14 • Residential Standard Gas Water Service Handbook
C
OMMON ISSUE
S
and early spring months. Even when
the water heater is working properly,
it may take longer to fully heat the
water. As a result, hot water may not
be available as quickly as it is during
warmer months.
Faulty Shower Control Valve/Faucet
Valve
Check the hot water at all faucets in
the home. Some may have built-in
thermostat or pressure-balance mixing
valves that may need adjustment or
replacement. If you get hot water from
some outlets but not others, adjust/
replace each fixture as necessary.
NOTE:
A mixing valve issue is not a
water heater defect and is not covered
by the water heater warranty.
Thermostat Set Too Low
Scalding Risk
A water heater can
make water hot
enough to cause
severe burns instantly, resulting
in severe injury or death. Higher
temperatures increase the risk of
scalding, but even at 120°F, hot water
can scald. See Table 2 on page 8
before proceeding. Thermostatic
mixing valves at each point of
use reduce the risk of scalding.
If you’ve checked all of the faucets
and shower controls and the water
temperature is still too cool, the water
heater’s thermostat may be set too
low. See “Temperature Settings” on
page 7 for instructions on how
to adjust the thermostat. If there
still isn’t enough hot water, set the
thermostat to a higher setting and
install a thermostatic mixing valve at
each point of use.
An Increase in Hot Water Usage
If hot water is running out during
holidays, weekends, or family
gatherings, the demand for hot
water may be exceeding the water
heater’s capacity. Hot water usage
can be reduced by washing clothes in
cold water, installing flow restrictors
on shower heads, and taking other
conservation steps.
Undersized Water Heater
If water is frequently too cool, the
water heater may be too small. If
the water heater is old, the best
solution may be to replace it with a
larger model. If the water heater is
in good condition, you may set the
thermostat to a temperature above
120°F and install thermostatic mixing
valves at each point of use. Set each
thermostatic mixing valve’s delivery
temperature to 120°F to reduce the
risk of scalding. (See “Temperature
Settings” on page 7.)
This method can increase the effective
size of the water heater by about 30%.
Reversed Water Connec ons
If the hot and cold water connections
are reversed, it may appear as if the
water heater isn’t producing much
hot water. This problem is usually
identified at the time of installation.
Confirm that the home’s hot water
pipe is connected to the water heater’s
hot water outlet, not the cold water
inlet. If the connections are reversed,
switch them to the correct position.
NOTE:
The water heater’s hot water
outlet will be marked with an “H” or
“HOT,” or will be color coded red.
Leak in the Plumbing System
A leak in the home’s plumbing system
can overload the water heater’s ability
to heat water. In that case, the water
heater can be working, but there will
be little or no hot water. Check the
plumbing system for leaks and repair
as necessary.
Sediment Buildup in the Tank
If the water heater is several years old
and/or is installed in an area known for
hard water, there may be a buildup of
sediment at the bottom of the tank.
Sediment buildup may reduce the
efficiency of the water heater and may
reduce the amount of available hot
water.
Drain and flush the tank (page 20).
You may also treat the tank with a
lime/scale removal solution that is
approved for potable water heaters.
