LAARS NeoTherm NTV (Sizes 399-850 MBTU/h) - Service Manual - Manual (Page 48)

38
Service Manual - NeoTherm 500
Exhaust vent
blocked?
Yes
No
Clear the vents.
Check the bird screens
or terminals.
Check for blocked air intake
and exhaust vents.
Clean with a shop-vac.
Dirty fan? Yes
No
Test the air pressure switch.
(See Section B20.)
Switch is OK? No Replace switch.
Yes
Problem with
blower?
Yes See Section B22 -
“Checking the Blower”
No
Heat exchanger
is plugged?
Yes
Clean the heat
exchanger.
See Section C5.
B19
Checking the Air Pressure Switch - Blower Proving Switch