ASHP Cut-off Temperatures: What's Your Setting and is a Your Heating Still On?
My system has been running 24/7 on weather compensation from last September until today when I fitted a thermostat.
I did think about just changing the weather comp curve to 20@20, but then the pump would still run.
My wife still has the heating on as of this evening, she wanted it at 24 in the lounge. I tweaked the low temperature end of the curve up from 35 to 37.5 to make the rads feel warm when she turns the stat up.
Off grid on the isle of purbeck
2.4kW solar, 15kWh Seplos Mason, Outback power systems 3kW inverter/charger, solid fuel heating with air/air for shoulder months, 10 acres of heathland/woods.
My wife’s house: 1946 3 bed end of terrace in Somerset, ASHP with rads + UFH, triple glazed, retrofit IWI in troublesome rooms, small rear extension.
I imagine that for those of you with “automated” systems, your heat pumps must have kicked in this week with the chill in the air.
For the rest of us with more basic, older controls (like mine), when do you plan on switching your heat pumps on for heating? Or did you give in to the colder temperatures these past few days?
Get a copy of The Ultimate Guide to Heat Pumps
Subscribe and follow our Homeowners’ Q&A heat pump podcast
This year it been rubbish weather in Scotland, think we missed out on summer, it was too wet to get warm. Last year it was October before the heat went on, this year beginning of September - global warming doing it's thing - making Scotland colder! But it's let me fiddle with settings and PV pays for any mistakes and any higher electricity consumption.
@editor as my smart thermostat system is "on" all the time I guess you could class it as automated and yes it has kicked in in early mornings and a little at night this week.
In the wilds of Cambridgeshire we have had a couple of 3 - 5 degree nights but the temperatures this year have been frequently under par since the start of La Nina
5 Bedroom House in Cambridgeshire, double glazing, 300mm loft insulation and cavity wall insulation
Design temperature 21C @ OAT -2C = 10.2Kw heat loss
Bivalent system containing:
12Kw Samsung High Temperature Quiet (Gen 6) heat pump
26Kw Grant Blue Flame Oil Boiler
All controlled with Honeywell Home smart thermostat
If heating shuts off for the summer but is still needed to heat hot water is that economical or expensive due to heating from cold?
@suzy-shadow Hi, Domestic hot water production is generally less efficient in itself. For example my combined heating and hot water efficiency is on average 4.3 COP. Hot water only production over the summer has been a COP of 3.6.
Is it more or less expensive? That is a difficult question to answer as it depends on tariff prices, hot water tank efficencies etc. In my case I find it cheaper to heat my 200 litre tank to 55 Celsius and take a hit on my COP value which all happens during a cheap electricity period in the night. This tank full in most cases lasts all day and costs on average 17p per day. If I made the COP value better by reducing the tank temperature then the hot water would possibly need 2 heating cycles in a day, 1 in the morning and another in the afternoon due to hot water running low, costing approximately 40p to 50p a day if that makes sense
Hopefully that helps answer your question
5 Bedroom House in Cambridgeshire, double glazing, 300mm loft insulation and cavity wall insulation
Design temperature 21C @ OAT -2C = 10.2Kw heat loss
Bivalent system containing:
12Kw Samsung High Temperature Quiet (Gen 6) heat pump
26Kw Grant Blue Flame Oil Boiler
All controlled with Honeywell Home smart thermostat
- 26 Forums
- 2,255 Topics
- 50.3 K Posts
- 709 Online
- 5,918 Members
Join Us!
Podcast Picks
Latest Posts
-
RE: Daikin Altherma 3 / HomeAssistant
@ubert767, it’s a little unclear from your post, so for...
By Majordennisbloodnok , 6 minutes ago
-
RE: My experience with 3 heat pump surveys: Heat Geek, British Gas & Octopus
I wanted to provide an update in regards to the insulat...
By DREI , 29 minutes ago
-
RE: Help me keep the faith with my air source heat pump installation
@jamespa i cant seem to find the same sensors/readings ...
By AdamK , 31 minutes ago
-
RE: Radiator Sizing Dilemma: Vertical vs Type 33 for Low-Temperature Heat Pump Systems
That's my main concern too. On top of that, I ...
By DREI , 56 minutes ago
-
RE: Are We Sleepwalking Into Another Race to the Bottom?
Also it embeds a complex system, almost taking the home...
By JamesPa , 1 hour ago
-
RE: Grant 13kW Aerona3 - issues getting zones to temp
Thanks, patience is something I’m trying to ma...
By Crimson , 3 hours ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
2025 - now a record year of Solar PV Generation. Octobe...
By AllyFish , 6 hours ago
-
RE: Midea ASHP – how to set weather compensation
@pash44pump - AI may have its uses (and I sort of allow...
By cathodeRay , 8 hours ago
-
RE: Mitsubishi Ecodan R290 10kW performance
Totally agree that any system is reliant on the ability...
By Sheriff Fatman , 8 hours ago
-
British Gas Heat Pump Installation Complaint
In 2024, my wife and I thought that we would try to do ...
By BGNO , 9 hours ago
-
Erm... no we can't! The issue first raised by the OP ...
By Transparent , 10 hours ago
-
RE: Is it mad to think there should be a minimum SCOP for UK heat pump installs?
This wouldn't solve the problem @mars is trying to solv...
By JamesPa , 10 hours ago
-
RE: Who has a V2G EV installation
I have PV, ASHP, UFH, Battery storage and no Gas (yaay ...
By AgentGeorge , 12 hours ago
-
RE: Testing new controls/monitoring for Midea Clone ASHP
Thx, but Sven did the hardware development. My role (as...
By Mosibi , 22 hours ago
-
RE: PV Panels on roof in Conservation Area
@majordennisbloodnok Fnaargh, I was thinking about try...
By colinc , 23 hours ago
-
RE: Electricity price predictions
@jamespa Ah, you mean MPs that have not pro...
By Batpred , 1 day ago
-
RE: Buying large amp bidirectional RCD and RCBO
Exactly @transparent , this type of RCBOs are not easil...
By Batpred , 1 day ago
-
RE: Very Much Awake – Renewing the Heating Industry One Step at a Time
I feel that that attitude shared by Aadil from Heat Gee...
By Toodles , 1 day ago
-
RE: The Hidden Secret to a Successful Heat Pump: Pipe Size Matters
and we have some of the strongest tidal flows anywhere ...
By Old_Scientist , 1 day ago



