AS NZS 5263.1.2:2020 pdf free.Gas appliances Part 1.2: Gas fred water heaters for hot water supply and/ or central heating.
9 AS/NZS 5263.1.2:2020
2.7.108.3 Limit thermostats
The limit thermostat for a central heating boiler or the central heating function of a combination appliance shall conform as follows:
(a) The limit thermostat shall conform to the requirements of JEC 60730-2—9 for Type 1 devices.
(b) The maximum set point temperature shall be non-adjustable.
NOTE When the water temperature falls below the set point of the limit thermostat, the gas supply to the burner may be restored automatically.
2.7.108.4 Overheat cut-off devices and safety temperature limiters
An overheat cut-off device or safety temperature limiter for a central heating boiler or the central heating function of a combination appliance shall conform as follows:
(a) The overheat cut-off device or safety temperature limiter shall conform to the requirements of IEC 60 730-2—9 for Type 2 devices.
(b) Interruption of the link between the sensor and the device responding to its signal shall cause at least safety shutdown.
2.7.108.5 Sensors
Thermostats, limit thermostats, safety temperature limiters and overheat cut-off devices shall have independent sensors, except that for an electronic system, thermostats and limit thermostats may have the same sensor, provided that in the event of failure of the sensor the appliance continues to conform to Clause 5.101.7.
2.7.109 Expansion vessel and pressure gauge for central heating boilers
If a sealed system expansion vessel is incorporated in a central heating boiler or the central heating function of a combined appliance, then —
(a) the expansion vessel shall be located or protected in such a way that heat cannot damage the diaphragm; and
(b) the appliance shall be fitted with a pressure gauge indicatingthe water-side operating pressure.
2.8 Gas train
This Clause of AS/NZS 5263.0 applies, except as modified below.
2.8.5 Main burner automatic shut off valves
All gas to the main burner shall pass through at least two automatic shut off valves in series that may be in a single control body. One valve shall be actuated by the temperature control device and or by water flow, the other by the device specified in Clause 2.7.104 unless both devices control both valves.
2.9 Combustion air and flue systems
This Clause of AS/NZS 5263.0 applies, except as modified below.
2.9.5 Design of flue connection
The flue connection shall provide means to prevent partial or complete blockage of flueways caused by the fitting of a flue pipe.AS NZS 5263.1.2 pdf download.