# Grant Aerona R290 - space heating advice and settings **URL:** \ **Category:** Heatpump\ **Tags:** grantr290\ **Created:** [9 October 2026 15:30 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435 "2026-10-09T15:30:24Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![riwaller](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/r/13edae/32.png) [@riwaller](https://community.openenergymonitor.org/u/riwaller)\ **Post date:** [9 October 2026 15:30 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/1 "2026-10-09T15:30:24Z")
As we get into the heating season, I’d be interested to learn from others about how best to optimise the Grant Aerona R290 ASHP and to find out what other settings folk are using. I’ve got a 6.5 kW unit and I’m currently using the following settings: - 20ºC daytime temp with a 18.5ºC overnight setback - Heating curve 0.8 - Room temp correction 2.0 - Circuit temp correction 3.0 (Worth adding I’ve been trying to run on silent mode 1) One of the issues I’ve noticed is that it doesn’t seem to reduce it’s output to allow the house to cool towards the overnight setback so I’ve ended up using the pump blockade setting overnight to prevent the house from staying too warm and annoying my wife! Maybe that’ll change as the nights get colder. I’d always thought the name of the game was to run the ASHP constantly at as low a flow temp as possible and at times this seems to work well and provide a decent COP. Here’s an example from this morning: ![Screenshot 2026-10-09 at 16.26.07](https://community.openenergymonitor.org/uploads/default/original/3X/a/4/a4d5712680353508820d1012e9c7c630bf8dfe03.jpeg) But at other times, the heat output is much more variable. Here’s this afternoon when the outside temperature is higher and the flow temperature is lower: ![Screenshot 2026-10-09 at 16.27.28](https://community.openenergymonitor.org/uploads/default/original/3X/8/6/8686af5bb376bfa6a748818a2da29307919637dd.jpeg) In short, any guidance on settings and how best to optimise very much appreciated! ---
**Author:** ![Johnmo](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/j/df705f/32.png) [@Johnmo](https://community.openenergymonitor.org/u/Johnmo)\ **Post date:** [10 October 2026 11:49 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/2 "2026-10-10T11:49:56Z")
> [@riwaller](#): > > Worth adding I’ve been trying to run on silent mode 1 Does that make any difference in steady state running, can see it making a difference during ramp up but once at target temperature not much. The other thing is it de-rates the output, so on a cold day you may not have enough output to warm the house or it will.slowly get get cold and cold inside as the heat pump struggles. If your heat pump is sized correctly I would operate in normal mode and let the heat pump controller do it’s own thing. Instead of trying to chase your tail with getting house to cool overnight why not just run the bedroom cooler always, and just let the heating tick away? And/or get a thinner quilt, or open the window in the bedroom an hour so before you go to bed? How is your bedroom heat regulated? > [@riwaller](#): > > But at other times, the heat output is much more variable. Here’s this afternoon when the outside temperature is higher and the flow temperature is lower: Output of the heat pump will vary it has way less work to do as heat losses reduce or you start to get the sun having an effect. ---
**Author:** ![riwaller](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/r/13edae/32.png) [@riwaller](https://community.openenergymonitor.org/u/riwaller)\ **Post date:** [11 October 2026 06:34 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/3 "2026-10-11T06:34:04Z")
Many thanks for the reply. In answer you your questions, I’ve been running in silent mode 1 during the day primarily for noise issues. I wouldn’t say it’s noisy, but my Grant Aerona R290 is more audible that I’d hoped for and certainly seems to be noisier that a Vaillant Arotherm+ that I’ve got experience of in a bolt hole I still have down in Stoke. I love the setting of the heat pump next to a boundary wall in the back garden from an aesthetics point of view, but in facing the rear of the house with a big wall behind it, I think that’s created a bit of a noise issue. Nothing too significant, just more audible that I’d like on a cool, still day. Find it whisper quiet in silent mode in contrast. But as you say fully anticipate having to run on “normal” mode as a matter of routine as the conditions get colder. ![IMG_8908](https://community.openenergymonitor.org/uploads/default/original/3X/d/2/d2266325f9f6f7e93e7ffd21169febebe1a7369f.jpeg) In terms of the heating strategy, that’s working well. Delighted with the thermal comfort. Just trying a very small (1ºC) overnight setback and the house naturally cools as I run a DHW cycle overnight in our cheap tariff window. Big concern from my wife all along was the bedroom being too warm. Successfully addressed by dialling back a TRV and opening the window! Guess I’m just overthinking things right now in being a bit of an energy geek and the ASHP and us entering our first heating season with an ASHP in the family home. Guess I just need to get through the first winter and see how it performs. ---
