Commissioning - Rheem 874 Owner's Manual And Installation Instructions

All water heaters are tested and adjusted before dispatch from the factory, however further adjustments may
become necessary because of local conditions.
TO TURN ON THE WATER HEATER
Open all of the hot taps in the house (don‟t forget the shower).
Open the cold water isolation valve fully at the inlet to the water heater.
Air will be forced out of the taps.
Close each tap as water flows freely from it.
Check the pipe work for leaks.
Open the gas isolation valve fully.
Check the gas pipe work for leaks.
Plug in the water heater at the power outlet and switch on the electrical supply.
Turn on a controller, if one is fitted, by pressing the on / off button.
The light in the on / off button and the priority light (standard controller) or ACTIVE light (Deluxe
controller) will both glow.
Open a hot tap.
The water heater will operate automatically.
Check to ensure the flow from each connected hot tap is sufficient to operate the water heater.
The minimum operating flow rate for all models is 3.0 litres per minute.
The automatic water governor incorporated in the water heater is not adjustable.
To complete the installation, it is necessary to check the gas supply pressure at the inlet to the water heater
"Gas Inlet Pressure"
(refer to
"Burner Gas Pressure"
(refer to
Upon completion and testing of the installation, ensure the controller(s) is turned off (if fitted). Explain to the
householder or a responsible officer the functions and operation of the water heater and the controllers (if
fitted).
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.
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
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.

COMMISSIONING

below), the minimum test point pressure and the maximum test point pressure
on page 69).
1.13 kPa
67
LPG 2.75 kPa