Navien LCB700-21RS Installation & Operation Manual page 72

WARNING
Failure to inspect for the above conditions and have them
repaired can result in severe personal injury.
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 0.8 bar).
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, test for proper
Note
concentration as recommended by manufacturer.
Excessive pressure rise indicates expansion vessel
sizing or performance problem.
4. Inspect automatic air flues and air separators. Remove air
flue caps and briefly press push valve to flush flue.
5. Replace caps. Make sure flues do not leak. Replace any
leaking flues.
Inspecting the Flame Detector UV Sensor and Ignition
1. Remove the flame detector UV sensor at the bottom of the
burner by pulling it.
72 Maintaining the Boiler
2. Remove any deposits accumulated at the bottom of the UV
sensor.
3. Remove the fan and burner assembly.
4. Remove any deposit accumulated on the ignition.
Refer to the following illustrations and table for details
Note
about the ignition dimension.
Ignition