@lucgw looks like you got the freedom heat pump warning sticker. Sadly it seems to be installed ironically as the settings are usually in no way the most efficient way to run a heat pump.

@lucgw you are welcome. Many of us are learning as we go. I can't help but notice there's no pipework insulation on any of that Grant install. Is the installer planning to revisit to do that? They should be! I really hope the outdoor pipework to and from the ASHP is well insulated....

I’ll see if I can jump on this thread today with some more information. The grant ashp is a capable machine, made in Japan by Chofu and the weather comp is decent. Grant will have installed it badly.

Attached, the original operating and programming manual for the Chofu controller, the unit with the sticker on the front. This is where you need to be making changes.

The Chofu controller will act as a room thermostat, and this is the optimum way to control your system. This will however require wiring and plumbing changes.

I've also attached the costings for my system from the Freedom toolkit - note that you will spend more money in the coldest months of the year.

@derek-m I've had a look at the LG Therma V big book and there's nothing at all about weather compensation. I've also realised that the cunning controls relating to water inflow temp are hidden behind the PIN controlled dashboard on the wall controller i.e. not supposed to be touched. However, I have the PIN and I've been faffing with it and been able to change the water temperature now. There's no user guide about any of this online for the LG pump that I can find either. There's a couple of YouTube videos and that's it.

And here is the Grant manual. Note that the grant manual makes extensive mention of the external heating controls, which serve to hide away the smarts from the user and make running costs high.

Posted by: @pumpo-sorcerer

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@derek-m I've had a look at the LG Therma V big book and there's nothing at all about weather compensation. I've also realised that the cunning controls relating to water inflow temp are hidden behind the PIN controlled dashboard on the wall controller i.e. not supposed to be touched. However, I have the PIN and I've been faffing with it and been able to change the water temperature now. There's no user guide about any of this online for the LG pump that I can find either. There's a couple of YouTube videos and that's it.

Hi Pumpo,

It would appear that your controller needs to be in AI/Auto Operation mode, as shown in the Owners Manual below.

LG apparently call weather compensation 'Seasonal Auto Temp'. Details of which can be found on page 164 of the Installation Manual below.

Ensure that the manuals are for your equipment.

Posted by: @pumpo-sorcerer

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@derek-m I've had a look at the LG Therma V big book and there's nothing at all about weather compensation. I've also realised that the cunning controls relating to water inflow temp are hidden behind the PIN controlled dashboard on the wall controller i.e. not supposed to be touched. However, I have the PIN and I've been faffing with it and been able to change the water temperature now. There's no user guide about any of this online for the LG pump that I can find either. There's a couple of YouTube videos and that's it.

If you have an LG Therma V, you might want to experiment with changing the 'Select Temperature Sensor' settng to 'air+water', which automatically mixes between Weather compensation (which is learns automatically, I think) and Load Compensation depending on the target room temperature. This does require the LG control panel to be wall mounted somewhere centrally in the house, not attached to the outside of your cylinder, in your garage.

For more info on LG specifics, have a look at this thread on buildhub: https://forum.buildhub.org.uk/topic/6385-lg-therma-v-mono-block-air-source-heat-pump/

LG therma V manual attached...

Lucas,

I've had a Grant ASHP of similar capacity for the last 6 years. We refurb'ed the house, inc with underfloor heating and all insulation done. It's about 1,500 sq.ft and a detached stone cottage.

Just to give you a basis for comparison we ran at 20 kWh per day in October and 29 in November [that's our total electricity use (about 8 kWh is background use from other appliances) inc the ASHP - we are a 100% electric house].

With the cold weather this month the figures have shot up to 50 - 60 kWh per day. By the way I'm expecting our total for the year to be about 10,500 kWh or 29kWh  average per day over the whole year - or 70kWh per sq.m per year.

A heat pump can't heat the house and the water at the same time. The time controller should be set to switch between water and heating during the day. How often it does this depends on how much hot water you use and whether or not you like to have hot water available at all times. You need to experiment with the timer to see what works best. If you try to heat both at once the pump will use masses of electricity and possibly still fail to give you hot water (we had this problem during a cold spell in January 2021)i

You mention the thermostat settings in each room. As another contributor said the ASHP should be controlled by weather compensation. This is a setting buried deep in the Grant controller which we mere end users are not supposed to touch. If needed, with help from the more technically skilled members of this forum, you can find out how to to do this yourself. The room thermostats are not there to switch the pump on and off in the way that they are normally configured with gas or oil fired central heating.

My overall experience is that even with an ASHP, electricity is an expensive option (I had no choice as there is no gas in our village and there was little room for an oil tank) for home heating. Relative to gas it was even when at a price of 12p per kWh. Others on this forum will have had a different experience and find their system (maybe including solar PV and storage batteries) very economical.

Good luck,

Mike

This is an interesting read. My Grant Aerona R32 13KW is going in shortly.

Our house is 294sqm, built in 2016 by us and well insulated timber frame construction with double glazing. Engineers calculated the heat loss at 9200Kw. 

our full downstair is underfloor heating and upstairs we are changing the radiators from K1 to K2, using the same fittings.

We are installing 5.46KW solar and 10KW battery also. 

I’m hopeful there is a lot in our favour there and the pump will do a good job and be economical to run compared to oil that we use currently. 

@marvinator80 put in more batteries - that would be my advice

I’ve said it before, Grant made these Aerona installs appear just like a boiler, because their fitters were used to installing boilers. Their plumbing and wiring are not the most efficient way to run these units.