Advanced TRV settings: Control type of valve
In Advanced Options of the TRV you can choose between three “control types” : 0 PID, 1 FLOAT, 3 ON/OFF.
They greatly change the behavior of the TRV.
Still very unclear - experience needed - What are you using?
At last edit I was 5 days into experimenting with the PID control type and collecting experience, so I will update this section more often.
0: PID
What is a PID?
Generally speaking a PID Controller is a mathematical calculation, that tries to calculate changes in the past into future changes and switches Heating accordingly. Normally you can change the PID parameters to adapt to your specific conditions (e.g. heat loss,heating power, heat preserved in the radiator once hot). Sadly the PID parameters are factory set and not accessible.
Additional info: What is an PID?
(my experience with PIDs comes from tinkering a PID to my espresso machine)
Pro:
Valves do open and close in 5%-steps.
- at the moment i am set at 18,5° C for a target temp of 20,5° (Reason behind probably the pre-programmed PID parameters, that are meant for a standard (asian?) room, that is loosing heat very fast (my thinking at the moment))
- once the TRV has decided to open to a position (lets say 50%) it seems to close only in steps of 5% but only every few minutes. This sometimes produces overheating (at least in my room).
- if windows open detection is running and for example a window open temp is set, that is way lower than usual comfort temp, then closing the window and going back to comfort temp (e.g. 18,5°->14°->18,5°) makes the valves open quite a bit → regardless of actual temp → overheating
1: FLOAT
Did not test this out yet myself - scarce information available
2: On/Off
Seems to work fine - Despite the name, this setting is more than on/off - Stepping is done in steps of 25%, not 5% with the PID setting - Probably the TRV has set valve position linked to temp difference between set and curren temp.
In case your TRV-Valve-combination does not let water through at 25% this control type won´t open more. I will just wait for hours It won´t open the valve any more, when there is no heat coming though. It will do so, when the current temp is much lower that the set temp.
@flixx (See his post) has lower temp invariances with this setting instead of PID
Only for better SEO
Tuya TS0601 - Moes HY368 TRV - Moes HY369RT, SHOJZJ 378RT, Silvercrest TVR01, Immax 07732B, Evolveo Heat M30 - Control type of valve, Best Practice