**Author:** ![Mart](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/m/e47774/32.png) [@Mart](https://community.openenergymonitor.org/u/Mart)\ **Post date:** [11 October 2026 07:35 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/4 "2026-10-11T07:35:17Z")
Looks like you have it pretty dialled in, curve and shift is going to be dependent on your own home. This will be my second winter. I learned a lot from mimicking @glyn.hudson. I’m currently running my 9kw R290 on a curve of 0.5 with a shift of 2. Its holding steady at about 20.5c. Having a flatter curve stops it ramping up and down over small temperature fluctuations so much. I’ll likely raise the curve later in the season. I don’t have an indoor thermostat so run completely off weather comp, your second graph looks like some kind of pump blockade wizardry but I can’t comment on that. I run it on silent mode 2 until it gets significantly colder. As Johnmo said eventually it can’t produce enough heat anymore to maintain temp, at which point I either move to silent mode 1 or run normally. The benefit of silent modes is it dampens the dramatic ramp up when it starts heating (and is quieter!). I’d suggest keep it in silent mode until it can’t supply enough heat to maintain the required indoor temperature, you’ll know when. Do you have an [emonTH](https://shop.openenergymonitor.com/emonth-wireless-temperature-humidity/)? I couldn’t see it in your data. I did experiment with setbacks as you suggested as I too like it cooler overnight but don’t currently bother. It takes a lot of energy to raise it early in the morning after a very cold night so my casual observations were that it wasn’t worth it. Its a personal thing I think. ---
**Author:** ![Cillian\_Cahill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/cillian_cahill/32/34667_2.png) [@Cillian\_Cahill](https://community.openenergymonitor.org/u/Cillian_Cahill)\ **Post date:** [11 October 2026 16:53 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/5 "2026-10-11T16:53:24Z")
When was your heatpump installed and last patched by Grant? My one was patched about three weeks ago and I find its not modulating like in did last April. Back in April it dropped back to 165w input and to under 1kwh out @15hrz. While it has dropped to 245w today, the output is staying over 2kwh. I know the below shows the min at 1126, but the was part of the oil recovery (which has also changed characteristics- not as aggressive now). As i have underfloor i normally run it at 0.4 and zero shift, but still trying to figure it out. The heat loss of the house is approx 3.5kwh @ -3. Didnt got with the 4kwh unit as i have a 300l cyclinder. @glyn.hudson - any info the latest Grant R290 patch? ![Screenshot_20261011_134420_Chrome](https://community.openenergymonitor.org/uploads/default/original/3X/2/e/2e7e0d3a699f3603fd88792a36cd8a908afbe64d.jpeg) ---
**Author:** ![glyn.hudson](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/glyn.hudson/32/35003_2.png) [@glyn.hudson](https://community.openenergymonitor.org/u/glyn.hudson)\ **Post date:** [11 October 2026 19:04 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/6 "2026-10-11T19:04:36Z")
What size is your heatpump? And what version number did you update from and to? - sent from my mobile device ---
**Author:** ![Cillian\_Cahill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/cillian_cahill/32/34667_2.png) [@Cillian\_Cahill](https://community.openenergymonitor.org/u/Cillian_Cahill)\ **Post date:** [11 October 2026 19:12 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/7 "2026-10-11T19:12:12Z")
I’ll ask the engineer tomorrow. I did look over his shoulder but it seemed to all be in Chinese. Only the outdoor unit got patched. The unit is the 6.5kwh version [HeatpumpMonitor.org](https://heatpumpmonitor.org/system/view?id=1153) He did say that its the lastest patch. The last patch was done in June. ---
