Residential Standard Gas Water Heater Service Handbook • 15
C
OMMON ISSUE
S
Tank Leak
Condensa
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on
If you see small puddles of water in
the drain pan or hear sizzling sounds
as water drips on the burner, the
water heater may be producing
condensation. Condensation may drip
onto the burner or other hot surfaces
to produce a sizzling sound. On some
models, this may actually cause the
pilot to go out.
Condensation usually occurs when the
water heater tank is full of cold water.
Condensation will most likely occur:
• During holidays, weekends, or
family gatherings when there is an
increase in your home’s hot water
usage.
• During the winter and early spring
months when incoming water
temperatures are at their lowest.
• If the water heater is a new
installation.
• If a large amount of hot water is
used in a short period of time.
• If the water heater is too small for
the home’s hot water demands.
In most cases, condensation
should disappear once the water
heater reaches normal operating
temperature, or when the home’s hot
water demands return to normal.
If the water heater is too small for the
home’s typical hot water demands,
the water heater may produce
condensation regularly. In that case, a
larger water heater is recommended.
NOTE:
Condensation may cause a “2
Flashes” error code, indicating low
thermopile voltage. This condition
may clear up as the tank begins to
warm. See “2 Flashes” on page 10
Leaking Plumbing Connec
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ons
If there’s water on the floor around
the bottom of the water heater, check
the plumbing connections on top of
the tank. Use a dry paper towel to
wipe around the hot and cold pipe
connections on top of the water
heater. If the paper towel is wet after
wiping a connection, repair the leak(s).
Drips from the T&P Relief Valve
Discharge Pipe
A small amount of water dripping from
the temperature and pressure (T&P)
relief valve usually means the home’s
water pressure is too high or you
need a properly sized and pressurized
thermal expansion tank. A large
amount of hot water coming from the
T&P discharge pipe may be due to the
tank overheating.
WARNING!
Do not cap or plug the
T&P relief valve or discharge pipe,
and do not operate the water heater
without a functioning T&P relief Valve.
This could cause an explosion.
Refer to Figure 1 on page 6 while
reviewing this section.
•
Water pressure too high.
High water
pressure can cause the T&P relief
valve to drip. Install a pressure
reducing valve (PRV) on the main
cold water supply line. Adjust the
PRV to between 50 and 60 psi.
•
Thermal Expansion Tank.
Install
a Thermal Expansion Tank. If a
Thermal Expansion Tank is already
installed and the T&P Relief Valve
discharge pipe drips, the Thermal
Expansion Tank may be pressurized
to the wrong pressure or the internal
bladder may be defective. Refer to
the instructions that came with the
Thermal Expansion Tank for more
information.
•
Debris.
In rare cases, debris can
stick inside the T&P relief valve
preventing the valve from seating
fully. In that case, the T&P relief
valve discharge pipe will drip. You
may be able to clear debris from
the T&P Relief Valve by manually
operating the valve, allowing small
quantities of water to flush out the
debris. See the label on the T&P
relief valve for instructions.
If the water pressure is between 50
and 60 psi, a thermal expansion tank is
installed and properly pressurized, and
the valve has been cleared of any debris,
and it still drips, the valve may be broken.
Install a new T&P relief valve.
