A.O. Smith 110 Troubleshooting Manual - page 21
Troubleshooting Guide
21|
Page
DRAINING THE UNIT:
1) Close the manual gas shut off valve.
2) Turn off power to the unit, and then turn on again.
3) Wait 30 seconds, and then turn off power to the unit, yet again.
4) Close the cold water inlet shutoff valve.
5) Open all hot water taps in the house, or open the pressure‐relief valve to remove the initial
pressure. When the residual water flow has ceased, close all hot water taps.
6) Unscrewthe drain plugs (hot water outlet drain plug and cold water inlet filter) to drain the
remaining water out of the unit. Have a bucket or pan to catch the water from the unit’s
drain plugs. Wait a few minutes to ensure all water has completely drained from unit.
CLEANING THE FILTER:
1) Drain the unit (procedure above).
2) Check the water filter located within the
cold inlet. With a tiny brush, clean the
water filter of any debris which may
have accumulated and reinsert the filter
back into the cold water inlet.
3) Securely screw the filter back into place.
Hand‐tighten only.
CHECKING FOR A CROSS CONNECTION:
1)
Turn off cold water supply.
2)
Turn on all hot water fixtures.
a. The water should eventually completely drain.
b. If water continues to run, the fixtures and plumbing system needs to be checked.
c. Cold water cross connections may be related to a recirculation pump application, a
bad check valve, or missing check valve in the application.
CHECK FOR REVERSE CONNECTION:
1)
Close cold water supply at the inlet.
2)
Open the pressure‐relief valve; it should be installed on the hot side outlet of the unit.
3)
If water continues to run through the pressure‐relief valve, the system has a reverse
connection.
CHECK GAS SUPPLY PRESSURE:
1) Close the manual gas inlet shut off valve
on the gas supply line.
2) Open a faucet. The unit should turn on
and the gas in the pipe line should purge.
Leave the faucet on to keep the unit
running until it shuts down due to lack of
gas, and then shut the faucet off. Ignore
any error codes that may occur at this
time.
3) Remove the screw for the pressure port
located on the gas inlet shown on the right.
4) Connect a manometer to the pressure port.
Figure 17
Figure 18