Manual Operation - TECH ST-21D5 User Manual

Operation of the controller
Preview of sensor temperatures is changed by pressing PLUS (temp. of
water in water heater: T1) and MINUS buttons (temp. of supply water
in the boiler: T2). By pressing MENU button the controller will display
the user's menu. Press PLUS or MINUS buttons to navigate in the
menu. Selection of the highlighted function or acceptance of a change in
settings is confirmed by pressing MENU button. Use EXIT button to
cancel the change or exit the menu. By pressing and holding the EXIT
button for 5s in the main screen the standby mode is activated and the
pump power supply is shut off. .
The following controller functions are available in the main MENU:

1. Manual operation

This function allows to start the pump manually (e.g. to check if it
functional). After selection of A1 function the pump can be turned on (by
pressing PLUS button) or off (by pressing MINUS button).
2. Pump turn-on delta
The option is used to set the difference in temperatures (Δ) between the
boiler and the tank (∆ = T1-T2) which, when reached, will cause the
pump to start, provided that the temperature exceeds the preset
activation threshold temperature.
3. Turn-on threshold temperature
This function is used to set a temperature which, when reached, will
cause the pump to start (so-called turn-on threshold temperature),
provided that the pump turn-on delta has been reached.
A1
A2
A3