Baxi DUO-TEC COMPACT - ADJUSTMENT AND SAFETY DEVICES; Boiler Safety Mechanisms; PUMP CAPACITY AND HEAD; Pump Performance Chart

7710400 (01-06/18) 18
INSTALLER Section (en)
16. ADJUSTMENT AND SAFETY DEVICES
The boiler has been designed in full compliance with European reference standards and in particular is equipped with the following:
• Limit thermostat
Thanks to a sensor placed on the CH ow line, this thermostat interrupts the ow of gas to the burner if the water in the primary
circuit overheats.
It is forbidden to disable this safety device
• NTC fumes sensor
This device is positioned on the fumes-water exchanger. The electronic board stops gas from owing to the burner in case of over
heating.
It is forbidden to disable this safety device
• Flame ionisation detector
The ame sensing electrode guarantees safety of operation in case of gas failure or incomplete ignition of the main burner. In
these conditions, the boiler blocks.
• Hydraulic pressure switch
This device allows the main burner to be ignited only if system pressure is higher than 0.5 bars.
• Pump post-circulation
The electronically-controlled pump post-circulation function lasts 3 minutes and is enabled, in the heating mode, if the ambient
thermostat causes the main burner to go out.
• Antifreeze device
The electronic boiler management system includes an "antifreeze" function for the heating and DHW systems which, when ow
temperature falls below 5° C, operates the burner until a ow temperature of 30° C is reached. This function is enabled when the
boiler is switched on, the gas supply is open and the system is correctly pressurised.
• Anti-block pump function
If no heat demand is received in the heating and/or DHW modes for 24 consecutive hours, the pump will automatically start and
operate for 10 seconds.
• Three-way valve anti-blockage function
If no heat demand is received for a period of 24 hours, the three-way valve performs a complete switching cycle.
• Hydraulic safety valve (heating circuit)
This device is set to 3 bar and is used for the heating circuit. Connect the safety valve to a drain trap. Do not use it to drain the
heating circuit.
• Heating pump pre-circulation
In case of a heat demand in the heating mode, the appliance can pre-circulate the pump before the burner is ignited. This pre-
circulation phase last from a few seconds to a few minutes, depending on the operating temperature and installation conditions.
17. PUMP CAPACITY/ HEAD
This is a high static head pump t for installation on any type of single or double-pipe heating systems. The automatic air valve
incorporated in the pump allows quick venting of the heating system.
KEY TO PUMP CHARTS - “SECTION” E
Q RATE OF FLOW
H HEAD
18. POSITIONING THE ELECTRODES
See the gure in "SECTION" F at the end of this manual.