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Ecodan Room Temperature Mode

Peterr · 2022-03-14T16:42:34Z

Just wondering if there is anyone running their Ecodan in Room Temperature (Room Adaptation) Mode? If so, how are you finding it? We now have our system set up to use this mode, and, while it seems to work well for the radiators, it does not seem ideally suited to UFH, although there are a few compromises with our system as a result of the way it has been installed. The UFH is downstairs only and is split into 3 zones, each with its own thermostat. When one of these calls for heat, the UFH controller sends a demand to the FTC. So far, so good, but here is the compromise, the main FTC controller is located on our first floor landing next to the airing cupboard, and in order for heat to get from the ASHP to the UFH, both the UFH controller and the FTC controller need to be calling for heat! This means that in order for the UFH to work off the zone stats, the FTC controller needs to be set so that it is always on. I don't think this can possibly work correctly; there is no meaningful feedback from the rooms being heated to the FTC controller. One option is to get another Mitsubishi wireless controller and locate it downstairs, but I don't really want to shell out for this unless I know it's going to work. I was under the impression, perhaps wrongly, that in room adaptation, the FTC used some form of weather compensation to determine the flow temperature, perhaps depending on both the outside temperature and the difference between measured and demanded temperature? What we are seeing is the flow temperature going up to over 50C whenever the UFH is triggered, irrespective of the outdoor temperature. Very inefficient, when, even on the coldest nights, we never used to get above 43C in weather compensation mode. We have had some nice sunny days here recently, so the house gets nicely warmed by the sun during the day, meaning that the UFH is off from about 9.00 until probably 1.00 or 2.00 in the morning. This obviously means that the floor temperature (concrete slab) drops considerably, so the ASHP then has to work hard to get it back up to temperature before the rooms start getting heated again. I don't know if room adaptation mode, if it had the correct feedback, would preemptively kick the ASHP in to life to prevent the rooms dropping too much below the desired temperature. However, this would imply some sort of intelligence to predict how far the room temperature is going to drop based on the outside temperature - perhaps I'm expecting a bit too much! I'll probably try giving Mitsubishi a call to find out a bit more, but I am starting to think that straightforward Weather Compensation may the be best way forward.

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Air Source Heat Pumps (ASHPs)

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Derek M

(@derek-m)

Illustrious Member Member

Joined: 5 years ago

Posts: 4425

04/09/2023 8:33 pm

Posted by: @damijand

↑

@derek-m Inside inner unit (I don't know how it is called: inside metal box with FTC board )

If my memory serves me well, the Human Machine Interface (HMI) is often located on the main controller, which is usually placed in the airing cupboard or some other inappropriate location. I believe that the temperature sensing thermistor is located within the HMI, so therefore is not located within the room whose temperature is to be controlled.

I also believe that the HMI can be removed from the main panel and connected back to the main panel using a suitable extension cable. As Kev pointed out, it is also possible to purchase and install an external temperature sensor either hardwired or wireless.

It may be that when you select room temperature and DHW to be displayed on the HMI, it is actually expecting that one of these external sensors to have been installed.

I think that Kev researched this some time ago, so may be able to provide more definitive information.

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Kev M

(@kev-m)

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Posts: 1276

05/09/2023 6:41 am

Posted by: @derek-m

↑

Posted by: @damijand

↑

@derek-m Inside inner unit (I don't know how it is called: inside metal box with FTC board )

If my memory serves me well, the Human Machine Interface (HMI) is often located on the main controller, which is usually placed in the airing cupboard or some other inappropriate location. I believe that the temperature sensing thermistor is located within the HMI, so therefore is not located within the room whose temperature is to be controlled.

I also believe that the HMI can be removed from the main panel and connected back to the main panel using a suitable extension cable. As Kev pointed out, it is also possible to purchase and install an external temperature sensor either hardwired or wireless.

It may be that when you select room temperature and DHW to be displayed on the HMI, it is actually expecting that one of these external sensors to have been installed.

I think that Kev researched this some time ago, so may be able to provide more definitive information.

