Posted by: @editor

@batalto, we also asked for ours to remain in the utility room cupboard (where it’s always roasting) to replace the old controller. What irks me though is that instead of taking the easy option, the installers should should have advised us to place the controller outside the cupboard, or quite easily on the other side of the way in the main living area which would have given us more options going forward. They’re all small things that have an impact on the efficiency of the system.

Are their wireless rather than wired controllers for some heat pumps?

@jeff 

Mitsubishi can supply a wireless remote controller as an optional extra.

For other manufacturers you would need to check their website.

It also may be possible to install a wired or wireless temperature sensor, rather than a full controller.

Posted by: @derek-m

@jeff 

Mitsubishi can supply a wireless remote controller as an optional extra.

For other manufacturers you would need to check their website.

It also may be possible to install a wired or wireless temperature sensor, rather than a full controller.

Thanks. Would seem like a useful thing to invest in at the start for future flexibility  assuming the extra cost isn't huge. 

@derek-m 

Helpfully, it does a quick-view summary of the current month (I pressed F4 once, pressing again allows you to drill down into the data). If you go deeper into the menu system, it gives you the exact same figures. TBH, I think that my figures are not fully representative because of the energy that it took to bring my house back up to a liveable temperature & get everything started, but these are the figures that it gives:

Consumed electrical energy: 71Kwh
Delivered energy: 352Kwh

Coefficient of Performance (COP) = Delivered/Consumed

My Current COP = 352/71 = 4.96

What are reasonable COP figures?

@justinsb 

Ouch!

Further to the talk of thermostats & Temperature Sensors, I also have a wireless Honeywell T3M Programmable Thermostat jacked into the system. This would appear to be massive overkill, & seems to want to try & control the entire system itself - which obviously I don't want. Is it possible to "disable it" so that it doesn't try to take over?

From reading the above comments, it would appear that all I actually need is a (potentially wireless) Mitsubishi temperature sensor, rather than an additional, stand alone central heating controller?  I do, after all, have a rather expensive Mitsubishi system with a built-in, cloud based app run controller that is doing it all for me already...!

@justinsb,

if it's wired up like mine, all the thermostat does is call for heat when the room temperature drops below its set temperature. The ASHP starts up and pumps water round at a temperature as defined by your weather compensation curve and when the room temperature reaches the thermostat's set temperature, the thermostat stops calling for heat and the ASHP stops.  And repeat ...

The ASHP doesn't 'know' the room temperature.  If you want to let Mitsubishi control the system using room temperature, you need to ditch the 3rd party thermostat and, as you say, get a Mitsubishi wireless one, a temperature sensor or you can use the main controller but you'd neet to locate it somewhere sensible (i.e. not in the airing cupboard).  I assume if you do any of these, the Mitsubishi controller does something cleverer than just turn the ASHP off and on.  I think (I don't know) it will move the weather compensation curve  around or otherwise adjust the flow temps to get to the set room temp. 

To remove tour wireless thermostat permanently you'd need to disconnect it from the controller but temporarily you could just set it on manual and turn the temp up to 30.  That's what I've done.

The diferent options are explained on page 15 of the FTC6 manual

https://library.mitsubishielectric.co.uk/pdf/book/Ecodan_FTC6_PAC-IF071-3B-E_Installation_Manual_BH79D843H02#page-1

@morgan so you figures give:

COP = 466/175 = 2.66

How is your setup different from mine? Is there a forum page here that describes what you've got?

@justinsb 

I’ve got much the same as you apart from mine is an 11.2kw Ecodan.   It was only commissioned last Tuesday but it’s roasting here hence playing with settings.  It appears the room stat doesn’t communicate because the heating just keeps going.  To stop it I have to power it off at night.  Still awaiting a call back from the installer.

@morgan blimey, that doesn't sound good. Best of luck. I'm waiting for my installers to come back in a couple of days to wrap up the Solar & do the last bits of my ASHP, so I hope that I can get my stuff fixed up too.

@justinsb 

Like you I have a third party wireless room stat.  Heatmiser neo Air V2-M.

@morgan,

why don't you move the weather compensation curve down (the big zero) to lower the temperature?   That's what I'm doing as I've turned my thermostats right up so they are always calling for heat and the ASHP is always on.