I haven’t got a Daikin but I have been having some fun with MQTT on another thread. If anyone else can cover off the normal Daikin control stuff I’m happy to help fill in the MQTT and HA bits.

@majordennisbloodnok Thank you!

My biggest head scratcher right now is I have the below automation (and similar) setup for overnight hot water, but the Daikin unit completely ignores it and heats DHW to 50c whenever it wants.

---

alias: Daikin DHW - Start Off Peak Heating (50C)

mode: single

triggers:

  - at: "00:30:00"

    trigger: time

conditions:

  - condition: time

    weekday:

      - mon

      - tue

      - wed

      - thu

      - fri

      - sat

actions:

  - target:

      entity_id: climate.bridge0_dhw_dhw_setpoint

    data:

      hvac_mode: heat

    action: climate.set_hvac_mode

  - delay: "00:00:02"

  - target:

      entity_id: climate.bridge0_dhw_dhw_setpoint

    data:

      temperature: 52

    action: climate.set_temperature

  - data:

      name: Daikin DHW

      message: "Off-peak start: DHW ON, target 52°C"

      entity_id: climate.bridge0_dhw_dhw_setpoint

    action: logbook.log

So to clarify (and rephrase the problem into my own terms - bear of very little brain, here...), you're saying you can't find anywhere in the onboard controls of your heat pump where there's a schedule to heat your DHW and yet it's always staying at 50degC or reheating immediately it drops below that level. Is that correct? Or is it that your automation is trying to get the DHW to 52degC but the heat pump stops at a ceiling of 50degC?

@majordennisbloodnok That’s correct. I can’t find anywhere in the heat pump controls that should be preventing Home Assistant from scheduling a 52c heat of the DHW.

Interestingly, in the installer settings on the Indoor Unit, there is a screen that shows 50c as you go into the setup. But it is greyed out and can’t be changed. That leads me to believe there may be a hidden Daikin setting I’m not aware of!

@weoleyric, apologies for the delay in response.

Given your last post, I'm still not clear whether you're having trouble finding where the DHW max temperature can be changed or whether you're having trouble finding how to change ANY of the DHW settings/schedule - in both cases, within the Daikin in-house controller. As a result, I'm trying to get hold of a forum member who's familiar with their way around the settings of your in-house controller so we can burrow into the settings and see what's going on.

Once we're clearer about what your heat pump is actually configured to do within its own settings, that's when I'd like to look at Home Assistant and see if you can do what you want by manually changing settings in HA. That'll prove that the MQTT communication is working properly. Once we've done that, that's when we can look at the automation and see if anything needs to be changed. First step, though, is to ignore anything outside the Daikin settings so we can simplify the problem.

@weoleyric Oh Dear, I don’t think I am going to be of much help here as my DHW is handled totally separately using a Sunamp Thermino ePC 210 unit.

Nevertheless, my heat pump is the 8 kW version of the Daikin EDLA08 monobloc with the MMI controller. Main control has been placed in the hands of the Homely Smart Controller though. @majordennisbloodnok wondered if I may be able to help - but I doubt I’ll be of any use to you here. Have you accessed the MMI settings that the installer uses? By setting up at installer level by using the code 5678 rather than the usual user level, you will have access to far more parameters. As I say, I don’t use the DHW settings on the MMI but you should be able to shuffle through the options for water heating and find the adjustments there. This may mean going down four or five level of submenu so take a packed lunch with you! Do you have the installer’s manual as this will show the route to you - though as manuals go, it is not the best example of clarity I’m afraid! Regards and Good Luck, Toodles.

On the contrary, @toodles, that’s a lot of help. I’d never have known about the code for the installer’s menu. Thanks.