Run "luxtronik_0_00_circulation_pump_heating" and "luxtronik_0_00_pump_flow" manually

[Officer-on-duty]

To build a DIY cooling system, I would like to run these pumps manually. This is just to run an external heat exchanger with the ground source (passive cooling). I have already finished the pipe installation, but I am unable to run the pumps manually.

[rhammen]

Thanks for the detailed report! A couple of things worth clarifying and two possible paths forward.

First, circulation_pump_heating and pump_flow are read-only status sensors (ID_WEB_HUPout / ID_WEB_VBOout) — they report whether the heating circulation pump (HUP) and the heat-source/brine pump (VBO) are currently running, but they can't be written to directly. So "activating" them isn't possible as such; what you actually need is a way to make the heat pump itself run the VBO for your exchanger loop.

Option 1 — use the heat pump's own automatic passive cooling

This integration already exposes the heat pump's built-in passive cooling control:

• switch.<device>_cooling — Automatic/Off
• Cooling target temperature per mixing circuit (MK1/MK2/MK3)
• Cooling outdoor-temperature threshold, start/stop delay

When enabled, the heat pump's own logic decides when to run VBO/HUP for cooling — no manual pump control needed. The catch: this only works if your exchanger is plumbed into one of the heat pump's existing MK circuits, and that circuit's type is set to "Cooling" or "Heating+Cooling". That type setting is an installer-level parameter (ID_Einst_MK1/2/3Typ_akt) that has to be changed on the heat pump's own control panel — it isn't exposed as a writable entity in this integration.

So: is your external heat exchanger plumbed into one of your existing MK circuits, or is it a standalone loop tapped directly off the ground/brine line? If it's an MK circuit, setting that circuit's type to cooling on the heat pump panel and then flipping switch.cooling here is the cleanest solution — it gets you the real automatic passive cooling logic (outdoor temp threshold, delays, dew-point handling if your unit has that sensor) instead of a manual bypass.

Option 2 — experimental: try the VBO pump-control parameters directly

If your loop is a standalone tap (not an MK circuit) and option 1 doesn't apply, there are two undocumented parameters that look promising by name, though neither this integration nor the upstream python-luxtronik library has confirmed what they actually do:

• ID_Einst_P155_PumpVBOCtrl (parameter index 1039)
• ID_Einst_P155_PumpVBO_RPM_C (parameter index 1040)

The naming suggests a VBO pump control-mode setting and a target-speed/RPM constant, but this is a guess — nobody has verified it on real hardware.

If you're willing to experiment carefully:

1. Download the integration's diagnostics (Settings → Devices & Services → Luxtronik → ⋮ → Download diagnostics) and note the current values at indices 1039 and 1040 before changing anything, so you can restore them.
2. Try reading/writing via the luxtronik2.write service, e.g.:

   service: luxtronik2.write
   data:
     parameter: "ID_Einst_P155_PumpVBOCtrl"
     value: 1

   and separately try ID_Einst_P155_PumpVBO_RPM_C with a plausible RPM-ish value.
3. Change one parameter at a time, watch pump_flow / operating hours / any error/switch-off reason sensors for a reaction, and revert immediately if you see anything unexpected (short-cycling, error codes, etc.).

⚠️ These are unverified, undocumented parameters on hardware that also runs your heating and domestic hot water — there's a real risk of unintended behavior. Please only do this if you're comfortable experimenting on your own unit, and report back what you find (current values, what changing them did, if anything) — that would help confirm or rule out this lead for others hitting the same request.

[Officer-on-duty]

Ok thank you verry much! We are here:
Usually, the heat pump heats the underfloor heating and there is no NOVELAN KSE 192 or similar.
Now, the idea is:
Run the HUP and the VBO without the compressor.
The bypass in the underfloor heating circuit will lower the temperature as it loops through the heat exchanger.
So, the heat pump [compressor] is not necessary—I just have to run those two pumps, HUP and VBO.
The picture will show the details :-)

[rhammen]

Thanks for the picture and the extra detail — that makes the goal much clearer. Since there's no KSE 192 (or similar) installed, this isn't something the heat pump's own "cooling" logic will handle (that only applies to a properly configured cooling-capable mixing circuit), so Option 1 from my last comment doesn't apply here. This is really about manually forcing HUP + VBO to run together with the compressor off — good news is at least the HUP half is already solvable with entities this integration exposes.

Turning HUP on/off manually

This integration already has a "venting" feature that does exactly this for the heating circulation pump. Three entities are involved:

• number.<device>_pump_vent_timer_h — how many hours the vent run should last
• switch.<device>_pump_vent_hup — selects HUP as the pump to run
• switch.<device>_pump_vent_active — starts the run

To turn HUP on:

1. Set pump_vent_timer_h to however long you want it to run (e.g. 1 hour) — just set the value on the number entity, there's no separate "confirm" step, it writes immediately.
2. Turn pump_vent_hup on.
3. Turn pump_vent_active on — do this within a few seconds of step 2, the heat pump seems to expect them close together or it won't start.

HUP should then run for the configured duration. You can confirm it's actually running via binary_sensor.<device>_circulation_pump_heating. To stop it early, turn pump_vent_active off again (that should immediately end the run regardless of the timer).

One note in case it saves you some confusion: this is specifically the heating-circuit HUP. There was a report in #322 of these switches "not working," which turned out to be someone trying to use them for the domestic-hot-water circulation pump instead — a different pump these switches don't control (that's the separate, still-open #310). Since your bypass is on the heating circuit, you're using them for the right pump.

Does VBO come along for the ride?

That's the open question. Could you trigger a HUP vent run as above and watch binary_sensor.<device>_pump_flow (this is the VBO run-status sensor) while it's active? If VBO switches on at the same time as HUP, this whole thing is already solved with entities that exist today. If VBO stays off, we'll need a separate way to force it — I have a couple of unverified parameter leads for that, but let's confirm this first since it's the simplest possible outcome.

[Officer-on-duty]

Thanks again for looking into this.
I’ve actually tried this already. Unfortunately, the "_pump_flow" (Geothermal) remains off.
Moreover, "_pump_vent_hup" is related to the venting program. This means that when it's active, the pump runs for 5 minutes, pauses for 5 minutes, and then runs again for another 5 minutes....
So unfortunately, that won't work for our goal.