Connecting heat enable to Mitsubishi Ecodan

[Scotland]

Hello,

I'm a long time lurker to the forum since before I started building my house, getting near the finish now I have a few questions on Ashp, especially Mitsubishi Ecodan if anyone has experience in them.

I'm looking at wiring the heat enable circuit from the heatmiser uh8 wiring centre to the heat pump, which was not installed when the company fitted the heat pump.

Just a bit stumped as to where the cables terminate. 

I had them wired into the demand control part of the control centre , specifically in4.

When turning the heat pump on the water circuit heats up to temperature once then shuts off and doesn't turn on again.

Thought I might have had the wires around the wrong way but doesn't seem to make a difference.

The question is do I have this terminated into the correct ports on the control centre?

A few pictures attached to try and show the wiring and diagram.

 

Sorry for picture rotation, don't know how to fix.

Any help is appreciated, 

Thank you.

[ProDave]

Are you sure "demand control input" is what you want?

 

I would have thought "room thermostat" was a more likely candidate, after all the heat demand from the UFH controller is like a global thermostat output.

 

I don't know enough about the Ecodan to know the answer to that.

 

You probably also have to change some settings to enable each of these inputs to work.

[Scotland]

Hi Dave,

 

Thanks for the quick response,

 

I'm a joiner to trade so not that familiar with central heating systems to be honest, i know electrics in general but not enough to decypher this.

 

I just thought demand control would be the most possible candidate as I was working on the basis of the call for heat putting a demand on the system to switch on,

 

So anyone with more experience than me on these matters, the advice is very much appreciated. 

 

Thank you.

[PeterW]

Which FTC or Ecodan have you got as that looks like one of the older connection units. 

[Scotland]

Hi peter,

 

I think it's the ftc 4.

[Scotland]

More info, on ashp and pre plumbed cylinder.

 

PUHZ - W112VA and EHPT30X - UKHCW

[PeterW]

EHPT30X is fitted with an FTC5. Are you sure that’s the model number as that’s a 2015 cylinder if that is the case ..??

 

The DIP switch settings on the main board control what the UFH call for heat will do - you need to use Room Stat 1, but you need to know what SW2 has been set to. 
 

Out of interest, where is the expansion vessel for the UVC itself and the main incoming cold supply ..??

 

 

 

[SuperJohnG]

Looks a nice tidy  pipework job! 

[LA3222]

Before reading any of the comments I drew same conclusion as @ProDave. It mentions dip switch settings? 

 

 

[Scotland]

Thanks for the comments,

 

I will check the model number / switch settings when I get back from work tonight and report back.

 

The main cold and expansion cylinder for that side are at the other side of the tank.

 

 

[ProDave]

I don't think much of the pipework coming out of the tundish..........

[Scotland]

That made me smile, ?

 

Yes it's an old picture, it has been installed now.

 

The plumbers were not bad at the copper plumbing but when it came to pipe lagging that was a lot less to be desired, ( a mess ),  newer pictures show the lagging in them. 

 

Did not want the embarrassment posting them on a public forum ?

 

Could have got them back to fix, but I would probably never have been happy with the fix either.

 

I will fix it myself eventually.

 

I did the bulk of the plumbing work myself and just got a company in just to do the pipework for the ashp install, i bought the unit myself and installed the outside unit.

 

Ufh, rainwater harvesting, hot & cold circuits, all associated drainage works including sewage treatment tank and point to point radiator pipework install using manifolds, all installed by myself.

 

Some of which I've learned a good lot from the people of this forum.

[SuperJohnG]

@Scotland the manfolds look good - can you share where you got them from? 

 

Also - assuming you're in Scotland...where did you source your Ecodan from?

[Scotland]

4 hours ago, SuperJohnG said:

@Scotland the manfolds look good - can you share where you got them from? 

 

Also - assuming you're in Scotland...where did you source your Ecodan from?

Hi John,

Manifolds are hep20 brass manifolds I think I got them from JTM plumbing 

https://www.jtmplumbing.co.uk/pipe-fittings-c433/hep2o-pipe-fittings-underfloor-heating-c999/hep2o-brass-manifolds-c661

If that's the ones you meant anyway.

