Drain Valve And Access Panels; Relief Valve; Circulating Pump; Vent System - A.O. Smith SERIES 100 Installation & Operating Instructions Manual

DRAIN VALVE AND ACCESS PANELS

The heaters are equipped with a 3/4" drain valve.
An access panel covers the cleanout opening in the tank which is sealed
by a gasket and cover, figure 25.

RELIEF VALVE

At least twice a year, the temperature and pressure relief valve should be
checked to ensure that it is in operating condition. To check the relief valve,
lift the lever at the end of the valve several times. The valve should seat
properly and operate freely.
If water does not flow, remove and inspect for obstructions or corrosion.
Replace with a new valve of the recommended size as necessary.
Inspection of the valve should be performed at least every three years. Do
not attempt to repair the valve, as this could result in improper operation
and a tank explosion. In areas with poor water conditions, it may be
necessary to inspect the T&P valve more often than every three years.
BEFORE MANUALLY OPERATING THE VALVE, MAKE SURE THAT A DRAIN
LINE HAS BEEN ATTACHED TO THE VALVE TO DIRECT THE DISCHARGE TO
AN OPEN DRAIN. FAILURE TO TAKE THIS PRECAUTION COULD MEAN
CONTACT WITH EXTREMELY HOT WATER PASSING OUT THE VALVE
DURING THIS CHECKING OPERATION.
If the temperature and pressure relief valve on the heater discharges
periodically or continuously, it may be due to thermal expansion of water in
a closed water supply system, or, it may be due to a faulty relief valve.
Thermal expansion is the normal response of water when it is heated. In
a closed system, thermal expansion will cause the system pressure to
CAUTION
build until the relief valve actuation pressure is equaled. Then, the relief
valve will open, allowing some water to escape, slightly lowering the
pressure.
Contact your water supplier or local plumbing inspector on how to control
this situation.
Two common corrections are listed in the Checklist and Service Information
which appears later in this manual.
ABOVE ALL, DO NOT PLUG THE TEMPERATURE AND PRESSURE RELIEF
VALVE. THIS IS NOT A SOLUTION AND CAN CREATE A HAZARDOUS
SITUATION.

CIRCULATING PUMP

The water heating system may include a circulating pump. Where used, it
should be lubricated as directed by the circulator manufacturer.
Examine the vent system every 3 months. Points of inspection are as
follows:
1. Check for obstructions and/or deterioration of vent piping and vent
hood. Replace immediately where needed.
2. Vent pipe and vent hood screen should be cleaned of foreign material
and soot. The screen is located inside the vent hood outlet and is
accessible from the outside of the hood. Do not reach inside the vent
hood when the heater is in operation.
3. Check all vent system connections for leakage and reseal as required
using Hi Temp Silicone sealer or equivalent.
27

VENT SYSTEM