You may have to change the sensor settings in Initial Settings. I'm not at home so I can't check mine to see which it needs to be. I think you need it to be "Main RC" but not sure. Have a look on p 37 and 41 in the FTC manual.

https://library.mitsubishielectric.co.uk/pdf/book/Ecodan_FTC6_PAC-IF071-3B-E_Installation_Manual_BH79D843H02#page-40-41

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DamijanD

(@damijand)

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Posts: 18

05/09/2023 5:45 pm

Thx for replies. I am aware that HMI (Main RC as it is called in manuals) can be removed from the box (and that it can be used as a room temp. sensor).

Current placement:

I think that settings are correct:

(this is "Show temp:" and Room+DHW)

(this is "Setting for room sensor" and selected is "Main remote")

Room temp. is visible via MELCloud. But on the main screen it is not:

(it should be left from the DHW temp)

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Kev M

(@kev-m)

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Posts: 1276

06/09/2023 7:51 am

@damijand sorry, then I don't know why room temp isn't displayed. I'll ask on another group I'm on and let you know.

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Derek M

(@derek-m)

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Posts: 4425

06/09/2023 9:09 am

@damijand

I would suggest that you try each of the possible settings in turn, to see if any give the desired result.

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Kev M

(@kev-m)

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06/09/2023 10:28 am

Posted by: @kev-m

↑

@damijand sorry, then I don't know why room temp isn't displayed. I'll ask on another group I'm on and let you know.

I asked and this was the reply

Check that room and temp is selected in the controller. Go to menu, initial settings, temp display, then change to room and temp, press tick to save

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DamijanD

(@damijand)

Active Member Member

Joined: 3 years ago

Posts: 18

09/09/2023 9:37 am

I recorded video with settings and behaviour (and I changed UI to English before 🙂

As far as I can see everything that you suggested is already set.

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Kev M

(@kev-m)

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Joined: 5 years ago

Posts: 1276

09/09/2023 4:12 pm

Posted by: @damijand

↑

I recorded video with settings and behaviour (and I changed UI to English before 🙂

As far as I can see everything that you suggested is already set.

I missed this before but you need to put the system in room temp mode to display the room temp. Yours is on weather compensation and in that mode the room temp isn't displayed.

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DamijanD

(@damijand)

Active Member Member

Joined: 3 years ago

Posts: 18

09/09/2023 7:05 pm

Oh really (I knew that there is some stupid thing). Big thanks for this. - I tested it and it works.

But IMHO that limitation is stupid. I mean if I have Main RC in my living room I would like to see room temp regardless of heating mode.

What do you suggest Is it better to have on weather compensation or on room temperature (I don't know how good is this adaptation mode)?

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Kev M

(@kev-m)

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Joined: 5 years ago

Posts: 1276

10/09/2023 5:53 am

Posted by: @damijand

↑

Oh really (I knew that there is some stupid thing). Big thanks for this. - I tested it and it works.

But IMHO that limitation is stupid. I mean if I have Main RC in my living room I would like to see room temp regardless of heating mode.

What do you suggest Is it better to have on weather compensation or on room temperature (I don't know how good is this adaptation mode)?

Yes it does seem strange that is doesn't always display room temp.

I like auto adaptation. It's good to be able to vary the room temperature directly and (in my case) move the wireless controller around. It definitely keeps the house temp more constant than weather compensation alone and you can programme in temp setbacks, which you can't do with WC, other than switching off and on. It's also good at reducing cycling when it's warmer.

The downsides are it tends to run hotter and if you have temp setbacks its default is to raise the flow a lot (50 deg and more) to bring the room temp up. But you can adjust this with settings if you want. COP is slightly worse than WC but downtime is more so overall consumption is (IME) about the same.

👍

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DamijanD

(@damijand)

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Posts: 18

10/09/2023 7:28 pm

Thank you - your answers are very informative and helpful. Can you describe the settings that you mentioned in the last paragraf?

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Kev M

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Posts: 1276

10/09/2023 8:14 pm

Posted by: @damijand

↑

Thank you - your answers are very informative and helpful. Can you describe the settings that you mentioned in the last paragraf?

P38 of the manual in the link

https://library.mitsubishielectric.co.uk/pdf/book/Ecodan_FTC6_PAC-IF071-3B-E_Installation_Manual_BH79D843H02#page-38-39

I set the max-min to 20-43, the interval to 30 and the temp diff to +-5.

It's a bit of a mystery how AA actually works but these settings worked for me after a bit of trial and error. After you start up AA (or change the settings) it takes a few days for the system to settle down (the 'adapt' part of auto adaptation!)

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