**Author:** ![riwaller](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/r/13edae/32.png) [@riwaller](https://community.openenergymonitor.org/u/riwaller)\ **Post date:** [12 October 2026 20:58 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/8 "2026-10-12T20:58:11Z")
Thanks for a really helpful reply that’s encouraged me to flatten the curve a little bit more to 0.7, which has seen a noteworthy improvement in the performance and efficiency. I’ll see how we get on over the cooler weather over the weekend. Having got used to a Vaillant Arotherm+ with just one key heat curve setting to adjust, I’ve still yet to get my head round the combination of a heating curve and a shift. Something to experiment with over the coming winter season. Worth saying that the whole system design has mimicked that of @glyn.hudson 's - just have the smaller 6.5kW unit alongside the 250 litre super cylinder. ---
**Author:** ![riwaller](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/r/13edae/32.png) [@riwaller](https://community.openenergymonitor.org/u/riwaller)\ **Post date:** [18 October 2026 20:03 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/9 "2026-10-18T20:03:22Z")
Thanks for the message and sorry for the slow reply. Our install was in June. I did ask the lead installer to check the firmware when he was last up and he said it was the latest version. That’s a remarkable COP you’re getting. You must be chuffed with that! I knew underfloor heating works really well with heat pumps but I didn’t appreciated how much of a performance advantage it could provide. I’m happy with a COP above 4. Our big challenge has been all the 8mm microbore pipework in the house so for starters I’m happy that it’s working and keeping the house nice and warm in the first cold snap. Following @Mart 's reply, I’ve lowered the heat curve to 0.7 (zero shift) and that’s working well so far even with the recent drop in temperatures (first frost this morning). ---
**Author:** ![Cjl24](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/c/6de8d8/32.png) [@Cjl24](https://community.openenergymonitor.org/u/Cjl24)\ **Post date:** [19 October 2026 10:00 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/10 "2026-10-19T10:00:17Z")
Just looking at your system, it seems I might not be the only one with this strange high temp defrost behaviour (I suspect that your coil temp would show the same rapid drop off as mine just before the defrost). As you can see from the screenshot of your system on the 17th of October, like mine you get two defrosts in fairly quick succession at low heat demand and high ambient temp of almost 10 degrees. I’ve emailed Grant to see whether they can shed any light on it and if it’s correct behaviour as these kill the efficiency particularly at low outputs. Interesting one to watch. ![Screenshot 2026-10-19 at 10.57.14](https://community.openenergymonitor.org/uploads/default/original/3X/5/5/55621e8c36a6f0d6e63ca6c5bd701633aebd5033.png) ---
**Author:** ![Cillian\_Cahill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/cillian_cahill/32/34667_2.png) [@Cillian\_Cahill](https://community.openenergymonitor.org/u/Cillian_Cahill)\ **Post date:** [19 October 2026 10:35 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/11 "2026-10-19T10:35:36Z")
Hi Chris, They were my first defrosts of the season. I was surprised by both the frequency and the energy draw. It’s on my to-do list to compare it against other Grant and non-Grant systems to see whether mine is out of step. The defrost at around 07:20 is understandable, as you can clearly see the heat output declining beforehand. However, the one at around 08:00 is more interesting, as there doesn’t appear to be the same decline in heat output leading up to the defrost cycle. ---
**Author:** ![Cjl24](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/c/6de8d8/32.png) [@Cjl24](https://community.openenergymonitor.org/u/Cjl24)\ **Post date:** [19 October 2026 10:39 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/12 "2026-10-19T10:39:51Z")
Yes, they do seem rather trigger happy. I’d be surprised if the coil was frozen at 10 degrees ambient and low load but I suppose in the right conditions it’s theoretically possible. My 9kW has been behaving very much like the second defrost at about 08:00 your system had where you see a ramp in output and then a defrost. I’ll keep you posted if I hear anything from Grant. ---
**Author:** ![Cillian\_Cahill](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/cillian_cahill/32/34667_2.png) [@Cillian\_Cahill](https://community.openenergymonitor.org/u/Cillian_Cahill)\ **Post date:** [19 October 2026 10:51 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/13 "2026-10-19T10:51:30Z")
oh sorry - forgot to add, the temp used by OEM was +5-6 degrees over what I had locally. Here is the log from the heatpump - the temp is inline with my own external stat. Also, google had the temp correct - not sure what source they guys use for their weather data. ![image](https://community.openenergymonitor.org/uploads/default/original/3X/8/c/8cccd60ceef57bbc32932539fbc4f3aa735a6133.png) ---
