Midea Heat Pump - Activating of cooling

[Exit]

Hi all is there anyone who knows how i can activate the cooling on an Midea air source  heatpump. i was able to set it to cooling but its also showing OFF. 

 

I have reduced the temperature for the thermostat and this does not change the status to ON. Please if you have any ideas let me know

[jack]

Welcome to BuildHub.

Are you sure the cooling isn't controlled by dry contacts (i.e., a separate set of contacts to those probably controlled by your thermostat for heating)? If so, you'll need a separate thermostat (or a switch if you're okay with manual operation) connected across the cooling contacts.

[ProDave]

I tried downloading the manual from their website but then it needs a password.  How stupid is that for the manufacturer to make the manual a download and then presumably need you to contact them for a password?

[mike2016]

no idea of your model but try this? 

[Radian]

This Midea ASHP manual Suggests it selects cooling mode automatically by the wired or wireless controller:

 

■ Pump operation and space heating and cooling According to the season, the unit(1) will switch to either heating or cooling mode according to the temperature detected by the standard controller (or optional wired controller (4)).

 

But elsewhere it also says:

 

● Remote shutdown and Remote cooling/heating is optional function.

● Choose this function by DIP switch SW4_1 (for 1-phase) or SW3_1 (for 3-phase) on PCB board. Factory default has no remote cooling/heating.

 

If we knew the model number it might help.

[ykhan16]

I have a Midea, model MHC-V12W/D2N8-B. Desperately looking for some way to take the edge of this heatwave so reviving this thread. Anyone able to assist?

[JohnMo]

Download the manual if you don't have it. Normally need volt free contacts making or breaking.  If you don't have fan coils or UFH, it will not help and it's not suitable for radiators.

[ykhan16]

No fan coils- UFH on the ground floor and vertical radiators on the first floor. I was hoping running the ASHP in cooling would give some marginal benefit. I spent a good few hours trying to find the manual online with no luck- think I did somehow find one on my phone the other day but it wouldnt open without a password for some reason. Tried emailing Midea for info and they replied with:

"Unfortunately this is something we are unable to advise on, your system would have to be designed for cooling, if this was just switched on it could cause damage to the heating system."

 

Basically they want me to go back to the installer (who no longer operate). *Sigh*

[jack]

14 hours ago, ykhan16 said:

I have a Midea, model MHC-V12W/D2N8-B. Desperately looking for some way to take the edge of this heatwave so reviving this thread. Anyone able to assist?

 

Engineering and service manuals are available here.

 

See this page for setting cooling mode.

 

Midea is correct that you want to be sure that your system is correctly set up for cooling.

[ykhan16]

50 minutes ago, jack said:

 

Engineering and service manuals are available here.

 

See this page for setting cooling mode.

 

Midea is correct that you want to be sure that your system is correctly set up for cooling.

 

Thanks for locating this Jack! Could you clarify what you mean by correctly set up? Is this in terms of what the system components are and how its been installed/piped/wired? [Dont know the ins and outs but we have ASHP, HWC and UFH/radiators for heating and looks like a pretty standard install]. Or did you mean the set up on the controller?

 

Dont want to mess up or break anything..

[JohnMo]

1 hour ago, ykhan16 said:

correctly set up

So do you have a buffer or volumiser? 

 

If so where are they located in the system with respect the diverter valve (for heating or DHW)?

 

UFH heating pump and mixer?

 

Thermostats?

 

 

[jack]

1 hour ago, ykhan16 said:

Is this in terms of what the system components are and how its been installed/piped/wired?

 

Yes, this. 

 

In addition to what @JohnMo says, I imagine your radiators won't do much for cooling, so should probably be turned off during summer (remember to turn them back on before the heating season!)

 

You'll probably need a thermstat for cooling. Most thermostats for heating applications are configured to close (i.e., switch on) when the sensed temperature is below the set point. For cooling you'll want the opposite. I think (but am not 100% sure) that some thermostats can do both. If so, there'll be three electrical terminals: common, NO (normally open) and NC (normally closed).

 

It's possible you can do something manual - i.e., no thermostatic control - by wiring a switch, or better yet a timer, across the cooling demand terminals.

 

Either way, hopefully whatever wiring was used for your current thermostat has at least one spare core so you can use that rather than running another wire.

 

I suggest you post answers to JohnMo's questions and go from there.  

[JohnMo]

In addition to what @jack says, some UFH controllers are configured to manage cooling, automatically or manually.

 

A normal thermostat set to 21 degs, if below 21 it call for the heat source to start, above 21 it tells it to stop. Cooling needs the opposite.

 

 

[Conor]

For cooling just set the thermostat way way up so it never turns off. make sure all of your zones are open, diverter valve in right position, select a sensible flow temp (e.g. 12c) and see how it goes. 

[jack]

33 minutes ago, Conor said:

For cooling just set the thermostat way way up so it never turns off. make sure all of your zones are open, diverter valve in right position, select a sensible flow temp (e.g. 12c) and see how it goes. 

 

This won't work in a set-up that has separate terminals for cool and heat demand (which is how mine works).

 

You could temporarily rewire the thermostat across the cool demand terminals summer and do what you say.

 

I don't know that I'd risk having the thermostat wired across both demand terminals. While I'm sure there's probably some sort of priority involved, simultaneously calling for heat and cooling feels like a bad idea!