Hot Water Tanks



7.6.1.8.(1)

Every water pipe that supplies a hot water tank, pressure vessel, plumbing appliance or water using device shall be provided with a shut-off valve located close to the tank, pressure vessel, plumbing appliance or water using device.


7.6.3.2.(2)

No water system between the point of connections with the water service pipe or the water meter and the first branch that supplies a water heater, shall be less than 3/4"size.



7.2.10.11.(1)

Temperature relief, pressure relief, combined temperature and pressure relief and vacuum relief valves shall conform to CAN1-4.4, "temperature, Pressure, Temperature and Pressure Relief Valves and Vacuum Relief Valves", or ANSI Z21.22, "Relie Valves and Automatic Gas Shut-off Devices for Hot Water Supply Systems".



7.6.1.12 Relief Valves

  1. Every pressure vessel that is part of a plumbing system or connected to a plumbing system shall be equipped with a pressure relief valve designed to open when the water pressure in the tank reaches the rated working pressure of the tank, and so located that the pressure in the tank shall not exceed 1100 kPa (160 psi) or 1/2" the maximum test pressure sustained by the tank whichever is the lesser.


  1. Every hot water tank of a storage-type service water heater shall be equipped with
  1. temperature relief valve with a temperature sensing element located within the top 150 mm of the tank and designed to open and discharge sufficient water from the tank to keep the temperature of the water in the tank from exceeding 99oC (212o F) under all operating conditions, or
  2. a device that

i) is designed to shut off the supply of electricity or fuel to the heater,

ii) is not connected to and operated independently of the water in the tank, and

iii) is located and maintained on or within the top 150 mm of the tank so that the maximum temperature of the water in the tank shall not exceed 99oC (212o F) under all operating conditions.

  1. Every tank equipped as specified in Clause 7.6.1.12.(2)(b) shall bear the information in a clearly visible location that it is so equipped.
  2. A pressure relief valve and temperature relief valve may be combined where Sentences (1) and (2) are complied with.




  1. Every indirect service water heater shall be equipped with

a) a pressure relief valve, and

b) a temperature relief valve on every storage tank that forms part of the system.

  1. A temperature relief, pressure relief, or a combined temperature and pressure relief valve which is installed on a hot water tank shall have a pipe that

a) has a size at least equal to the size of the outlet of the valve,

b) is rigid, slopes downward from the valve, and

i)

terminates with an indirect connection above a floor drain, sump or other      safe location, with an air break of not more than 300 mm, or

ii)

terminates at a distance not less than 150 mm and not more than 300 from a floor and discharges vertically down,

c) has no thread at its outlet, and

d) is capable of operating at a temperature of not less than  99oC (212o F). (See Appendix A.)




  1. The temperature relief valve required in Clause 7.6.1.12(5)(b) shall have a temperature sensing element located within the top 150 mm of the tank and be designed to open and discharge sufficient water to keep the temperature of the tank from exceeding  99oC (212o F) under all operating conditions.
  2. No shut-off valve shall be installed on the pipe between any tank and the relief valves or on the discharge lines from such relief valves.

Home