**Author:** ![Cjl24](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/c/6de8d8/32.png) [@Cjl24](https://community.openenergymonitor.org/u/Cjl24)\ **Post date:** [19 October 2026 11:08 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/14 "2026-10-19T11:08:48Z")
Ahh that would explain it, doesn’t look particularly out of the ordinary in that case. Think I’m on my own again there! ---
**Author:** ![riwaller](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/r/13edae/32.png) [@riwaller](https://community.openenergymonitor.org/u/riwaller)\ **Post date:** [19 October 2026 12:58 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/15 "2026-10-19T12:58:16Z")
That’s interesting to see. Just as a comparison I’ve seen no defrosts on my heat pump yet and the external temperature dropped to 1ºC over the weekend… ---
**Author:** ![bontwoody](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/bontwoody/32/23897_2.png) [@bontwoody](https://community.openenergymonitor.org/u/bontwoody)\ **Post date:** [21 October 2026 13:48 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/17 "2026-10-21T13:48:27Z")
Can I jump in here and go back to the original post as I am helping a neighbour with trying to create a setback on their Grant R290. Night mode seems to be enabled in the schedule and the Night set back is shown in the current data window, however the room temperature stays at a constant 18C all day and all night. (Lines on graph from top down, flow temp, room temp, outdoor temp). ChatGPT seems to think there is a Decrease Water Temperature setting that reduces the WC curve temp during setback but I cant find it? ![image(2)](https://community.openenergymonitor.org/uploads/default/original/3X/5/9/59d8d66632704ee2f3c42854c8c877a9939fcc05.png) ![image(1)](https://community.openenergymonitor.org/uploads/default/original/3X/0/7/075db0c46eed83c949991f37b40e7b316e3e5cf8.jpeg) ---
**Author:** ![Johnmo](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/j/df705f/32.png) [@Johnmo](https://community.openenergymonitor.org/u/Johnmo)\ **Post date:** [21 October 2026 15:15 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/18 "2026-10-21T15:15:22Z")
Could the WC curve be a little to aggressive. Or it’s only getting down to 10 degs at night, maybe the house isn’t cooling enough even with a little bit of heat. Is the house heated by UFH? Maybe there is enough screed thickness that the heat within the slab is enough to keep the house hot (if 18 degs is hot, sounds cold to me). I tried setbacks with our house never worked, plus they save nothing anyway, as you have to play catch-up the next day running a more aggressive curve than needed. ---
**Author:** ![bontwoody](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/bontwoody/32/23897_2.png) [@bontwoody](https://community.openenergymonitor.org/u/bontwoody)\ **Post date:** [21 October 2026 15:32 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/19 "2026-10-21T15:32:38Z")
Im still playing with the curve John, but I doubt thats the issue as its pretty leaky at the moment and was cooling to 17C before I upped the curve. Its all radiators and 18C is too cool for me too. Its a fair point about whether setbacks actually help or not but I would like to know what the issue is here. ---
**Author:** ![Johnmo](https://community.openenergymonitor.org/letter_avatar_proxy/v4/letter/j/df705f/32.png) [@Johnmo](https://community.openenergymonitor.org/u/Johnmo)\ **Post date:** [21 October 2026 15:50 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/20 "2026-10-21T15:50:49Z")
Do you need to define in the control what the times are for day and night? ---
**Author:** ![bontwoody](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/bontwoody/32/23897_2.png) [@bontwoody](https://community.openenergymonitor.org/u/bontwoody)\ **Post date:** [21 October 2026 16:20 UTC](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435/21 "2026-10-21T16:20:04Z")
I think thats done John ![image](https://community.openenergymonitor.org/uploads/default/original/3X/3/0/306c02daaf80e959ec9bbf2e44209f1b5c056655.png) Although I am assuming its Circuit 1 thats the correct setting ![image](https://community.openenergymonitor.org/uploads/default/original/3X/4/8/48d4361d58251e545b448232950cadb4bf00cf94.png) [Next page](https://community.openenergymonitor.org/t/grant-aerona-r290-space-heating-advice-and-settings/30435.md?page=2)