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2.
Connect a hose to the system drain valve.
3.
Locate hose's discharge in an area where hot water will not cause any damage or injury.
4.
Close the cold-water inlet valve to water heater system.
5.
Open a nearby hot water outlet to vent the system.
6.
Open the drain valve.
7.
If the water heater is being drained for an extended shutdown, it is suggested the drain valve be left
open during this period.
NOTE:
The heat exchanger cannot be completely drained of water without purging with compressed air
at a pressure of 1 bar.
15.7
STORAGE VESSEL: INSPECTION AND CLEANING
1.
Drain the heater. Refer to Section 15.6: DRAINING THE WATER HEATER SYSTEM.
2.
Remove outer cover plate from lower side of water heater jacket.
3.
Remove cover and gasket from cleanout opening.
4.
Remove scale or sediment using care not to damage the vitreous enamel lining.
5.
Inspect cleanout plate gasket and replace if necessary.
6.
Install gasket and cleanout plate. Draw plate up square by tightening screws evenly.
15.8
SACRIFICIAL ANODES: INSPECTION AND REPLACEMENT
If the Correx non-sacrificial anode protection system is used, there is no requirement to check the
condition of the anodes.
The tank is protected against corrosion by means of two sacrificial anodes fitted in the front of the storage vessel.
The rate at which the anodes are eroded is dependent on the quality of the water; therefore it is essential that the
anodes are inspected at least once a year.
1.
Drain the water heater. Refer to Section 15.6: DRAINING THE WATER HEATER SYSTEM.
2.
Remove the outer caps covering the anodes.
3.
Remove each anode and inspect its condition. If the anode has reduced in size by more than 40% or if
the surface is severely pitted, the anode should be replaced. Particular attention should be paid to the
ends of each anode to ensure excessive localised depletion has not occurred.
4.
When refitting the inspected or replaced anode, a suitable jointing compound should be applied to the
threads of the anode to prevent water leakage.
15.9
REFILLING THE SYSTEM
1.
Close the drain valve.
2.
Open a hot water fixture to allow air to escape.
3.
Open the cold water supply to water heater and allow the tank to fill.
4.
Follow the lighting instructions as detailed in Section 13.4.3: PROCEDURE FOR INITIAL LIGHTING.
5.
Check for water leakage.
15.10
OTHER CHECKS
15.10.1 RELIEF VALVE
At least once a year, the temperature and pressure relief valve and safety valve should be checked to ensure that
they operate correctly. To check the valves, the manual override levers should be operated several times. The
valves should seat properly and operate freely.
If water does not flow, drain the heater, remove the inoperative valve and inspect for obstructions or corrosion.
Replace with a new valve of the recommended size as necessary.
15.10.2 FLUE SYSTEM
Examine the exhaust and air intake system every 12 months. Points of inspection are as follows:
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