I have an Ecodan FTC-6 board that the previous occupants of our house thought was a great idea to add Hive to as the Zone controls and treated it like a combi boiler setup. I’ve since moved it to being just a simple on/off call for heat when HA detects temps dropping. Unfortunately Hive seems to fail a little too regularly for my liking - solid amber light - and knocks the entire heating system to off so looking to replace this with a couple of Shelly dry contact relays I have lying around.
Our current set up is the Hive receivers are wired with the 1 and 3 terminal connected to IN1 and IN6. As far as I can make out, the Hive receiver simply connects 1 and 3 together as a dry contact to make the system call for heat, and disconnects them when not calling for heat. My proposal is to use these Shelly 1 Plus relays instead of Hive and control them from Home Assistant. At the moment I’m setting Hive to 32ºC when heat is required and then 15º when it’s not so it shouldn’t be a massive difference using the relays instead.
@F1p (thank you again for your hardware) recommended Mitsubishi wireless stats for auto adaptation and while it’s definitely on the list, for now I just want stability with the heating.
I know @Rachel mentioned doing something similar here but with a newborn and not wanting to blow anything up during this part of winter I’m just looking for a bit of reassurance.
So my question is - replacing the Hive receiver with Shelly 1 Plus relays, I assume it’s a straight swap with O and I on the shelly being wired to the two terminals on the FTC board for IN1 and IN6?
I stopped using the Shelly approach. I was originally using it on the ‘network operator demand management contacts’, but I realised that this rather harsh in that it just immediately turns off the compressor without any run-down.
I ended up getting a Home Assistant set up as there’s an add-in hack to talk to MelCloud, so I now use that to modify the Ecodan setpoint rather than directly switch it on and off.
Ah, see at the moment the two Hive receivers are basically just going “CALL FOR HEAT NOW” or “DONT CALL FOR HEAT” so I’m thinking there’s really no difference in firing in the two Shelly’s for the two zones. Other than it being more stable. I’m just really paranoid about blowing up the board or (like you say) giving the compressor a hard time even though every bone in my body tells me it is dry contact and would work the same, I still want to be 100% sure.
Nah just got the FTC-6 board but no remote stats or controllers. The tank is also not Mitsubishi so the flow rates aren’t reading.
Think the company that installed it just wanted some sweet grant money and did the quickest dirtiest job (they refused to service it when I bought the house) with bits and bobs they had lying around. Couple that with previous occupants who were more DI Why!? I’ve had a fun year and a half fixing this back to somewhat “normal”. The call for heat trigger is the last thing on the list.
So what’s your thoughts? Basically the same as Hive receiver, having the Shelly dry contact, right?
I would the say that the Shelly’s will be the same as the Hive so probably no additiopnla harm there.
The other option is to control it over the CN105 link (there’s a thread on this somewhere) I assume that would allow you to put it in AutoAdapt mode, but I’m not sure where it would pick up the temperature from?
I was having a think - you could avoid the shelly by linking the contacts out.
(Or set hives to 35)
Then in Home Assistant using Server Control Mode + the Prohibits to enable/disable as required. The call for heat will always be there from the linked out contacts
This method can usually lead to cycling and hence why the mitsi stats are recommended for the long term
In theory I could feed it an avg downstairs and an avg upstairs temp but given it’s not a conventional install I have no idea if that will actually “take”. I’ll have a look and see if that thread can solve some of my immediate wants/needs- thanks!
Might give the Shelly’s a try for now and over test just to make sure it’s 100% a like for like. It’s not ideal by any stretch, but at least it might be stabler.
@F1p - that’s what we do just now (hive to max) but the issue is when hive decides it’s not playing ball it seems to completely shut zone 1 and zone 2 down and locks itself at 20° and needs factory reset. At the moment one receiver is cutting out completely and yeeting itself from my zigbee network about every 3 days, sometimes twice a day which is less than fun when it happens at 2am and the house becomes an igloo.
Mitsubishi stats are on the Christmas list for next year. I promise!
Have you tried switching it to Heating Flow and switch the prohibit off and then just set a flow temp? Not sure if this will work if the thermostat is dropping off intermittently. Requires a bit more manual management for thermal comfort.
Hold up… just realising what you’re saying and brain is engaging.
In theory I can completely do away with the Shelly’s and/or Hive by jumping the two terminals on IN1 and similarly on IN6. It means it’s permanently on BUT if the return temp == output temp the pump should shut off… right? That shouldn’t cause any issues?
In theory could do that but the flow thermostat is seemingly reporting a static 20° no matter what’s happening, and zone 1 & 2’s flow setpoint is unavailable so I’m thinking somethings not quite wired up properly on my unit. Or I’m misreading something!
