A.O. Smith PHPT-80, 318257-000 Maintenance of Your Water Heater, Draining and Flushing

MAINTENANCE OF YOUR WATER HEATER

Temperature and Pressure Relief Valve

WARNING

Explosion Hazard

If the temperature and pressure relief valve is dripping or leaking, have a qualified person replace it.

Examples of a qualified person include: licensed plumbers, authorized electric company personnel, and authorized service personnel.

Do not plug valve. Do not remove valve.

Failure to follow these instructions can result in death or explosion.

Manually operate the temperature and pressure relief valve at least once a year to make sure it is working properly.

To prevent water
damage, the valve	Figure 11
must be properly		Temperature and Pressure
connected to a		Relief Valve
			Manual Relief
discharge line which			Valve
terminates at an
adequate drain.
Standing clear of the
outlet (discharged
water may be
hot), slowly lift and
release the lever
	Discharge line to drain
handle on the
temperature and

pressure relief valve to allow the valve to operate freely and return to its closed position. If the valve fails to completely reset and continues to release water, immediately disconnect the electrical power, close the cold water inlet valve and call a qualified person.

Draining and Flushing

It is recommended that the tank be drained and flushed every 6 months to remove sediment which may build up during operation. The water heater should be drained if being shut down during freezing temperatures. To drain the tank, perform the following steps:

1.Place the water heater in Standby Mode by pressing the power button on the user interface module.

2.Turn off the power to the water heater at the circuit breaker/fuse box.

3.Open a nearby hot water faucet until the water is no longer hot.

4.Close the cold water inlet valve.

5.Connect a hose to the drain valve and terminate it to an adequate drain or external to the building.

6.Open the water heater drain valve and allow all of the water to drain from the tank. Flush the tank with water as needed to remove sediment.

7.Close the drain valve, refill the tank (open the cold water inlet valve), and restart the heater as directed in this manual.

IMPORTANT: Do not turn on power to the water heater unless it is completely filled with water. To ensure that the tank is full, open a hot water faucet and allow the water to run until the air is purged and the water flows uninterrupted from the faucet.

8.Press the power button to turn the water heater on. NOTE: The water heater will conduct a system diagnostic prior to operation.

If the water heater is going to be shut down for an extended period, the drain valve should be left open.

Heating Element Replacement

WARNING

Electric Shock Hazard

Disconnect power before servicing.

Replace all parts and panels before operating.

Failure to do so can result in death or electrical shock.

Replacement heating elements must be of the same style and voltage/wattage rating as the ones originally in the water heater. This information can be found on the flange or terminal block of the element or on the water heater data plate.

IMPORTANT: Before replacing any element confirm that you have the correct replacement element (wattage). This water heater has a 4500 watt upper element and a 2000 watt lower element. DO NOT replace the element(s) with a wattage different than the ones specified for the upper and/ or lower element.

IMPORTANT: Using an element greater than 2000 watts in place of the lower element will damage the water heater and void the warranty.

1.Press the power button on the user interface module to place the water heater in Standby Mode.

2.Turn off the power to the water heater.

3.Drain the water heater as directed in the “Draining and Flushing” section.

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