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ASHP Cut-off Temperatures: What's Your Setting and is a Your Heating Still On?
I recently came across an interesting piece of information regarding air source heat pumps where the "accepted" ambient outdoor temperature at which ASHPs are designed to automatically turn off is 18C. Does anyone have this automated – ours isn't automated. If it is automated, at what ambient temperature does your ASHP shut down?
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Not seen a setting on our ASHP for auto cut-off temp. I normally turn it off manually for heating (not DHW) at the start of May and back on again at end of Sept, but as its manual then I can be flexible either way. Since install in 2015 ours has been set to maintain a constant 21C 24/7 from Oct to April and this works well.
My HP is set to "not supply any heat" above 19C external temp i.e. that's the top end of the WCC and above that it'll not run the pump. This isn't "off" though as the room stat might still be calling for heat, and so the internal pumps etc. will still be circulating water. Although at 19C outside I'd hope the house is warm enough.
I'm about to enter (hopefully!) summer #2 with it. I just left it running throughout the year (for CH and HW) - mostly it was doing nothing apart from the odd, chilly night, using <2 kWhs a day.
Grant Aerona 3 10kW
I don't have auto turn off either but manually change it over to cooling the UFH if its gets too hot in the summer
The Samsung controller does not have an automatic cutoff and I have set mine to 16C. The heating is still on and I just leave it to do its thing and let the smart thermostat make the decisions 🙂
5 Bedroom House in Cambridgeshire, double glazing, 300mm loft insulation and cavity wall insulation
Design temperature 21C @ OAT -2C = 10.2Kw heat loss, deltaT = 8 degrees
Bivalent system containing:
12Kw Samsung High Temperature Quiet (Gen 6) heat pump
26Kw Grant Blue Flame Oil Boiler
4.1Kw Solar Panel Array
34Kwh GivEnergy Stackable Battery System
It’s a bit nuts. May 4th today, and our central heating is still coming on in the evenings. Crazy. Whose heating is still coming on?
🔥 Britain’s Heat Pump Shitshow
How Installing a Heating System Became a National Nervous Breakdown
Free UK shipping.
📗 Heat Pumps Explained
A Jargon-Free Guide for Homeowners
Rewritten and updated for 2027
📘 From Zero to Heat Pump Hero
🛠️ Bodge Buster
New to heat pumps?
Take the Heat Pump Fundamentals course and use INTRO50 at checkout for 50% off.
Mine is still coming on.
Retrofitted 11.2kw Mitsubishi Ecodan to new radiators commissioned November 2021.
14 x 500w Monocrystalline solar panels.
2 ESS Smile G3 10.1 batteries.
ESS Smile G3 5kw inverter.
@lechillou maybe I am misunderstanding, I thought the thread was referring to a designed in cutoff of 18C that cannot be adjusted. The field setting you refer to is indeed what I am setting to 16C which I have recently turn down to 15C. 😀
5 Bedroom House in Cambridgeshire, double glazing, 300mm loft insulation and cavity wall insulation
Design temperature 21C @ OAT -2C = 10.2Kw heat loss, deltaT = 8 degrees
Bivalent system containing:
12Kw Samsung High Temperature Quiet (Gen 6) heat pump
26Kw Grant Blue Flame Oil Boiler
4.1Kw Solar Panel Array
34Kwh GivEnergy Stackable Battery System
@editor ours occasionally comes on in the morning if its been a cold night, 6 - 7C recently. The sun warms the house sufficiently during the day which the heat seems to last until bedtime most evenings thankfully 😀
5 Bedroom House in Cambridgeshire, double glazing, 300mm loft insulation and cavity wall insulation
Design temperature 21C @ OAT -2C = 10.2Kw heat loss, deltaT = 8 degrees
Bivalent system containing:
12Kw Samsung High Temperature Quiet (Gen 6) heat pump
26Kw Grant Blue Flame Oil Boiler
4.1Kw Solar Panel Array
34Kwh GivEnergy Stackable Battery System
Similarly, internal stat is set to 17C and occasionally fires up briefly in the morning. Solar thermal is now doing the DHW, tank 60C + most days. Solar gain, should we be that lucky, raises the house temp.
@technogeek Our Homely controller turns the heating on for perhaps an hour sometime between midnight and six in the morning, today (wall to wall sunshine at the moment) I would imagine it will be getting some zeds in until perhaps 20:30 or so, then stay on for two - three hours, just topping up heating occasionally. Regards, Toodles.
Toodles, heats his home with cold draughts and cooks food with magnets.
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