Posted by: @alec-morrow

internet failures are rarely  excessively long. [...] Im always amazed by how people in the U.k. would rather find fault with what’s on offer rather than try and understand how things actually work.

Asking "what happens if ..." is part of trying to understand how these things actually work!

Also, I'm amazed by how some people still don't seem to accept how bad internet connectivity is in some UK villages. Call it rare if you like, but it's not exactly unknown for an underground section to flood or a cabinet to get taken out by a road vehicle and internet connectivity to be missing for days until the drainage/wiring is repaired and/or equipment replaced. If I'm home, I could reroute internet over the mobile networks but that is often heavily restricted.

So, I think it's vital that any UK-deployed "smart" controller's on/off decisions can be overridden and it doesn't only "runs to the transmitted parameters", but that still risks it getting cold before someone reaches the interface. It's desirable and better for it to fail safe if it loses connection to its mothership. It would be nice if reviews would test and mention this important feature.

@mjr

You are perfectly correct, which is why I asked the question.

Industrial control systems are designed to 'fail-safe' for obvious reasons, and having the failure of one sensor (even a very important one) out of possibly several thousand, would have to be extremely dire for it to cause a major problem or a shutdown. This would normally have been engineered out by the use of a 2 out of 3 voting system.

Whilst many control systems may now be controllable via the internet, it is normally only the adjustment of settings that is allowed, actual control is still kept within the actual control system hardware.

It is therefore important that any home heating controller, retains and operates to the last acceptable input from any external source, be it over the internet or otherwise.

I've literally just changed my 2 grant Aerona to default weather compensation to see if it makes a difference to consumption, thanks for advice given by some helpful people on this site.

However what I am trying to get my head around is:

1. Hive thermostat set up on installation. Do I leave this at my current 19 degrees?

2. The hot water is programmed overnight by a separate timer connected to the cylinder while I'm on overnight cheaper tariff, and then programmed by the hive to top up a couple more times through the day for an hour. 

My question is when the pumps heat the water, the radiators lose some of their heat and then have to spike again. Is my set up wrong? Or is it because it's programmed through 3rd party thermostat?

3. Both the grant controllers set up for pump 1 and 2 show different outdoor and indoor temperatures only marginally between .5 and 1 degree. Does this matter?

Posted by: @bretix

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I've literally just changed my 2 grant Aerona to default weather compensation to see if it makes a difference to consumption, thanks for advice given by some helpful people on this site.

However what I am trying to get my head around is:

1. Hive thermostat set up on installation. Do I leave this at my current 19 degrees?

No. Turn it up to 25 or so.  The idea is to see how how the WC curve makes the house then change it if it gets too hot

2. The hot water is programmed overnight by a separate timer connected to the cylinder while I'm on overnight cheaper tariff, and then programmed by the hive to top up a couple more times through the day for an hour. 

My question is when the pumps heat the water, the radiators lose some of their heat and then have to spike again. Is my set up wrong? Or is it because it's programmed through 3rd party thermostat?

That's normal and how I'd do it if I were on a cheap rate.  Heating stops when HW runs. If you're not using much, HW will only be actually heating for less than an hour. 

3. Both the grant controllers set up for pump 1 and 2 show different outdoor and indoor temperatures only marginally between .5 and 1 degree. Does this matter?

I don't know for sure but I wouldn't think that variation matters in the scale of things.

Let us know how you get on. 

@kev-m it has made a difference to my electricity use. I've probably tightened up too much on hot water requirements so will be looking at those settings more. Just discovered hughf has posted the instructions for the chofu pump which has way more detail so will be exploring those for the hot water side of things.

This is a fascinating topic for any Heat Pump owner who is even slightly curious in getting the maximum efficiency from their device. Thank you to those knowledgeable posters who have provided the information.

I have a Mitsubishi Ecodan 14kW with a FTC5 and PAR-WR51R-E wireless controller heating radiators. Since installation the system is set to Auto Adaption mode and has worked flawlessly in heating my 180m2 1992 built timber framed house through periods of serious cold wet and windy weather in North East Scotland. 

