Lennox MPB012S4S

119
Error Code: P2
Description: Lowpressureswitchopen.
General Note: Ifthesamplingvoltageisnot5V,theLEDwilldisplaythefailure.
LowPressureConnection
Isthewiringbetweenthelowpressureswitchand
main control board is connected properly.
Yes
Isthelowpressureprotectorbroken?
Method:Disconnecttheplug.Measuretheresistance
ofthelowpressureprotector,iftheprotectorisnormal
thevalueis0.
Yes
Connect it properly..
No
Replacelowpressureprotector.
No
Checkwhethertheoutdoorambienttemperatureisto
low.
No
Stoptheunit.
Yes
Checkwhetherthehighpressurevalveisopened.
Yes
Fullyopenthehighpressurevalve.
No
Checkiftheindoorfanrunsproperlyincoolingmode.
Refertothesolutionoffanspeedmal-
function(E8).Findoutthecausecorrect
it.
No
Yes
Replaceoutdoormainboard.
No
Refrigerantisnotenough.Addtherefrigerant.