Thermal desinfection hot water

[BenPru]

Ideas for Thermal desinfection

• Allow to set a "thermal desinfection temperature" (e.g. default 60 C°)
• Add a sensor date "last thermal desinfection". Means a date stamp the hot water temperature was over "thermal desinfection temperature".
• Add a "Start thermal desinfection" "button" (e.g. automation, script or ...)
• Start thermal desinfection only if the "sun shines" or the outdoor temperature is over x?

[tetsuo55]

I'm not sure if the 4 tasks cover my needs yet.

I have the water temperature set to 53 to minimize risk.
Once a week the thermal disinfection runs, but it uses the electric element to go all the way from 53 to 60.

I want the heat pump itself to heat the water to as close to 60 as possible before the electric element is enabled

(Any temperature above 57 will cause an error and abort so we will have to inch closer and closer in several stages,doing this manually i can reach 58 with the remaining heat)

[pluskal]

@tetsuo55 have you looked into the installer menu in case these limits (to raise the error) are configurable?

[tetsuo55]

@tetsuo55 have you looked into the installer menu in case these limits (to raise the error) are configurable?

I have and they are not, it's a built in safety measure that can't be changed in any menu, well you could lower it further but that's counter productive

[pluskal]

If you are interested. We can elaborate on that.

I have checked on my unit that the maximal temperature for hot water is 65C and I think that I am able to disable the 2nd source. The firmware language on my machine is in Czech and the translation is at least "fuzzy".

[tetsuo55]

Yeah i have the same limit but the device sets 67c as temperature above a certain value and then it just throws the error

[rhammen]

Target TDI temperature seems to be stored in:
Number: 47 Name: ID_Einst_LGST_akt Type: Unknown Value: 610

value = (set temperature) * 10. So this example, TDI temperature = 61.0

[BenPru]

See pre-release 2022.12.15

Added number parameters:

• domestic_water_thermal_desinfection_target (parameters.ID_Einst_LGST_akt) with attribute LAST_THERMAL_DESINFECTION timestamp.

[kbabioch]

I'm wondering what the current status for this is?

It is my understanding that thermal desinfection cannot be done with the heat pump itself. Is this correct, or not?

At least, when I start thermal desinfection manually (by choosing the current day of the week in the menu on the controller) the electric heating element as secondary heat source kicks in.

That's fine, but I would like to have more control over it, e.g. I want to start it "on demand" and not by setting up days of the week, because you cannot do it twice a day and it will kick in at 0 o'clock on that particular day when you keep it enabled.

My use case is to heat up the water as much as possible when I have a lot of PV excess power (in the summer). Unfortunately I can only do this manually currently.

[AJediIAm]

I'm wondering what the current status for this is?

It is my understanding that thermal desinfection cannot be done with the heat pump itself. Is this correct, or not?

At least, when I start thermal desinfection manually (by choosing the current day of the week in the menu on the controller) the electric heating element as secondary heat source kicks in.

That's fine, but I would like to have more control over it, e.g. I want to start it "on demand" and not by setting up days of the week, because you cannot do it twice a day and it will kick in at 0 o'clock on that particular day when you keep it enabled.

My use case is to heat up the water as much as possible when I have a lot of PV excess power (in the summer). Unfortunately I can only do this manually currently.

I have been reading up on how thermal disinfection works on my Alpha Innotec heatpump. What I understand is that it is only needed if the water temperature is below 55C (sources vary between 50C and 60C). To properly disinfect the system, the water temperature needs to be above the thermal disinfection temperatuur for some time. Again, sources vary on the temperature and time. 55C for 2 hours seems to be on the safe side.

My heatpump was setup with a hot water temperature of 58C without thermal disinfection by my installer and I trust they meet all health and safety criteria.

This leads me to conclude that the second heat source is not needed for thermal disinfection. Temporarily changing the water temperature seems fine as long as the thermal disinfection temperatuur is reached for long enough. Since the heatpump heats the water up until the specified temperatuur after which it immediately begins to cool down, the temperature needs to be set a few degrees higher than the minimal thermal disinfection temperatuur to ensure the thermal disinfection temperatuur is exceeded for an hour or 2.

The sensor which tracks the last time the thermal disinfection temperatuur was reached is very useful. The script and further automations on when to start the thermal disinfection process are best left up to the user to automate. An example or 2 in the documentation might be nice, but I don't think the code should be part of the integration.

[kbabioch]

I have been reading up on how thermal disinfection works on my Alpha Innotec heatpump. What I understand is that it is only needed if the water temperature is below 55C (sources vary between 50C and 60C). To properly disinfect the system, the water temperature needs to be above the thermal disinfection temperatuur for some time. Again, sources vary on the temperature and time. 55C for 2 hours seems to be on the safe side.

Well, that is the theory of it, unrelated to Alpha Innotec. As you state there is some room for interpretation about the exact values and timing, but in general it sounds about right as far as I can tell.

My heatpump was setup with a hot water temperature of 58C without thermal disinfection by my installer and I trust they meet all health and safety criteria.

That sounds way to high for me personally - at least when you have energy saving in mind. Some people go down as low as 40° and only heat it up every now and then and/or have enough turn around in the tank.

But once again: This is the theory about "thermal desinfection", not the technical implementation within Luxtronik.

This leads me to conclude that the second heat source is not needed for thermal disinfection.

That's wrong :-). My use-case is to enable thermal desinfection whenever I have enough excess energy from my photovoltaic system, so that I can heat up the water - ideally without any mechanical stress to the compressor. For that I need to have control over the secondary heat source.

The sensor which tracks the last time the thermal disinfection temperatuur was reached is very useful. The script and further automations on when to start the thermal disinfection process are best left up to the user to automate. An example or 2 in the documentation might be nice, but I don't think the code should be part of the integration.

What sensors are there already? Is there any way to start thermal desinfection by usage of the secondary heat element?

[AJediIAm]

What I mean to say is that the a heatpump should be set up with the proper thermal disinfection configurations.
If a user wants to further optimize the power use of the thermal disinfection (at one's own risk), the two sensors "thermal disinfection temperatuur" and
"last thermal disinfection" are everything one needs to automate it.

It's not possible to change the build in thermal disinfection time using the second heat source. The existing controls need to be used to change the temperature.

[kbabioch]

It's not possible to change the build in thermal disinfection time using the second heat source. The existing controls need to be used to change the temperature.

What I'm essentially looking for is a way to use the secondary heat source to heat up my water without stressing the compressor. Personally, I don't care about the thermal desinfection aspect, but so far the only way to enable / trigger the secondary heat source was to enable the thermal desinfection for that particular day.

If there is a way to enable the secondary heat source any other way, I'm happy to learn about it, as the only thing that I want to do is to "store" some energy during the sunny hours of the day, to have it available in the evening without having the heat pump to kick in once the sun has set and everyone is taking a shower.