16
Water Heater Maintenance
Maintenance Schedule
Annual service by qualified service technician
should include the following:
Any procedure required by local codes.
Check air vent operation.
Verify system pressure. Air venting proce-
dure may require adding water to bring sys-
tem up to pressure, typically 12 psig.
Manually operate T&P relief valve at least
once a year. This will release some hot
water.
Before operating T&P relief valve, make
sure no one is in front of or around T&P
relief valve discharge piping. Hot discharge
water can cause severe personal injury or
substantial property damage.
Move operating lever to open position for a
few seconds and then move it back, allowing
it to snap closed. After T&P relief valve is
operated, if it continues to release water,
close cold water inlet to water heater imme-
diately. Follow draining instructions, and
replace T&P relief valve. If T&P relief valve
weeps periodically, it may be due to thermal
expansion see Thermal Expansion, page 6.
Do not plug T&P relief valve or discharge
piping.
Plugging T&P relief valve or discharge pip-
ing can cause excessive pressure in water
heater, resulting in severe personal injury,
death, or substantial property damage.
Follow instructions on circulator to oil it, if
required.
Check mixing valve, valves, pipes and fit-
tings for leaks.
Check function of field-installed controls
and valves. See component manufacturer’s
instructions.
Review homeowner’s maintenance responsi-
bilities and their frequencies, including any
not listed in the following section.
Homeowner monthly maintenance to include:
Check air vent operation.
• Automatic air vent - remove cap. Briefly
push in valve and release it to clean valve
seat. Screw cap on completely, then
unscrew one full turn. If air vent does not
operate, call qualified service technician.
Visually check valves, pipes and fittings for
leaks. Call qualified service technician to
repair leaks.
Filling Water Heater
See “Filling the Outer (Boiler Water) Tank” and
“Filling the Inner (Domestic Water) Tank on page
11.
Draining Water Heater
Drain water heater if it will be shut off and exposed
to freezing temperatures. Freezing water will
expand and damage water heater.
• If boiler water contains sufficient
antifreeze, then only the domestic water
needs to be drained.
Close boiler water isolation valves and
relieve system pressure to below 15 psig in
outer tank before draining inner tank to
prevent damage to inner tank.
• If boiler water does not contain sufficient
antifreeze, then the boiler water and
domestic water must be drained.
WARNING
WARNING
WARNING