The installer said that Fixed Flow was only used for commissioning, Weather Comp Curve was too slow to react in our exposed location and that Auto Adaptive setting would give me the best of all worlds in that it auto-magically tweaked the curve on the fly to maintain a comfortable house. In terms of costs is has been more successful than I had ever hoped in reducing the energy bills by around 60% from LPG, electrical heaters and solid fuel used previously. According to the FTC5 my flow temps seem not to vary greatly from between 33C and 36C, even in the depths of winter. My 2022 stats show I consumed 6400kWhs for whole house heating and hot water use which I do not consider bad (perhaps naively) with an overall COP of 4.2

My reading here suggests that weather compensation is the way to go but is there really going to be much difference and savings over my current setup?

Posted by: @abernyte

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This is a fascinating topic for any Heat Pump owner who is even slightly curious in getting the maximum efficiency from their device. Thank you to those knowledgeable posters who have provided the information.

I have a Mitsubishi Ecodan 14kW with a FTC5 and PAR-WR51R-E wireless controller heating radiators. Since installation the system is set to Auto Adaption mode and has worked flawlessly in heating my 180m2 1992 built timber framed house through periods of serious cold wet and windy weather in North East Scotland. 

The installer said that Fixed Flow was only used for commissioning, Weather Comp Curve was too slow to react in our exposed location and that Auto Adaptive setting would give me the best of all worlds in that it auto-magically tweaked the curve on the fly to maintain a comfortable house. In terms of costs is has been more successful than I had ever hoped in reducing the energy bills by around 60% from LPG, electrical heaters and solid fuel used previously. According to the FTC5 my flow temps seem not to vary greatly from between 33C and 36C, even in the depths of winter. My 2022 stats show I consumed 6400kWhs for whole house heating and hot water use which I do not consider bad (perhaps naively) with an overall COP of 4.2

My reading here suggests that weather compensation is the way to go but is there really going to be much difference and savings over my current setup?

Hello @abernyte and welcome.  I'm very interested in your setup as it's similar to mine (I have FTC 6 but I don't think there is a lot of difference).  I haven't tried auto adaptation properly yet but will soon.  I have heard it takes a week or two to 'learn'.  That's quite a low flow temp for radiators btw. What sort of indoor temps do you have?   

We have set it to 18C in morning rising to 19C lunchtime and 20C in the evening with a 15C set back overnight.  I have set various slight tweaks to this depending on the season but broadly the same.

Posted by: @abernyte

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This is a fascinating topic for any Heat Pump owner who is even slightly curious in getting the maximum efficiency from their device. Thank you to those knowledgeable posters who have provided the information.

I have a Mitsubishi Ecodan 14kW with a FTC5 and PAR-WR51R-E wireless controller heating radiators. Since installation the system is set to Auto Adaption mode and has worked flawlessly in heating my 180m2 1992 built timber framed house through periods of serious cold wet and windy weather in North East Scotland. 

The installer said that Fixed Flow was only used for commissioning, Weather Comp Curve was too slow to react in our exposed location and that Auto Adaptive setting would give me the best of all worlds in that it auto-magically tweaked the curve on the fly to maintain a comfortable house. In terms of costs is has been more successful than I had ever hoped in reducing the energy bills by around 60% from LPG, electrical heaters and solid fuel used previously. According to the FTC5 my flow temps seem not to vary greatly from between 33C and 36C, even in the depths of winter. My 2022 stats show I consumed 6400kWhs for whole house heating and hot water use which I do not consider bad (perhaps naively) with an overall COP of 4.2

My reading here suggests that weather compensation is the way to go but is there really going to be much difference and savings over my current setup?

I suspect that your installer is one of the few with the relevant knowledge of how to commission a heat pump correctly.

I think that your system is using a combination of weather compensation and auto adaptation, which should provide the best overall accuracy and efficiency. If you are achieving an overall COP of 4.2, you should be very pleased. I would not suggest changing anything.

Thank you, that is good to know and matches what my "gut" instinct was telling me but you know what "fear of missing out" is like!  Yes, the radiators are rarely anything other than tepidly warm to cold and the installer spent some time matching the rather larger radiators to each room compared to the old microbore ones they replaced. During commissioning we drew his attention to the lack of heat to touch in the rads and yet the house was uniformly warm. He just smiled and said "white mans magic".

sounds like it is working in weather compensation already..

it indeed fascinating how much heat there us in luke warm water in rads

I rather suspect you remembered something different from what he said!

Posted by: @mjr

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but it's not exactly unknown for an underground section to flood or a cabinet to get taken out by a road vehicle and internet connectivity to be missing for days until the drainage/wiring is repaired and/or equipment replaced. If I'm home, I could reroute internet over the mobile networks but that is often heavily restricted.