Posted by: @afarmery

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I have a new Ecodan setup in an old granite cottage (insulated as best we can) with UFH.

My installer, who claims to know everything about ASHPs, has set the system so that it comes on between 0600 and 0900.  Then it's off until 1600 and then runs until 2200, then off overnight.  I know this because the Tesla app tells me there's 1.1 kW of power being used at these times (and there's no other appliances on at the moment).

I think I've understood from this forum that the system would be best in open loop, without thermostats or timers.  That being the case, how do I 'set back' the temp overnight without relying on stats?  Can I do this by programming the Ecodan to shift its heat curve by a small amount overnight?  Should I diable the timers and set the stats to a couple of degrees higher than I want the temp to be?

Thanks

 

A

@afarmery

You can't programme in changes to the WC settings unfortunately.  You either use stats or have the timer switch it off.  I've used external stats for a setback and it works OK for a modest setback of 2-3 degrees. You may have to tweak the WC curve to ensure the house warms up after the setback but you may also have to use the stats to limit the room temp when it's not set back. It will require a bit of trial and error.  Whether it saves money is a subject of some debate.  I think it does for me. 

I'm assuming you have non-Mitsubishi stats...

If you have an Ecodan then using the Mitsubishi wireless room controller and MelCloud makes programming in a timer to set desired room temps and a setback a breeze. Auto Adaption handles the rest.

@abernyte Thanks.  The installer fitted 3rd party stats (Heatmiser) and 'lost' the Ecodan WiFi interface, so looks like I'll have to purchase both the WiFi module and a wireless controller to do it this way via Melcloud.  

Am I right to infer that since my Ecodan is using a constant power of 1.1kW for the two blocks of time it's programmed to come on for, that it's not using the curve?  I would have thought that if it was using the curve, the power consumption would be variable depending on outside temp?

@abernyte  can you explain or link to the procedure please?

Open Melcloud - select your device - click Actions(button top right) - select Timer and programme what ever seasons you wish, with what ever settings you wish, at what ever times you wish.

@abernyte 

Looking at it I've been too nervous to press the continue button in case I screw up lol.

On the first screen when adding an event and selecting every day. Does the next screen give the option to set a temp'?  i.e. > every day > 2200 start > 0400 finish with a set temp' between those times?  I need to grow a pair and give it a go but this is the wrong time of year to screw my system.

Yeah when you continue it takes you to the system screen where you can set the temperature or DHW on/off. After you have programmed all your settings it needs you to click to commit the schedule to the cloud where the setting are pulled from. If you internet fails and it can't get the setting it reverts to the radio connection between the room temp controller and the unit and follows what ever temp is set manually there.

@abernyte that's excellent thank you.  I shall give it a proper looking at later. 👍

I have set out the whole year in seasons. Spring - Summer Autumn - Winter - Proper winter.   With a programmed schedule of gradual temp increase in the morning after set back over night and gradual cool down in the evening to set back.  Everything low and slow.

Posted by: @afarmery

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@abernyte Thanks.  The installer fitted 3rd party stats (Heatmiser) and 'lost' the Ecodan WiFi interface, so looks like I'll have to purchase both the WiFi module and a wireless controller to do it this way via Melcloud.  

Am I right to infer that since my Ecodan is using a constant power of 1.1kW for the two blocks of time it's programmed to come on for, that it's not using the curve?  I would have thought that if it was using the curve, the power consumption would be variable depending on outside temp?

Even if you are using fixed flow, it should still take more energy to heat your house if it's colder outside.  

This video explains the different heating modes and how to select them

Posted by: @abernyte

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I have set out the whole year in seasons. Spring - Summer Autumn - Winter - Proper winter.   With a programmed schedule of gradual temp increase in the morning after set back over night and gradual cool down in the evening to set back.  Everything low and slow.

@abernyte  Would it be possible to see a screenshot of a page to give me an idea of what it should look like as I tackle mine.