What's your monthly SCOP

NedS

There is some debate around whether a legionella cycle is required with a closed pressurised system. The legionella bacteria would have to enter the system in the first place, and this most commonly occurs through vented header tanks in the loft space. I'm not running a regular legionella cycle and only heat our DHW tank to 45C. If we have negative electricity on Agile, then I give the DHW tank a blast, but otherwise don't worry about it. My DHW COP in summer is typically 3 to 3.5 (mine is lower than it could be as I also have to heat a 50L buffer tank in the primary return).

akwexavante

I agree, if i could change it to once a month or off altogether i would but I'm told i can't on this system. I can change the day of the week and time only.

NedS

akwexavante said:

I agree, if i could change it to once a month or off altogether i would but I'm told i can't on this system. I can change the day of the week and time only.

Annoying. I'd keep changing the day or time back and forth so it never triggers. At least I can turn mine off.

QrizB

This thread has been quiet for a bit, but I thought I'd bump it to share the link to the new "Octopus Cosy Heat Pump Dashboard:

https://octopus.energy/cosy-heat-pump-performance/

Here are the current statistics:

And the blog about the dashboard's development:

https://octopus.energy/blog/making-of-cosy-dashboard

zxzxzx

Cosy 6 installed end of April so first full month. Bill £36, credit for solar £33 actual cost for month £3.13 using Cosy tariff and batteries, sunny spell at the end of the month meant hot water only.

Cop just above average compared to above. Not unhappy to have had calor combi removed!

Newbie_John

Daikin A2A, Nov 2025- April 2026

4471kWh of heat, 1013kWh of electricity - 4.41 SCOP.

It would be higher if my preset temperature was constant through the day but it follows Cosy rates and jumps at 4am from 19°C to 22°C which has its negative impact on SCOP but positive on £ costs.

Saying that, I've learnt now how to use "Econo" feature that prevents compressor from working too hard during temperature jumps, so should improve little bit next year - especially when I don't need 22°C at 5am, as long as it gets there for 7am then I'll be alright.

April COP: 4.90 (only 58kWh used)

March: 4.67

February: 4.45

January: 3.91

December: 4.63 (quite warm)

November: 4.54 (first month, a lot of testing)

Numbers obtained using Daikin Onectapp data (estimation).

FreeBear

Saying that, I've learnt now how to use "Econo" feature that prevents compressor from working too hard during temperature jumps, so should improve little bit next year - especially when I don't need 22°C at 5am, as long as it gets there for 7am then I'll be alright.

One strategy that I've been using this year is to increase the target temperature by 0.5°C every half hour from 06:00 to 08:30. This often means the heating doesn't fire up until it really needs to in order to be at temperature when I get up at 09:00. But this would only work for you if you have fine grain control over temperature/time throughout the day.

Magnitio

Only had our heat pump for a couple of weeks, but impressed so far. Heating overnight to 48 degrees using less than 0.7kWh per day with an average COP of 5.13.

TroubledTarts

As we only set our hot water to 40oC in the summer it's an estimated 5.4 for us. No heating.

Though really the yearly average should remove these summer months imo as the outliers.

NedS

https://forums.moneysavingexpert.com/discussion/comment/82066889#Comment_82066889

That's impressive.

We've been away for a couple weeks, and reheated the tank from cold (24C) today, using 0.9kWh to heat to 42C. The COP was 5.0 and the temperature was 31C outside at the time.

We reduce the target temperature summer as we don't need 48C for showering.