Posted by: @danwright90

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After few days of trial and error, i found that FTC7 actually does not run on pure weather compensation and requires wired or wireless thermostat for each zone to provide room feedback/temperature.  (which i dont have)

I think it is most unlikely indeed that it cant run on pure WC, there will almost definitely be a config/wiring option to disable room influence entirely.  I dont have the FTC7 manual to hand (do you?) but it will with 99% certainty be there somewhere.

Posted by: @danwright90

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Looking at the zones on the FTC7, it is using its internal thermostat sensor for a reading/feedback. The issue is the FTC7 housed in cupboard and using room thermostat it, it is at 28c. 

Yes it does, like all heat pump controllers I know of, which is why the FTC7 (like all heat pump controllers) shouldn't be housed in a cupboard!  Unfortunately quite a few installers think that the thing to do is to add external controls and hide the heat pump controller itself from the user, which is simply not the case unless the external controls are heat pump specific (Homley, Havenwise or Adia currently being the only ones that are SOFAIK).

Posted by: @danwright90

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My thinking is to purchase the Ecodan wireless receiver, room thermostat

Thats certainly an option if the FTC7 cant easily be moved.  Alternatively (and what I would do in the first instance) disable room influence entirely and run on pure WC.  It might be in this part of the tree (heating/cooling) or it may be an installer setting. 

Perhaps there is an Ecodan owner on here who can be more specific.

Posted by: @danwright90

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Hi 

I have Ecodan 6kw with FTC7 packaged cylinder setup on two zone with EPH zone Values to control room temperature. 

Over the 6 months the COP was 2.5 for space heating. 

Taking advice from various sources, i wanted to see if i can improve the COP by lowering the weather compensation. 

After few days of trial and error, i found that FTC7 actually does not run on pure weather compensation and requires wired or wireless thermostat for each zone to provide room feedback/temperature.  (which i dont have)

Looking at the zones on the FTC7, it is using its internal thermostat sensor for a reading/feedback. The issue is the FTC7 housed in cupboard and using room thermostat it, it is at 28c. 

Looking for your help on what to do next.

My thinking is to purchase the Ecodan wireless receiver, room thermostat and MELCloud Hardware to allow the system see the true value but also give me more data on how the system and should improve the COP.

Hi, and welcome to the forums.

I'm a fairly new user of an Ecodan system (installed June 2025) with an FTC7.  I've been running on pure weather compensation since early December, having previously used Havenwise for heating control, and can confirm that it is driven by the outside temperature air sensor fitted somewhere around the heat pump, which I assume your's has.  You'll be able to confirm this if you're seeing any readings within MelCloud that show outside air temperature.

What makes you think that the weather compensation works differently to this on your system?

There's a separate Auto-Adapt mode available within the FTC7 options that does use internal thermostat readings as part of the overall picture, but the weather compensation curve works independently of this.

I've attached a screenshot of my system data for the last 24 hours (10kW Ecodan with FTC7), showing the set flow temperature, the outside air temperature and the room temperature from the internal Mitsubishi thermostat (this is set to a target of 27°C, so that it creates a constant demand for heat for the weather compensation to activate).  The changes in the flow temperature setting (red line) are triggered by changes in the outside air temperature setting (grey/black line).  The internal temperature (yellow line) fluctuates slightly around the 20°C mark whilst trying to achieve its target of 27.  It never reaches this point because the set flow temperature, being driven by the outside air reading, never allows it to do so.  The indoor thermostat is simply a measuring device, but has no influence on how the heat pump is running in this mode.

Posted by: @danwright90

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Taking advice from various sources, i wanted to see if i can improve the COP by lowering the weather compensation. 

After few days of trial and error, i found that FTC7 actually does not run on pure weather compensation and requires wired or wireless thermostat for each zone to provide room feedback/temperature.  (which i dont have)

 Changes may have been introduced on the FTC7 and my experience is with FTC6, but I have had some success with "pure" Weather Compensation on my Ecodan over a period of 2 years.

I was persuaded that "Adaptive" using a PAR 60 wireless room sensor would give even better results, but this has not been my experience.

I have experienced significant location and other problems with just with one sensor and I am not far from reverting to straight weather compensation. 

@jamespa, thanks for your reply. 

