Central heating boiler controller TECH ST-81 zPID with exhaust gases temperature sensor

Central heating boiler controller ST-81 zPID is suitable for the purpose of operating manual solid fuel fired boilers in a simple central heating installation. Performed control functions of the controller are central heating pump, domestic hot water pump and blower fan operation. Central heating controller enables you to select from among four pump modes: central heating pump, hot water tank priority, parallel pumps, summer mode.

ST-81 zPID controller is using the zPID control algorithm where blower fan is calculated based on the measured boiler temperature and the temperature of the exhaust gases through the exhaust temperature sensor (included).

In contrast to conventional controllers zPID controller is continuously using the fan controlling the blower power based on the difference of boiler temperature and flue exhaust gases temperature adequately to a temperature setpoint. As result, violent blower fan operation at full speed is avoided (turning fan off and work again) in the case of temperature setpoint value deviations (which stops unnecessary heat losses into the chimney) without overshoot. Estimated zPID savings vary from a few to several percents of fuel and lower air pollution emissions to the atmosphere.

Stability and precision chart with zPID algorithm and without

Boiler controller with zPID

Boiler controller without zPID

Boiler controller housing is designed for an installation on the boiler horizontal casing.

Functions performed by the controller TECH ST-81 zPID

• Automatic operation of the boiler blower
• Central heating and domestic hot water pump control

Equipment kit controller TECH ST-81 zPID:

• LCD display with backlight
• Temperature sensor C.O
• Temperature sensor C.W.U
• Exhaust temperature sensor
• Additional (thermal) temperature protection
• Casing made of high-quality materials resistant to high and low temperatures
• The possibility of installation in OM-01 boiler casing