 

As for the Ecodan it was bought last year from Secon Solar.

[Scotland]

@PeterW

 

Hi peter,

 

My mistake the control centre is an ftc 5 not 4 like I said.

 

A few extra pictures I took tonight.

 

[PeterW]

So using Room 1 thermo you need a normally closed call from the UFH to open on call for heat, or change SW2-1 to ON which will stop the heat pump on break of contact. 

[LA3222]

Signal Inputs: In1= Room Thermostat 1 Input (Refer to SW2-1 in DIP Switch Functions)

 

Dip Switch Functions: SW2-1 = Room thermostat1 input (IN1) logic change --> OFF is when "Zone1 operation stop at thermostat short", ON is when "Zone1 operation stop at thermostat open"

 

I may be wrong but this says to me that you need to use In1 and not In4. Then when the thermostat is shorted the heating demand will be off, when the thermostat goes open circuit the heating demand will be on?

 

I'm reading on the fly with this so there is a lot of info I've skipped and i may have missed something important.

[ProDave]

I would not over think it.  I would connect your heat demand to thermostat 1 input and try it.  If you find the ASHP turns on when the UFH is off and vice versa you will need to change DIP switch 2-1

[Scotland]

Thanks,

 

I didn't have much time to mess about with it tonight but I changed the cabling to in1 and tried it with the sw2-1 switch in both directions but didn't seem to work, I possibly had to give it more time so I'll try again tomorrow,

 

Could also be how I'm using the heat pump right now, I only get working on the house at weekends atm so just switch the heat pump on say Fri night or sat morning and run it on flow temperature of 25 which is the minimum I can set it too, takes the chill away which is fine right now.

 

Would this setup work with flow temperature or do I have to put it on room temperature or compensation curve modes,

 

Could also be because I have 2 heatmiser uh8's and 1 uh4 connected via wago wiring centre to the cylinder for call for heat.

 

2 of which are switched off right now as they control radiator circuits. I might try disconnecting this tomorrow and run call for heat wire direct from ufh heatmiser to the cylinder, for troubleshooting purposes.

[PeterW]

Don’t forget that for a DIP switch setting to be recognised the unit has to go through a full start up sequence from power off. 

[Scotland]

1 minute ago, PeterW said:

Don’t forget that for a DIP switch setting to be recognised the unit has to go through a full start up sequence from power off. 

That could be the answer then, I know I shouldn't have but just changed the switch when the machine was still on.

 

Thanks for the help everyone and I will report back tomorrow when I try it again.

[Scotland]

Finally making some progress with this now, (sw2-1 set to off) I switch on ufh wiring centre and heat pump turns off and doesn't turn back on again until I turn the wiring centre off again. 

So I take it I need to turn sw2 -1 to on.

 

The other problem seems to be the heatmiser uh8 wiring centre, when no stats are calling for heat the valve light and boiler light are still on, any ideas on what the problem could be.

 

But when the main switch is put on from scratch the boiler light and valve light don't turn on until a stat calls, then don't turn off again. Even when no call is sent.

 

Do all the actuators need wired in before it works properly as I have some left off right now.

[ProDave]

Solve the heatmiser issue before fiddling with the dip switches.

 

With all thermostats down you should have all the lights off except Power.

 

When you turn any thermostat up, it's zone light should come on as should the Heat and Valve light.

 

Turn that thermostat and the lights should go off again.

 

Which bit of that does not operate like that?

[Scotland]

When the fused spur to the wiring centre is first switched on it looks like this 

 

No stats calling for heat in above picture.

 

When stat is calls for heat the heat light and valve light as well as the zone light comes on, the way it should work.

 

Problem is when the stat is turned off, the heat & valve light are still lit.

Like the picture in the last post.

 

Where the problem might lie is have a look at the zones where the actuators are plugged in, they are completely out.

The zones without actuators are partially lit but not fully.

They look like the power light when calling for heat.

[ProDave]

It looks to me like several of the zone lights are light up a bit.  they should be completely unlit.  do you have a multimeter to measure the voltage coming out of the thermostats?  I suspect there is a problem.

 

What thermostats are they?