Posted by: @allyfish

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Good luck. From my experience here's the hit list for a Grant G1 installer:

1. Ensure the installers use the Grant controller that comes with the Aerona3 as the master thermostat and system controller. Fit it somewhere where it can control and it is accessible, main lounge, hallway, etc. Do not allow them to bury it away in the garage/plant room and connect some dumb on/off 3rd party Hive, Nest, Tado of other thermostat to it. They are not suitable for ASHP control despite Grant G1 installers routinely fitting them. The Chofu/Grant ASHP controller can do 7 day programmed CH and HW, quiet mode, low energy overnight tariff consumption, and all manner of clever things with the appropriate peripherals connected. It's a bit complicated for the user interface, but well worth the investment of time to get to know your way round. It's vastly superior to every other 3rd party CH and HW controller on the market.

2. Resist installation of a low loss header on the circuit unless one is needed for zoning UFH and radiators. If they fit a LLH, ensure they properly balance primary and secondary sides, a visual flow meter is required on each side! The pump in the ASHP unit will probably need to be set to lowest speed if a secondary circulating pump is installed. 

Hello everyone. I'm another noob and in the process of having a new house built which will have a Grant Aerona 3 17kW ashp. I'm keen to get the install done nicely and have been reading a fair amount so far but it's quite a lot to take in!

Looking at the two points here I'm not sure if I'm reading that the controller can also be a thermostat for the CH or if it needs to have something else attached. If so what would this be if it's not a Hive/Nest?

For point two, I see that a LLH should be resisted but how will I know if I can get away without one?

Sorry for jumping in here. Let me know if you think this should be a new topic/topics.

Hello. So this will be our first full winter with the ASHP. It was installed around the 20th of January last winter and has been fine. One slight issue with water tricking from the cylinder through the outflow but Grant sent an engineer to repair.

into our first full winter now. Temp is 0 degrees outside and the downstairs is currently and average of 19.67 degrees across the various zones, though the wood burner was on low in the living room earlier. Downstairs is underfloor heating. 

Upstairs currently 19.4 degrees. 

it all feels very comfortable but I don’t think I could get it warmer even if I wanted to when the temp drops below zero. This is due to the pump breaking off from heating at regular intervals to defrost itself. 

above zero, no issues but below zero it struggles. I say struggles but I guess I mean it’s limited by frost cycle although its limit is a comfortable home. It seems I did not have a low loss header installed which I thought was part of the package so will talk to the installer when they come to service it. I don’t know if it is of real benefit or not.

at -6 I woke up last week to find the house mostly in the 18s and 19s which I guess is ok.

I’m on octopus tracker so the electricity use so far is marginally cheaper than I paid for oil some years. I also have solar, battery and an Eddi so during a third of the year we there’s no real energy bill other than the accursed Standing Charge. 

Perhaps I would need to have the house running warmer ahead of any cold snap because when the outside temp drops below zero that’s when the defrost cycling issue kicks in and what it seems to do then is just hold the indoor temperature rather than increasing it any. 

Another frosty night. Woke to an average downstairs temp of 18.1

upstairs 18.0.

it needs to do better than that. If it can’t do better than that below zero because of the frost cycles there is a problem. Going to see if I can bring my service forward.

@marvinator80 Who are you getting to service? Do you have a local engineer, or are you going to Grant via their "annual service plan"?

@mikefl the installer say the will service for Grant as G1 installers. Have messaged them to see if I can bring it forward as we are going on 11 months.

Have also ordered a digital room thermometer to make sure my Wunda UFH display temps are accurate. Upstairs is on Hive, I do think that is accurate. Showing 17.8 at the moment but opposite end of the house upstairs colder. Trying to balance the radiators.

@marvinator80 I get Grant to come and service once a year. You don't need a service plan with them, just book one whenever you want. tbh I don't think they do much - the last visit this summer the guy spent most of his time cleaning the ashp. I discussed with him the horrendous electrical consumption during "cold" (ie below +5C) spells but he didn't proffer any solutions.  It's useful to have a recent service report on file though. It means, when I sell up, I can honestly say yes, (in response to queries before contract) when asked if the ashp is regularly serviced.  I also have a waste treatment Klargester (we are off mains drainage) with an actual service contract. They at least do a proper mechanical inspection and replace worn parts (ie preventive maintenance), without me having to raise any issues (there have been none).

Mike

@mike-patrick I called Grant HQ. They arranged for Olly the local service engineer to attend. Pricey service of the ASHP and system cylinder at £250. Condition of the warranty however. My old oil boiler used to cost me diddly squat to service, but a small fortune to run in oil! 😉

Posted by: @allyfish

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@mike-patrick I called Grant HQ. They arranged for Olly the local service engineer to attend. Pricey service of the ASHP and system cylinder at £250. Condition of the warranty however. My old oil boiler used to cost me diddly squat to service, but a small fortune to run in oil! 😉

Have you asked 'Diddly Squat' if he also does heat pumps? 😋 

@derek-m Perhaps Diddly Squat might also supply energy…

Just coming across this thread and its very informative. Thanks in particular to @allyfish for all the detailed info. I have recently had a similar install in the last few months. I had looked into ASHP a bit prior to the install but certainly not to the degree covered in this forum. All very interesing.

I have a Grant Aerona 10kw ASHP, 5.2kw solar and a 5.6kw battery.

I'm happy with the system overall but always looking to see how to optimise it as best as possible. I have seen suggestions on points of the install to check and as far as I can tell most of these comments are not issues (I think)

I'm hoping to adjust flow temps and timings for HW to increase overall efficiency and reduce bills. I previously had a hive thermostat with my gas boiler and I have just ordered a google nest before reading this thread (Doh). I see @allyfish's previous comments about 3rd party controllers and wondering if it is totally unnecessary. Even if from more of a monitoring stand point? Does it completely override the grant controller if installed?

Any thoughts would be appreciated.

Also if there were any step by step suggestions on optimising this particular system, that would be amazing.

Cheers,

Ian