Mitsubishi Ecodan - Can you run it backwards?

[Matt60]

I am having a highly recommended local firm provide a quote for the full plumbing system including ASHP. Their preferred unit is a Mitsubishi Ecodan system as they say they are very reliable and the after service is miles better than Daikin etc.

 

When I asked for the quote, I told them that I wanted a system that I can run backwards in the summer from the PV in order to cool the house via slab cooling. This firm have spoken to Mitsubishi about it who where not keen on the idea at all and essentially said it couldn't.

 

This is the 4th firm I have spoken to about a system and none of them have ever heard about running a ASHP backwards let alone have done it. 

 

My question is simply; Has anyone got any experience of running an Ecodan backwards or another ASHP, either way, could you provide details of make and model and how you did it?

 

Thanks in advance.

[PeterW]

Yes you can as long as it’s not on RHI as they disable the ability for the unit to do cooling. 
 

You also need to make sure you add isolator valves so you don’t try and cool the DHW tank in error. 

[SteamyTea]

https://forum.buildhub.org.uk/topic/14636-ecodan-cooling/

 

Running backwards is not really the right term to use.

This caused a lot of confusion with heat pumps.

Edited May 24, 2021 by SteamyTea

[Carrerahill]

5 minutes ago, Matt60 said:

I am having a highly recommended local firm provide a quote for the full plumbing system including ASHP. Their preferred unit is a Mitsubishi Ecodan system as they say they are very reliable and the after service is miles better than Daikin etc.

 

When I asked for the quote, I told them that I wanted a system that I can run backwards in the summer from the PV in order to cool the house via slab cooling. This firm have spoken to Mitsubishi about it who where not keen on the idea at all and essentially said it couldn't.

 

This is the 4th firm I have spoken to about a system and none of them have ever heard about running a ASHP backwards let alone have done it. 

 

My question is simply; Has anyone got any experience of running an Ecodan backwards or another ASHP, either way, could you provide details of make and model and how you did it?

 

Thanks in advance.

I think the phraseology you are using is what is confusing them, all ASHP's I have ever used have had a cooling mode, yes in theory the cycle is in reverse or as you say "running backwards" but I think that is confusing them. Just confirm it has cooling mode or better, get onto the Mitzi site and download the datasheet to confirm.

 

Installers are good at installing stuff, they tend, not always, but do tend, to be a bit clueless and lacking in any care of actual use or functionality like a user like you is discussing.

[Matt60]

That's excellent - thanks for all your replies, much appreciated.

[LA3222]

Yarp, they do have a cooling mode. It is a dip switch  on the FT5 controller and jobs a good en?