Water Drain Valve (With Water Filter); Periodic Maintenance - Noritz NR50-OD Service Manual

Water Drain Valve (with Water Filter)

If the water drain valve (with water filter) is covered with debris, the hot water may not run
smoothly, or the unit may put out cold water. Check and clean the filter as explained below.
* To avoid burns, wait until the equipment cools down before draining the water.
The appliance will remain hot after it is turned off.
1. Close the water supply valve.
2. Open all hot water fixtures.
3. With a bucket ready, remove the inlet and outlet
drain plugs (up to 0.5 gal. will drain out)
4. Take the water drain valve (with water filter) out
of the inlet. (See illustration to right).
5. Clean the water drain valve (with water filter) with
a brush under running water.
6. Replace the water drain valve (with water filter)
and close the drain plugs.
(Take care not to lose the packing.)
7. Close all hot water fixtures.
8. Open the water supply valve and check that
water does not leak from the drain plugs or water
drain valve (with water filter).
If the unit becomes saturated with lime or scale build-up, the hot water may not run smoothly, or the unit
may put out cold water. In addition, damage can occur resulting in failure of the unit if lime or scale
deposits are left untreated within the unit. To remove these deposits from the unit, follow the procedure
as explained below. To ensure full warranty coverage, hard, acidic, or otherwise impure water should be
treated with approved methods.
Note : Isolation valves will need to be installed in order to perform this procedure.
1. If not already on, turn the unit on with the Power Button on the Remote Controller.
2. Close the gas supply valve.
3. Close both the hot and cold water valves with a quarter turn of the main valve wing handle.
The handle will be perpendicular to the main valve body.
4. Ensure the drain valve lever handles are closed on both the hot and cold valves (the lever
will be perpendicular to the drain portion of the body) and slowly remove drain caps. Be sure to
retain the rubber washer inside of the drain cap.
5. Connect the pump outlet hose to the cold water drain valve of the isolation valve as shown in Figure 1.
6. Connect a drain hose to the hot water drain valve outlet of the isolation valve as shown in Figure 1.
7. Pour approximately 5 gallons of virgin food grade white vinegar or a solution of Lime Away
(or CLR) and water (diluted 3 parts water to 1 part Lime Away or CLR) into a bucket.
8. Place both the pump inlet hose and the drain outlet hose into the pail.
9. Open both drain valve lever handles on the isolation valves.

Periodic Maintenance

Periodic Maintenance
<continued on next page>
89
Inlet
Packing
Water drain valve
(with water filter)
Packing
Lid
Water Supply
Valve
Water drain valve
(with water filter)
For NC380-SV-ASME/N-1321M-ASME
Inlet