There is no way to disable room influence, Had to look at the settings, They call it room temperature control, and you got 3 modes, Fast, Slow and Auto. Right now its on Auto.

The installer place in the hot press at it was the most logically way to do it.

The installer placed 3rd party 2 zone thermostats, which will tell the heat pump that there is a requirement for heat.

To certain point i believe the setup of the heat pump and 3rd zone controller is correct and this is what signally to the heat pump to run when demand/heat is required. (On/OFF)

@sheriff-fatman 

Thanks for the reply. 

Mine was fitting in May 2025 but i do not have the MELCloud/hardware to get any readings from the system. I purely down to the FTC 7 Controller on the tank. 

The system is running WC and has outdoor temperature sensor but internally, i do not have any wireless ecodan thermostats in place in each Zone. 

The only way to control the heating is with Zone value controls which is linked to the heat pump which signal ON and OFF if there is demand for that zone. 

Looking at the Zone settings on FTC 7, it does use FTC 7 thermostat to balance the curve/flow temp. 

The real issue and with help ChatGPT, Because the location of Tank/FTC7 thermostat is place in warm area, it going to have negative effect COP which currently is 2.5.

To increase the COP, ideally an wireless ecodan thermostats should be place in each zone which will give a more accurate temperature reading of the house/zones.

What i am trying to nail down if others has experience this, is the FTC 7 thermostat sensor having a bearing/impact, is further settings need to be updated or more hardware to help the system work better

Once again, I've the FTC6. However, a bit of clarifying could be in order.

The actual flow temperature controller (the FTC7 or 6) is the bigger metal box with a screwed-on front and no controls, but with a circuit board inside and various wires going into it. The smaller box on the wall that has an LCD screen and buttons and stuff is the main remote controller unit and that box does, I believe, have a temperature sensor in it. The cable between the two is only a twin wire cable, so it is perfectly possible and straightforward for the FTC to be powered down (probably by turning the heat pump off), the wired remote controller to be resited, the wire to be rerouted to accommodate and for the whole to be reconnected before turning the heat pump on again. That would remove the issue of the warm cupboard without much disruption - assuming there's another suitable site for the little wall box reasonably near. Using a wireless remote controller is simply a means of achieving the same thing without rerouting a wire. It could work well, but wireless communication is always less stable than wired, so it's a probably rather than a definite.

@davidalgarve 

Thanks for the reply. 

It is trying to navigate/understand what the system is doing internally and if the FTC 7 thermostat is having an impact.

The FTC 7 does have DIP switch on board if 3rd controllers are being used. I wonder, if that is the case, is the FTC 7/heat pump running in pure weather compensation mode ? 

The signal from zone controllers/thermostats is in place but heat pump will run when the WC curve is met.

Posted by: @danwright90

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@sheriff-fatman 

Thanks for the reply. 

Mine was fitting in May 2025 but i do not have the MELCloud/hardware to get any readings from the system. I purely down to the FTC 7 Controller on the tank. 

The system is running WC and has outdoor temperature sensor but internally, i do not have any wireless ecodan thermostats in place in each Zone. 

The only way to control the heating is with Zone value controls which is linked to the heat pump which signal ON and OFF if there is demand for that zone. 

Looking at the Zone settings on FTC 7, it does use FTC 7 thermostat to balance the curve/flow temp. 

The real issue and with help ChatGPT, Because the location of Tank/FTC7 thermostat is place in warm area, it going to have negative effect COP which currently is 2.5.

To increase the COP, ideally an wireless ecodan thermostats should be place in each zone which will give a more accurate temperature reading of the house/zones.

What i am trying to nail down if others has experience this, is the FTC 7 thermostat sensor having a bearing/impact, is further settings need to be updated or more hardware to help the system work better

First of all, be very cautious about the relying on the reported COP figures, in isolation of anything else as an indicator of a system problem, as with each experience I read from fellow Ecodan users, I'm increasingly of the opinion that the true COP is potentially being under-reported.  Virtually all the posts I see regarding Ecodan performance have figures in the 2.5-3.0 range.  I'm struggling to get mine above a SCOP of 3.0, and yesterday it ran at a COP of 2.54 for heating in outside air temperature of -1.6°C.  Allowing for the fact that any heat pump will become less efficient as the weather gets colder, these are still low numbers, yet I'm seeing cost savings of around 55% on energy consumption compared to the equivalent gas boiler costs from last year.

