Specifications

TM016 Rheem Gas Permanent Pilot Service Instructions

D.O.I: 01/2006

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Mixed or crossed plumbing connections

If an automatic dishwasher, washing machine, flick mixer tap, tempering valve or

thermostatic mixing valve is installed there is always the possibility that the cold water

could mix with the hot water through a faulty or incorrectly installed valve. This is referred

to as a crossed connection. The complaints of insufficient hot water, water too cold or

excessive discharge from the T&PR valve may be attributed to a cross connection. The

method of checking for a cross connection is:

1. Turn off the stopcock on the cold water supply to the water heater.

2. Open a hot tap. If water flow is persistent and cold, a cross connection exists.

Discoloured water

1. This may be the result of discoloured water entering from the cold water mains. Check

if the cold water is also discoloured.

2. Brown coloured water will generally indicate that the anode has been depleted or the

water heater is near the end of its useful life.

3. Milky coloured water is generally air in suspension and will disperse of its own accord.

In very hard water areas where anode gassing occurs, milky water may be evident.

The use of a blue anode should overcome this problem.

Fluing Principals

One of the major problems associated with all gas burning water heaters is poor fluing.

Many installers are unaware of the principals involved with balanced flue terminals or the

pressures that can be created at roof level around a flue cowl.

Balanced flue terminals (Outdoor models)

In practice it is almost impossible to achieve exact balance between the pressure on the

air inlet and flue outlet of a balanced flue terminal. In order to avoid the possibility of

reverse fluing the flue terminal design is always biased to provide slightly higher pressure

on the air inlet. The flue terminal on outdoor water heaters has the air inlet towards the

rear. When the water heater is installed against an external wall, the pressure zone

created by any wind will produce the required pressure balance for the flue terminal to

operate correctly. If the water heater is not installed against a wall, the pressures at the air

inlet and flue outlet become unpredictable, resulting in the combustion system not

operating correctly. Specifically, there may be flame roll out from the combustion chamber,

flame lift off from the burner, sooting of the primary flue and flue terminal and/or flame

failure problems. Below are 2 examples of the correct and incorrect installation of an

outdoor water heater.