John Wood SERIES 100 - Manual (Page 24)

24
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.
CAUTION
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 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.
VENT SYSTEM
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.