John Wood Commercial - AJWSC - Manual (Page 24)

Draining and Flushing
It is recommended that the tank be drained and flushed
every 6 months to remove sediment which may buildup dur-
ing operation.
Note: Warranty is null and void in the event lime & scale
deposits are allowed to exceed two inches in depth.
The water heater should be drained if being shut down dur-
ing freezing temperatures. To drain the tank, perform the fol-
lowing steps:
1. Turn off the gas to the water heater at the manual gas
shut-off valve and turn off electricity.
2. Close the cold water inlet valve.
3. Open a nearby hot water faucet.
4. Connect a hose to the drain valve and terminate it to an
adequate drain.
Note: The drain hose should be rated for at least 93°C
(200°F). If the drain hose does not have this rating, open the
cold water inlet valve and a nearby hot faucet until the water
is no longer hot.
5. Open the water heater drain valve and allow all the
water to drain from the tank.
6. Remove the screws holding the cleanout plate, then
remove the plate for access.
7. Remove any lime, sediment, or scale from the tank. Be
careful not to damage the glass lining.
8. Flush the tank with water as needed to remove any
remaining sediment.
9. Check gasket on cleanout plate, replace if necessary.
10. Replace the cleanout plate and screws, tighten suffi-
ciently.
11. Close the drain valve, refill the tank, and restart the
water heater as directed under “Lighting & Operating
Instructions”.
If the water heater is going to be shut down for an extended
period, the drain valve should be left open.
Important: Condensation may occur when refilling the tank
and should not be confused with a tank leak.
Routine Preventative Maintenance
At least annually, a visual inspection should be made of the
venting and air supply system, piping systems, main burner,
and pilot burner. Check the water heater for the following:
• Obstructions, damage, or deterioration in the venting sys-
tem. Make sure the ventilation and combustion air sup-
plies are not obstructed.
• Build-up of soot and carbon on the main burner and pilot
burner. Check for a soft blue flame.
• Leaking or damaged water and gas piping.
• Presence of flammable or corrosive materials in the
installation area.
• Presence of combustible materials near the water heater.
• Verify proper operation after servicing this water heater.
Important: If you lack the necessary skills required to prop-
erly perform this visual inspection, you should not proceed,
but get help from a qualified service technician.
Temperature and Pressure Relief Valve
Manually operate the temperature and pressure relief valve
at least once a year to make sure it is working properly (See
Figure 23). To prevent water damage, the valve must be
properly connected to a discharge line which terminates at
an adequate drain. Standing clear of the outlet (discharged
water may be hot), slowly lift and release the lever 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 turn off the gas at the manual gas shut-
off valve, the electric power and the cold water inlet valve
and call a qualified service technician.
Pilot Burner and Main Burner Assembly
Inspection
To access the pilot burner and main burner for inspection:
1. Turn off gas at main shutoff valve and turn off electrical
power.
2. Disconnect the gas supply line from the gas valve.
3. Remove the 2 screws holding the Pilot & Main Burner
Assembly in place. See Figure 24 for location of screws.
4. Carefully slide the assembly out of the water heater.
5. If needed, use a brush or vacuum to clean any soot or
debris from the burners.
6. Check for correct alignment of burners before sliding
assembly back into the water heater.
7. Carefully slide Pilot/Burner Assembly back into the
water heater.
VII) MAINTENANCE
Temperature and Pressure
Relief Valve
Manual Relief Valve
Discharge line to drain
Figure 23 T&P Valve Test
WARNING
Explosion Hazard
• If the temperature and pressure relief
valve is dripping or leaking, have a
licensed plumber repair it.
• Do not plug valve.
• Do not remove valve.
• Failure to follow these instructions can
result in death or an explosion.
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