In theory I can completely do away with the Shelly’s and/or Hive by jumping the two terminals on IN1 and similarly on IN6. It means it’s permanently on BUT if the return temp == output temp the pump should shut off… right?
Yeah, and you can manually control when it’s on/off if you enter Server Control Mode - which is the only way you can change the prohibits. Or you can use the schedule in your FTC controller to time on/off
In theory could do that but the flow thermostat is seemingly reporting a static 20° no matter what’s happening, and zone 1 & 2’s flow setpoint is unavailable so I’m thinking somethings not quite wired up properly on my unit. Or I’m misreading something!
Flow Thermostats require you to be in Heating Flow mode (otherwise the FTC won’t accept changes to the setpoint)
Sensors Zone 1/2 Flow Setpoint should update though
You can see Flow & Return temperature values with sensors “Heater Flow/Return”
You might see “25” On Zone 1/2 Flow/Return Temperature if you don’t have the optional zone kit fitted
So I’m thinking link the contacts between IN1’s 2 terminals (and same with IN6), then use server control to prohibit DHW when heating is called for except when DHW drops below 6°/my two scheduled times and flip it to DHW unprohibited but the zones prohibited, all via a home assistant schedule. Nice and easy actually now I think about it. How does it handle legionella though? Is it smart enough to just blast past server control or is that something I need to schedule via home assistant (prohibit zone 1 and zone 2 and setpoint somehow)? Or does it override server control cause it’s legionella? Or am I maybe overthinking it and just turn server control off during the legionella cycles…
That should effectively do what I want for the meantime though, function the same way Hive is supposed to, and I can get rid of Hive completely from the network until I buy some Mitsubishi wireless stats. No need for Shelly’s.
Legionella still runs it’s own schedule, regardless of the server control mode status.
You will need to decide how DHW is considered, leaving the prohibit off all the time is one option.
Update on this - Hive failed completely this morning at 00:15 for the downstairs UFH (Zone 2) meaning the house plummeted from 19.5º-20º all the way to 16º over night. We didn’t notice because upstairs was still running (Zone 1) so looking to fix this today.
For the moment (just for the like for like factor) I’m going to replace the IN1 & IN6 Hive controls with Shelly 1 Plus relays. Not ideal, but it shouldn’t be completely different to Hive’s function but definitely different to the stability.
Once I’m brave enough, and it’s not -1º outside, I’ll look into linking 1 & 6’s terminals and play with prohibits but I’m sure by the time I look at this again wireless stats might be on Santa’s list.
I’m so angry at Hive. They keep touting their product as amazing but it’s just either crap by default or rebadged hardware with nerfed firmware (look at the TRVs - they’re danfoss but most of the functionality has been completely stripped). Obvs I’m not connecting to their central servers, which I’m sure they’ll claim is causing the issue, and it probs shouldn’t be used with an ASHP set up (thanks previous residents), but how on earth do they think this is an acceptable product for the majority of the public.
Thanks to everyone for the help. I’ll keep this thread updated as/when I change things just for any lurkers.
As an aside, I control my UFU using HomeAssistant. I use a simplified weather compensation means that I gradually raise the desired temperature over several hours so the UFH comes on at a time where I estimate it has enough time to reach the desired temperature. It is a bit rough and ready but works pretty well. Today, outside temp low, house cools more, starting temperature lower, so UFH comes on earlier.
I’ve got a 4 Relay ESP8266 board (gone off Shelly’s - too many pictures of burnt out relays). I wrote a script for it years ago but if I did it now I’d use ESPHome; ‘ain’t broke, don’t fix’.
Thanks, I’m now terrified . Nah I saw the burnt out pics too but given I’m at home 90% of the time I figured it was an acceptable risk behind a 13A fuse with temp sensor in that cupboard to detect anomalous spikes.
Out of curiosity @F1p / anyone else that has one - how do you control your Ecodan via home assistant using the Mitsubishi wireless stats? All I need it to do is power on zone 2 and zone 1 when it’s cold and off when it’s not in use, is that possible over the CN105 bridge?
As @Tango130 says, change the climate thermostat via Home Assistant with automations
It filters setpoint changes through automatically to the wireless stats after a minute or two. It’s all synced together, so changes either in home assistant or with the physical buttons on a stat will be displayed on the other after a short time.
It is effectively moving what is already possible within the controller schedules, but into home assistant and this is due to limitation in the controller with in how many adjustments that can be made in that schedule
. Nah I saw the burnt out pics too but given I’m at home 90% of the time I figured it was an acceptable risk behind a 13A fuse with temp sensor in that cupboard to detect anomalous spikes.