Central heating overshoots ... how to fix it?

Hi,
I have a central heating (gas heater with hot water distribution to radiators around the house).

I have solenoid valves on the collector outputs (to the radiators) that are controlled by HA. So HA can switch on/off each individual radiator by opening and closing off the waterflow to it …

In each room I have a temp sensor, so I can program a thermostat for each room (reading the temp from the sensor and opening the solenoid valve for this specific radiator/room)

all is well … but here is the problem :
in my home-office there are 2 radiators, and each time they are activated (because the temp goes under the threshold value) the temp in the room overshoots massively because the radiators keep giving heat well after the system shuts the solenoids off (because it’s warm enough).

I’ve been thinking how to solve this … but I can’t seem to find a solution …

Anyone has any experience with this kind of problem ?

Thanks a million !

This could be your solution, if you understand of are ready to learn about PID.

GitHub - ScratMan/HASmartThermostat: Smart Thermostat with PID controller for HomeAssistant

2 Likes

This may work
Use only one radiator to controle the temperature and the other one as backup like
Example
Rad1 open at 19 and close at 20 degrees

Rad2 open at 18,5 and close at 19,5
And if rad 1 is open for x minutes and temp is still below x then open rad2 also