@trungdong I don't how your indoor cylinder is doing but mine is located where most of the pipes and buffer tank is. It's quite hot in the room but I don't know if that is from lost heat from the cylinder or lost heat through lagged pipes and the buffer. but it's loosing heat from that equipment not the radiator because i've turned that completely off. How warm are other peoples plant rooms? It's 25'c in our plant/utility room now, and that used to be the coldest room in the house. It can't be measuring an indoor temperature from the indoor unit or it would be shutting off before 25'c. The rest of the house is also uncomfortably warm too, 24'c in the kitchen. I've now knocked down all TRV's to 2. I have emailed Aira to asked them if they could look at the weather compensation. The 2 radiators without TRV's measured 55'c with a IR thermomotor yesterday. The system was designed for a 45'c flow temp at -3'c outside, so we are way too hot for the time of year.

@mikeh, I have been in a similar unfortunate situation for the last two days (when the outdoor temperature dropped). The indoor sensor showed 26º on the app this morning, while the target temperature is 18º C! Something must be wrong here. I had to resort to disabling heating in the app (for now).
The temperature at the radiator also felt unnecessarily too hot, but I didn't have anything to measure it.
Aira is coming tomorrow to fit the thermostat; I'll check with the visiting technician and see what they say.

@trungdong It's good to know they are now retrofitting thermostats to customers though. Where abouts are you in the country? It's also interesting that your app shows an indoor temperature when mine doesn't.

@trungdong Aira came and fitted our thermostat yesterday. How are you finding the heating of your house since you got your thermostat? I now have in indoor temperature readout in the app that matches the thermostat. I have set the target temperature to 18'c in the hall. I was surprised to find that the the radiator was warm when I got home from the pub last night and the thermostat showing 21.5'c. It could have over shot but I don't' think the temperature dropped to 18'c or lower. I checked it a few times on the app while out, to see if the house temperature had dropped to 18'c, I never saw the temp below 21.5c. I think it's still coming on too soon. My old boiler wouldn't kick in until it was half a degree below target temp. Is it normal for a heat pump to start warming before the indoor temperature drops to it's target temperature? 

@mikeh Is there any ‘smart’ technology controlling the heat pump by any chance? There are some smart controls that ‘anticipate’ reduced energy cost tariff changes and there are also predictive temperature (OAT) algorithms that are trying to think ahead for you…? Regards, Toodles.

@toodles There is the new Octopus/Aira tariff but I've not opted for that just yet so I hope it's not trying to plan for that. But predicting for the weather may be what it's doing. looking on the app there is a message about weather optimisation. "Different houses are warmed up in different ways. Our system will learn over time how your house is affected by sunlight and other weather factors. We read the weather forecast at all times and continuously adjust your heating to minimise you energy consumption to ensure maximum comfort." It's not a setting that can be turned on or off, it's just a statement. The thermostat hasn't been in 24 hours so we'll see how it goes over time.
The technician who came was just running around fitting thermostats this week. He had not been told or booked with time to also test/balance the radiator, which hasn't been done yet or look at the weather compensation. TBF he called an hour before coming, on the off chance I'd be available. He just has a big list of customers and a van full of stats to work through. I'll call Aira to get another visit set up to test/balance the radiators. in the mean time, I've picked up some radiator thermomotors off Amazon and I'll have a go myself. The engineer said they have very little extra setting in their engineer app and have no weather condensation setting. So I'll be asking them who can adjust this?    

@mikeh If you wish to balance the radiators yourself, there is an article wot I rote at:

https://renewableheatinghub.co.uk/how-to-balance-radiators-the-role-of-the-lockshield-valve

I know there are other methods but this one works for me. 😉

I suspect that the Octopus/Aira tariff is Octopus Cosy in a different wrapper - does it offer you 2 x 3 hours and 1 x 2 hour slots at the cheapest rate and a very ‘spensive rate in the early evening? I am using Cosy and as I have 27 kWh’s of battery, I never need to use anything other than the cheapest 8 hours of the day to keep my system fully charged and powered. Regards, Toodles.

@mikeh I'm in the South (Hampshire).
I set the thermostat to 20º as I have to leave it in the dining room. Otherwise, it kept dropping off the (Bluetooth?) connection with the indoor unit. I have never seen the temperature readings on the thermostat drop below 22º.
Two nights when it was cold outside (4–6º), I woke up to a hot house with the thermostat showing 25º! Same in the app. I had to manually turn the heating off in the app. I wrote to Aira to ask for a solution but they haven't come back. It was warm the last few days, so I have not seen this again. My guess is the heat pump was trying too hard to compensate for the low external temp. However, it's just dumb to continue heating when the indoor temp is 5º above the target. I hope this can be fixed with a software/configuration update.
My radiators were not balanced either; I don't know if Aira will do it (as part of their installation process). Please let me know if you hear from them regarding this.
Cheers!

@toodles Thanks for the blog post. I've only balanced 4 radiators so far adjusting them to have a 5-6'c drop between flow and return. maybe I've been to strict in my approach so far. I'll keep going for now but see how it affects comfort and allow for a bit of flexibility if my approach if it isn't working out. I agree that the Aira tariff looks to be a copy of Cosy. I have solar but now battery so for now I'm sticking with octopus tracker.

Posted by: @mikeh

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radiator was warm

If the radiator feels warm the flow temp must be above body temperature. So your system is running very hot for the current temperatures. Is it set to weather compensation or fixed flow temp?
You really need to set the thermostat high and then fine fume your compensation curve. Then use the thermostat as a limit stop on the system.

@johnmo Aira gives you no visibility or control of flow temperature at present. The thermostat has basic functionality, there is no display on the indoor unit and most settings are via the app. But the app has limits settings, neither the customer or engineer can set a weather compensation. I am in contact with Aira's customer service team to get them to adjust the weather compensation remotely. The flow temperature I've been measuring when balancing over the last few days was 45'c. The highest radiator temperature I measured a few weeks ago was 62'c, that day it burned through about 30kwh of electricity and the house was baking hot.

@trungdong worth mentioning this reply to a 2 star review on google play store. "Thanks for your feedback! Sorry to hear that away mode didn't work, please contact customer support (phone number +44 330 822 5493). We are working on a number of the features you mention. Hot water scheduling will be released this week, scheduling for house heating in the upcoming month as well as electricity consumption."