.

If you have cheap overnight electricity I'd set the tank to heat up during this time and then only set it to top up the tank temperature during the day if it falls below a certain temperature. Heating it in one go could be more efficient.

Hi Neal
Thanks for this. Yes it’s the fused switch on the control panel which is switched on - from your post, I’m guessing it’s not what it looks like :)  Where are you finding the energy read out for the immersion unit please, is it easy to explain?

Yes we’ve set the tank to heat up at night, starting tonight. We took meter readings yesterday, we’re going to start taking them regularly to see what difference these tweaks make. Also we’re finding out about a Smart meter - we have solar with a feed in tariff (had them 8 years) so we’ll lose part of the tariff we think, but it’s better than being clueless about where our energy is going… I’ve looked at energy monitors but they look like a potential can of worms.

Thanks again

Bev

Here's my set up. All switches on!

The illuminated digital display shows the separate use by the immersion and back-up heater.

Here's my set up. All switches on!

The illuminated digital display shows the separate use by the immersion and back-up heater.

 

Thank you! I’m guessing all our layouts are a bit different, ours is. I will take a pic to compare.

Hi @Bev 

That COP value isn’t great. I’ve just got back to my installer because I’m not happy. It’s a factor of how efficiently the pump converts the electricity to heat, it should be above 3 on our new systems. It’s really down to the installers to get this sorted, a few of us are tweaking setting on the heat curve but unless you are comfortable doing this it should be left to the installer.

Regarding the smart meter, it won’t affect your FIT payment. My system is the same age as yours, I have a smart meter but my FIT stays the same, they still assume you export 50% even though it’s measured. It’s part of the FIT contract that is remains as agreed for the 25 years. Those who had panels installed after the FIT scheme ended would be using the export functionality of the smart meter. If you currently have the very old style meter with a wheel (you aren’t supposed too, I should have been upgraded when the panels were fitted, but maybe keep 🤫 about it), then the downside to moving to a smart meter is it won’t go backwards when you are exporting to the grid.

@hydrosam thank you. How did your installer react? Wondering if I say ‘the COP value for this system should be above 3 and it’s below 2.2’ will my installer know what I’m talking about and are they obliged to do anything about it given that they’ve done the installation. I am not aware of any minimum standards for the performance of the set-up? Sorry for all the questions...

And thanks very much for clarifying the FIT payment. We noticed a Smart Meter seems to affect some people’s tariff and not others, and we didn’t know why. Our electricity meter is only about 4 years old, we asked for an economy 7 meter when we got an electric car because it meant we could charge cheaply at night. Bulb fitted it but, according to Octopus (when we were contemplating switching), they have it on the database as a standard tariff meter when it definitely isn’t. A can of worms I’m reluctant to open. As everybody seems to be saying ‘don’t switch’ at the moment I’ve put it on the back burner. Economy 7 and Smart Meters don’t seem to go together (or Bulb say they don’t) so we’re going around in circles a bit. Contemplating a battery pack/vehicle to home but would much prefer the system is working as it should rather than chucking more tech/money at it.

My new installer, Reina group, replied very quickly and are coming out to investigate soon. They will know what you are talking about, COP is a fundamental term when it comes to heat pump operation and we have meters fitted as part of the trial so that it can be measured accurately. I don’t know whether OVO, @Jess_OVO, are monitoring the COP variance of the different systems, if they were they’d pick up systems like ours and highlight them for investigation and save us from extortionate winter bills. I’m being a bit unfair though, as I know a number of systems are being revisited after the Northern Gas catastrophe and remedial work is being carried out.

My wording to the installer was along the lines of:

The performance of my pump is fairly poor. COP of 1.9 since installed, 2.45 for the last month. I know you are busy with remedial work but I’d really appreciate you trying to figure out why my system isn’t work as well as it could. Other trialists of the OVO forum are reporting COP values well in excess of 3.0, please can you investigate. 

My original installer, Northern Gas, didn’t care. Reina group do care which provides some reassurance. 

Hi @Bev . I also have an Ecodan system. If you are happy to, can you post a photo of your meters like @nealmurphy did above? For me there are three numbers: Electricity used to power the heat pump, electricity used for the immersion, and hot water energy created. If you can share those three numbers in your screen shot we can check your COP, and see how it varies for hot water and heating.

Over the last month when the heating comes on, are the radiators hot, medium or luke warm? It will vary, but because it isn’t too cold outside yet, they shouldn’t be too hot (except maybe first thing in the morning).

Do you have a Nest thermostat connected and what temp do you have that set to?

This is mine. Important to have that white box on the left as well

This is mine. Important to have that white box on the left as well

Thank you @James_N, we are going up to take a look later so I’ll take some photographs of the set up. It’s a bit of a pain because everything is in the loft, up and down to the loft to change settings is not ideal. We didn’t realise all the controls would be up there with nothing to control them with in our living space apart from the Nest thermostat (which is what we have). I rang Ovo last week about this, we can’t access their readings either, so if we want a controller we can use in our home, we’ll have to have it fitted retrospectively.

We have the daytime heating set at 19-20, we have the water in the tank set to 45.

Had a visit from the installer last week, this particular man doesn’t think you should have your water heating on timed at all, you should leave it going all the time so the pump never has much work to do to get it back up to temperature. So we agreed he could clear all the timed settings. Another person from the same company generally goes with ‘timed’, which is what the Mitsubishi videos (which we have just discovered) also recommend. Having got up on a rather cooler morning this morning, showered and then twigged that the heating goes off when the water is being heated (meaning the house is cold in the morning when you want it to be warm), we’re learning fast and will be turning off the water heating until lunchtime when the sun is at its strongest as we have solar, not that we’ll get much in the winter but it’s not a bad principle to go by. Our man also said that ideally we’d have had a iBoost or similar fitted - it was discussed at the outset but dismissed by the installer as our plan is to get a battery pack. Should we have had an iBoost fitted - who knows? All I know is that it’s going to be more expensive to get it done retrospectively too, than it would have been if it had been done as part of the installation. Just like a control panel of some kind in our living space. Totally get that everybody’s set up is different and these, of course, are retrofits in old houses (or it is in our case) but I am bewildered at how vague this all seems to be in terms of making the most of the set up you have. It feels like it’s all been fitted and we’re now realising what we should have asked for, because we didn’t know what we needed until we had a heat pump. We assumed the monitoring was to get the most efficient set-up we could get. If I’m honest, based on where we are now we’re a bit bewildered by this whole thing. Don’t get me wrong, we’re delighted to have it! Love the heat pump. Just don’t understand how Ovo are going to get anything meaningful from our trial readings when we keep having to fiddle to work out how to optimise the installation, which we may never achieve as we have no idea what we’re doing.

Anyway, will get some shots later, thank you :)