Connecting heat enable to Mitsubishi Ecodan

[Scotland]

Heatmiser neostat v2.

Probably have a multimeter lying about somewhere.

 

Bit weird though that the ones with actuators are off but ones without are on, 

 

Tomorrow I'll temp fit all the actuators and see what difference that makes.

If any ?

[ProDave]

I haven't looked them up but I bet they are solid state not relay output and there is just enough leakage on an output that is "off" to upset the controller.

 

connect ALL the actuators even if not physically in place and I bet that problem will go away.

[Scotland]

@ProDave

 

Connecting in all the actuators did the trick, all working as it should now.

 

Thanks.

 

Just the heat pump to sort out now, will have a look at it again at the weekend when I have more time.

[Turpo]

@Scotland

have you had any luck with this?

I have relatively new ecodan installed with wireless thermostat and it works fine. 
I just installed UH8 for my UFH and when I wire heat demand from it to pump main panel it doesn’t fire up.
Current thermostat receiver is witted to IN1 so it should be as easy as taking two wires out and connecting two form UH8. Should be 5min job but….. it doesn’t work!!! 
 

 

[Mark1306]

@Scotland I am in same rabbit hole with UH8, NeoStat wireless stats and FTC6 on my cylinder.

 

System worked fine for months but has been chewing through energy recently, irrespective of outside temp.

 

My installer disappeared and there is no Mitsubishi authorised agent close.

 

Remote help from other installers hasn’t changed the situation.

 

There was never any connection from the heat enable on UH8 to FTC6. ASHP is running almost all the time.

 

How should this have been wired and why did it ever work?

[Omi]

Just adding to this as I've had the exact same question (UH8 + ecodan FTC6) and managed to figure out the answer.

 

My installer had left the ASHP configured with SW 2-1 set to ON but nothing connected to IN1 (TBI.1 7-8) with the plan being that I'd connect the demand from the UH8 once I had all of that wired up. Obviously, the heating worked just fine even without a thermostat being connected to IN1 so I wondered why anything would change once the UH8 demand was actually connected up to the FTC6 IN1.

 

A closer look at the FTC6 manual provides the answer. Without any external thermostat input, the system operates according to "Option C":

 

 

In my case, the remote controller was set to "Auto Adaptation" mode where it uses the thermistor built into the remote contoller itself to provide the "thermostat" function for the FTC - ignoring anything connected to IN1.

 

To actually make use of the demand signal from the UH8, the controller mode must be set to either "Flow temp." or "Compensation Curve" according to the manual (Option D):

 

 

In my case, I've opted to go for the "compensation curve" option and can see the ASHP turning ON/OFF in accordance with the demand signal from the UH8.

 

I think it's essential that the operating mode of the FTC remote controller is changed from "auto adaptation" as soon as the UH8 and actuators are installed since I can envision a scenario where the ASHP eats up energy without actually providing any heating. This might happen if the remote controller is set to a higher temperature than the stats? The stats will shut off the UFH circuits once they reach target temperature but the remote controller (in auto adaptation mode) will keep running the ASHP trying to reach the higher temperature set in the remote controller. But of course this will never be achieved since the stats have already shut off the circuits ....  

 

NOTE: The FTC6 manual states that the ON/OFF cycle time of the thermostat must be 10 minutes or more to prevent damage to the compressor; however, by default the neoStat v2/Polypipe UFHSMARTW "delay start" function is set to 0 minutes (immediate). To remove any possibility of short cycling, I've increased this to 12 minute on my stats.

[connick159]

On 01/10/2023 at 23:17, Omi said:

Just adding to this as I've had the exact same question (UH8 + ecodan FTC6) and managed to figure out the answer.

 

My installer had left the ASHP configured with SW 2-1 set to ON but nothing connected to IN1 (TBI.1 7-8) with the plan being that I'd connect the demand from the UH8 once I had all of that wired up. Obviously, the heating worked just fine even without a thermostat being connected to IN1 so I wondered why anything would change once the UH8 demand was actually connected up to the FTC6 IN1.

 

A closer look at the FTC6 manual provides the answer. Without any external thermostat input, the system operates according to "Option C":

 

 

In my case, the remote controller was set to "Auto Adaptation" mode where it uses the thermistor built into the remote contoller itself to provide the "thermostat" function for the FTC - ignoring anything connected to IN1.

 

To actually make use of the demand signal from the UH8, the controller mode must be set to either "Flow temp." or "Compensation Curve" according to the manual (Option D):

 

 

In my case, I've opted to go for the "compensation curve" option and can see the ASHP turning ON/OFF in accordance with the demand signal from the UH8.

 

I think it's essential that the operating mode of the FTC remote controller is changed from "auto adaptation" as soon as the UH8 and actuators are installed since I can envision a scenario where the ASHP eats up energy without actually providing any heating. This might happen if the remote controller is set to a higher temperature than the stats? The stats will shut off the UFH circuits once they reach target temperature but the remote controller (in auto adaptation mode) will keep running the ASHP trying to reach the higher temperature set in the remote controller. But of course this will never be achieved since the stats have already shut off the circuits ....  

 

NOTE: The FTC6 manual states that the ON/OFF cycle time of the thermostat must be 10 minutes or more to prevent damage to the compressor; however, by default the neoStat v2/Polypipe UFHSMARTW "delay start" function is set to 0 minutes (immediate). To remove any possibility of short cycling, I've increased this to 12 minute on my stats.

Thanks for this post. Its really helped!
What if you had 2 UH8 wiring centres, one in front of the house and another for a new extension at the back of the house. Each with their own manifolds. How could you connect up the 2nd UH8 back to the FTC6?