John Wood Direct Vent Models No Longer in Production - Manual (Page 11)

VIII) MAINTENANCE INSTRUCTIONS
GENERAL HOUSEKEEPING
As a precaution against fire, and to maintain an adequate
flow of combustion air to the heater:
• keep the appliance area clear and free from com-
bustible material, gasoline, and other flammable
vapours and liquids.
• keep the terminal openings unobstructed.
• do not pile cartons, paper or combustible material on
top of the heater.
TANK
Drain at least a pail of water from the drain valve once a
month. Some deposit will be washed out of the tank. If
larger particles, resembling coarse sand are washed out,
or if the drain becomes clogged while draining, an excess
of lime deposit has settled on the tank bottom and it is
time to do a major tank cleaning. Consult your local Gas
Utility or a qualified serviceman.
VENTING SYSTEM INSPECTION
Every 3 months, when inspecting the burner flame, an
inspection of the venting system should be made.
Check these points:
1. To make certain vent terminal is securely attached
and free of obstruction.
2. Inspect air pipe to make certain its components are
securely fastened, sealed and are in good condition.
3. To make certain inner door on water heater is secure-
ly fastened.
CORRECT ANY DEFECTS IMMEDIATELY.
TEMPERATURE & PRESSURE RELIEF VALVE
The Temperature and Pressure Relief Valve (T&P valve)
is a part of the safety equipment on the water heater. In
order to keep the T&P valve functioning properly, operate
the valve at least once a year by lifting the manual lever
until water discharges from the overflow pipe.
CATHODIC PROTECTION
Depending on the model, one or two magnesium anodes
are factory installed inside the tank to provide corrosion
protection and to extend tank life. Permanent removal of
the anode(s) for any purpose will void the warranty. Read
the warranty attached to this water heater for a full expla-
nation of the time period that parts and the heater are
warranted.
It is advisable to inspect the condition of the anode(s) at
certain intervals. A 2 year period may be a guide to begin
with. The life of the anode depends on many factors and
can differ greatly from one location to another.
To remove an anode, proceed as follows:
1. Turn the gas off at the inlet to the heater.
2. Turn water off at the cold water inlet valve.
3. Open a nearby hot water tap.
4. Drain approximately one pail full of water from the
heater.
5. With a 1-1/16 in. hexagon socket wrench, loosen the
anode from the fitting in the tank top.
NOTE: The anode has been factory installed using a
power tool. It will be necessary for a second person to
restrain the heater. A few sharp blows on the handle of
the socket wrench will loosen the anode nut.
If an impact wrench (power drive) is available, this is
an easy way to remove an anode.
6. Lift the anode up and inspect. There should be at least
10mm (3/8 in.) to 12mm (1/2 in.) of anode diameter
left. The surface may be rough, full of pits and
crevices, but this is normal.
If there is less than approximately 10mm (3/8 in.)
diameter left, the anode needs to be replaced.
7. Apply a good grade of pipe dope to the threads of the
anode adaptor and screw securely into the tank top.
8. Open a hot water faucet and the cold water inlet
valve and fill tank.
9. Check for leaks.
10. Relight burner by following lighting instructions on
page 8 or 9.
Water supply conditions may vary depending on the
region where this water heater is installed, and in some
cases the water may have an adverse effect on the oper-
ation of the anode. If a sulphurous, or “rotten egg” smell
is noticeable in the hot water supplied by this heater, it is
an indication that the water source is not compatible with
the magnesium anode which is factory installed. Replace
the anode with an aluminum anode or add a water treat-
ment system to remove sulphur from the water supply.
- 11 -
CAUTION
The water flowing from the valve will be HOT.
Keep hands and feet away from the stream of
water. Take care that the discharging water does
not damage any flooring, carpeting or other parts of
the building which may be damaged by water.
See also section on T&P valve in the installation
section.