42
COMMISSIONING
TO FILL AND TURN ON THE WATER HEATER
The power supply to the water heater must not be switched on until the water heater is filled with water
and a satisfactory megger reading is obtained.
•
Open all of the hot water tap(s) in the building (don’t forget the showers) and supply cock(s) and valve(s)
in the system.
•
Open the isolation valves fully on the cold and hot water branches to the water heater(s) installed in a
bank.
•
Open the cold water isolation valve on the cold water line to the water heater(s).
Air will be forced out of the taps.
•
Close each tap as water flows freely from it.
•
Check the pipe work for leaks.
•
Inspect for leaks at the temperature pressure relief valve connection to the water heater.
If a leak is detected, close the cold water isolation valve fully and relieve pressure from the water heater
by either operating the easing lever on the temperature pressure relief valve or opening a hot tap. Remove
the valve and all of its thread sealant from the threads of the valve. Reapply new thread sealant and refit
the valve. Refer to the procedure in
“Temperature Pressure Relief Valve”
on page 31.
•
Operate the easing lever on the temperature pressure relief valve to check the smooth operation of the
valve plunger and that water discharges freely from the drain line. It is very important the lever is raised
and lowered gently. The lever should move smoothly and without undue force.
If the lever cannot be moved or is jerky in its movement, then the valve has been damaged and must be
replaced.
•
Open the gas isolation valve fully.
•
Check the gas pipe work for leaks.
•
Switch on the electrical supply at the isolating switch to the water heater(s).
•
Check the pipe work again for leaks when the system has reached its working temperature.
Warning:
Upon completion of the installation and commissioning of the water heater, leave this guide with
the householder or a responsible officer.
DO NOT
leave this guide inside of the cover of the water heater, as
it may interfere with the safe operation of the water heater or ignite when the water heater is turned on.
Explain to the householder or a responsible officer the functions and operation of the water heater.
GAS INLET PRESSURE
IMPORTANT
– CHECK
the gas supply pressure at the inlet to the water heater with the water heater and all
other gas burning appliances in the premises operating (burners alight). The minimum gas supply pressure is:
Natural Gas
1.13 kPa
If this minimum cannot be achieved, it may indicate the meter or the gas line to the water heater is undersized.
It is important to ensure that an adequate gas supply pressure is available to the water heater when other gas
burning appliances, on the same gas supply, are operating.
