Hi all

I’m currently experimenting with my system. I have an Ecodan 11.2kW heat pump and two zones controlled using Mitsubishi wifi thermostats.

I’ve finally managed to get the pump to work using a combination of WC with a high(ish) curve (got some great run time and COP this morning) and room adaptation mode in the afternoon.

From some help of @Timbones we’ve monitored the system and have it down to a zoning issue. Essentially, when one zone is off, the radiators cannot emit enough heat to cool the system, so I get a load of cycling. When both zones are on, I get great COP and run time.

Both zones are set to the same temperatures at all times of the day. I’ve moved the stats into the same location to try and get them to act as one zone, but this doesn’t appear to be working as one of the stats seems to read a slightly different temperature. This in turn means that both zones switch off at slightly different times, leading to cycling. See the example below:

This is what happened with both zones on between 7:10 and 8:20:

Does anyone know a way of making both zones controllable via a single stat? i.e. the stat in zone 1 controls both zones…?

Thanks in advance

Presumably you just configure the FTC6 as a single zone, one remote wireless and wire the two zone valves to the same power output so they both open and close at the same time.

Most valves have a slave output so you can just run one off the other.

My two zones appear to work fine - no drop in COP.

Presumably it’s a combination of new emitters, fast flow rate and the 3-pipe 90l buffer - I think the buffer gets used more when one zone closes as what little flow it gets normally probably increases.

1 Like

Can Zone 2 be set to be controlled by the first wireless controller (RC1) instead of the second?
There looks to be a setting on the FTC for this, under “Initial settings”:

Hi, I tried that setting, but when you do that, you can only use each stat once. So then there would be no controller for zone 1…

I essentially need one stat to control both valves… I can set both zones to be zone 1, but I’m not entirely sure what that would do.

When I get home, I’ll try and get some photos of the FTC6 so you can see what I mean.

There is no buffer on my system as far as I am aware. It’s one of the preplumbed units from Mitsubishi.

I might need a bit more technical help with your suggestion…

Right here goes…

This is where you can select which sensor does which zone.

I can set both stats to zone 1, but I assume that would leave zone 2 open all the time…?

In the section you have highlighted above for the sensor setting I get this:

There is no option to select Room RC1. I assume this is because that sensor is already being used for zone 1 and hence you can’t use a single sensor to control 2 zones… having said that, does anyone know what would happen if I set both sensors to control zone 2 (from the first picture)???