Faced with the two possibilities of "Ecodans are terrible heat pumps" or "Ecodan reporting is understating the COP figure" I'm leaning increasingly toward the second of the two, albeit I'm very conscious that it's just a personal theory for now.

In your scenario, I'd be cautious about adding the Mitsubishi remote thermostat controllers, as you already have 3rd party ones in place, and the Mitsubishi ones are unlikely to be any more accurate than these, as they only report in 0.5°C increments.  The challenge you appear to have is that the system is installed with 3rd party thermostats, and that there are more than one of them, so the system setup is intended to be operated as two separate zones.  All of this puts barriers in place to the intention of running with weather compensation, which ideally should be run as a single zone throughout the house.  Adding Mitsubishi thermostats in their place would simply be switching the room reporting function from one device to another, but wouldn't help generate any improved efficiency in isolation.

Based on your comments, my interpretation is that the Ecodan specific cylinder you have is designed to have the FTC7 controller attached to it in that location, so this being next to the cylinder itself is presumably pre-designed by Mitsubishi and not intended to act as the primary indoor reporting thermostat for the system.  Logically, the installation should have included one of the portable Mitsubishi devices for that purpose, but your installer has used two 3rd party ones in place of this.  These look to be reporting devices only, so are not capable of sending data back to the FTC7 for it to use, so the FTC7 is defaulting to it's own sensor in the absence of this.

Consequently, if you want to be able to have better control over an internal temperature driven heating system then replacing the two 3rd party thermostats with a single Mitsubishi portable thermostat would assist with this.  However, this isn't what you are looking to achieve, based on your comments, as you want to operate on pure weather compensation.  To do this, you have everything in place already, as you have the outdoor temperature sensor, which is all that it should require.  Logically that means the challenge is a configuration issue to get it to run in weather compensation mode, and that should be feasible with the collective experience within this forum, of which @jamespa is ultimately one of the keenest minds, but doesn't have direct experience of the Ecodan heat pumps, so perhaps myself and others can provide this user insight as and where it's needed.

For now, I would hold off from purchasing any additional hardware until such time as we collectively fail to overcome the configuration challenge, as I currently don't see that it's needed.

Posted by: @sheriff-fatman

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Logically that means the challenge is a configuration issue to get it to run in weather compensation mode, and that should be feasible with the collective experience within this forum ...

For now, I would hold off from purchasing any additional hardware until such time as we collectively fail to overcome the configuration challenge, as I currently don't see that it's needed.

Very much agree with this!

Sometimes the way to get things to operate in pure WC mode is to set the curve on the controller, then just turn all the 'room temperature set points' (third party and if necessary on the controller) to max.  The heat pump then thinks that the demand isn't satisfied, so keeps pumping water at the WC setting which is what you want.  To get this to work you would of course need to ensure that there is no adaptive mode (where the heat pump modifies its own WC curve) operational.

Without an FTC7 in front of me I probably cant add a lot more, but for sure (well 99.9%) there will be a way to do it.

@sheriff-fatman 

Thanks for the reply

I hold off for now with the hardware but i may still get the MELCloud receiver as this would give me flow temperatures as right now, i am in the blind. 

I read in other forums that consumption values may not be correct, hence the low COP and true measurement is to place energy monitoring. 

For Grant system in Ireland, the system must be setup on two zones (dont understand the logic)

The installers are registered, highly recommended, so i do trust the install. 

I may need to give it more time with the curve and dialling in the settings to get a more complete picture.

When i started this project, it only seems to get more confusing. 

Posted by: @danwright90

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There is no way to disable room influence, Had to look at the settings, They call it room temperature control, and you got 3 modes, Fast, Slow and Auto. Right now its on Auto.

This is the part of your query that is currently puzzling me, as none of these modes are familiar to me from someone who has played around with the FTC7 on a regular basis.

I'm away from home currently, but will take a look this evening to see if I can find the settings you're referring to, and I should also be able to record footage to point to how I can set up and amend the WC curve from the FTC7 screen.  This sounds like it might be useful to figure out where the differences in set up currently are.