LAARS NeoTherm NTV (Sizes 150–285 MBTU/h) - Service Manual - Manual (Page 43)

33 Service Manual NeoTherm 80 - NeoTherm 285
Checking the Air Pressure Switch - Blower Proving Switch
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 B16.)
Switch is OK? No Replace switch.
Yes
Problem with
blower?
Yes
See Section B18 -
“Checking the Blower”
No
Heat exchanger
is plugged?
Yes
Clean the heat
exchanger.
See Section C5.
B15