Navien NFC-250/200H User's Information Manual page 19

Addressing the Reported Problems
Inspect any problems reported by the owner and
correct before proceeding.
Inspecting the Installation Area
1. Verify that boiler area is free of any combustible
materials, gasoline and other flammable vapors
and liquids.
2. Verify that air intake area is free of any of the
contaminants listed in Installation & Operation
Manual. If any of these are present in the boiler
intake air vicinity, they must be removed. If they
cannot be removed, reinstall the air and vent
lines per the Installation and Operation Manual.
Inspecting the Boiler Interior
1. Remove the front cover and inspect the interior
of the boiler.
2. Vacuum any sediment from inside the boiler
and components. Remove any obstructions.
Cleaning the Condensate Trap
1. Inspect the condensate drain line, condensate
fittings, and condensate trap.
2. Remove any sediment in the trap.
3. Fill with fresh water until the water begins to
pour out of the drain.
Checking all Piping for Leaks
Eliminate all system or boiler leaks. Continual fresh
makeup water will reduce boiler life. Minerals
can build up in sections, reducing heat transfer,
overheating heat exchanger, and causing heat
exchanger failure. Leaking water may also cause
severe property damage.
1. Inspect all water and gas piping and verify to be
leak free.
2. Look for signs of leaking lines and correct any
problems found.
Checking the Flue Vent System and Air
Piping
1. Visually inspect the entire flue gas venting
system and air piping for blockage,
deterioration or leakage. Repair any joints that
show signs of leakage. Verify that air inlet pipe is
connected and properly sealed (if installed).
2. Verify that boiler vent discharge and air intake
are clean and free of obstructions.
WARNING
Failure to inspect for the above conditions and
have them repaired can result in severe personal
injury or death.
Checking the Water System
1. Verify all system components are correctly
installed and operational.
2. Check the cold fill pressure for the system. Verify
it is correct (must be a minimum of 6 psi).
3. Watch the system pressure as the boiler heats
up (during testing) to ensure pressure does not
rise too high.
If the system contains glycol,
Note
test for proper concentration as
recommended by manufacturer.
Excessive pressure rise indicates
expansion tank sizing or performance
problem.
4. Inspect automatic air vents and air separators.
Remove air vent caps and briefly press push
valve to flush vent.
5. Replace caps. Make sure vents do not leak.
Replace any leaking vents.
Maintaining the Boiler 19