To Flush the tank perform the following steps:
1.Turn off the electrical supply to the water heater.
2.Ensure the cold water inlet valve is open.
3.Open a nearby hot water faucet and let the water run until the water is no longer hot. Then close the hot water faucet.
4.Connect a hose to the drain valve and terminate it to an adequate drain.
5.Ensure the drain hose is secured before and during the entire flushing procedure. Flushing is performed with system water pressure applied to the water heater.
6.Open the water heater drain valve to flush the storage tank.
7.Flush the water heater storage tank to remove sediment and allow the water to flow until it runs clean.
8.Close the water heater drain valve when flushing is completed.
9.Remove the drain hose.
10.Fill the water heater - see Filling The Water Heater on page 50.
11.Turn on the electrical supply to place the water heater back in operation. See Initial Start Up on page 50.
12.Allow the water heater to complete several heating cycles to ensure it is operating properly.
Filling The Water Heater
See Filling The Water Heater on page 50.
Sediment Removal
Waterborne impurities consist of the particles of soil and sand which settle out and form a layer of sediment on the bottom of the tank.
For convenience, sediment removal and lime scale removal should be performed at the same time.
Lime Scale Removal
When water is heated dissolved minerals in the water such as calcium and magnesium carbonate (lime scale) become less soluble. As the water temperature rises these minerals will precipitate or “fall out” of solution.
The amount of lime scale released from water is in direct proportion to water temperature and usage. The higher the water temperature or water usage, the more lime deposits are dropped out of the water.
Water hardness also affects lime scale accumulation. With the temperature and usage being the same, hard water will release more lime scale than softer water.
Lime scale reduces heating efficiency as it accumulates inside a water heater. Heating transfer surfaces become coated with lime scale deposits which increases fuel costs to operate the water heater. Lime scale deposits can also cause rumbling and pounding noises as air molecules trapped in the lime scale escape when heated. Lime scale accumulation also reduces the life span of water heaters. For these reasons a regular schedule for deliming should be set up.
The depth of lime accumulation in the bottom of the water heater should be measured periodically. Inspect by removing the cleanout cover once every 6 months at first. Deliming maintenance should then be performed based on the time it takes for 1 inch (2.5 cm) of lime to accumulate in the bottom of the water heater.
Sediment and lime scale removal may be accomplished manually through the cleanout opening furnished on the water heater, see Figure 58.
CLEANOUT
TANK ACCESS PANEL
CLEANOUT CLEANOUT
OPENING GASKET
CLEANOUT 
COVER
Figure 58
Manual Lime Scale Removal
Note: Contact your local distributor or call the parts department phone number on the back cover of this manual to order a new cleanout gasket. Have the new gasket available before removing the cleanout cover.
The cleanout opening is shown in Figure 58. To remove lime scale manually through the cleanout opening proceed as follows:
1.Turn off the electrical supply to the water heater.
2.The water heater must be drained, see Draining And Flushing on page 60, follow the instructions on how to drain the water heater.
3.Remove outer cleanout access plate from lower side of the water heater jacket.
4.Remove the cleanout cover from cleanout opening.
5.Remove lime, scale and/or sediment using care not to damage the
6.Install a new cleanout gasket if required.
7.Reinstall the cleanout cover. Be sure to draw plate up tight by tightening screws securely.
8.Close the water heater drain valve.
9.Fill the water heater - see Filling The Water Heater on page 50.
10.Turn on the electrical supply to place the water heater back in operation. See Initial Start Up on page 50.
11.Allow the water heater to complete several heating cycles to ensure it is operating properly.
12.Check for water leakage.
13.Reinstall the cleanout access plate.
Chemical Lime Scale Removal
To dissolve and remove more stubborn lime scale deposits, UN- LIME® Professional Delimer should be used.
Follow the instructions on the
Note: Call the parts department phone number on the back cover of this manual to order
61