Carrier 25VNA - Page 18

18
25VNA EVENT / FAULT (CONT.)
OPERATION
FLASH CODE
(Amber LED)
Heat or Cool
Mode
Po ssible Causes ACTION
System Malfunction 84
Both
Outside Normal Operating Range
(e.g.improperloadcalculation,sys-
tem match issue, outside cooling
range, outside heating range etc)
Consult Application Guidelines
loose High Pressure Switch harness
leads
Check HPS harness
Pressure Switch disconnected from
ODU Control Board
Check HPS connection on ODU control
Faulty Pressure Switch
Check Discharge pressure with gauge, if
less than 610 +/--- 20 psig and switch is
open (measure resistance) then replace
pressure switch
Restriction due to debris leading to
Overcharge when charging in C ool -
ing mode
Clean System (refer to application
guideline) and replace f ilter drier
Restriction in EXV plus Long Line
Application leading to Overcharge
when charging in Cooling mode
If long line, troubleshoot EXV
None condensible leading to high
load
Clean System (refer to application
guideline) and replace f ilter drier
Cool
Service Valve left closed (Liquid or
Vapor)
Ensure Service Valves are open
Overcharged System
Check system charge using Cooling
Charging Mode (follow proper charging
procedures)
Outdoor Airflow too low or off
Check Outdoor Coil for clogging (ice or
debris) and clean or de ---ice if neces-
sary; Troubleshoot Outdoor fan motor
and make sure it is working; follow Out-
door Airflow troubleshooting instruction
RestrictioninFilterDrierplusLong
Line Application and filter drier on
Outdoor Unit
Clean System (refer to application
guideline) and replace f ilter drier
RestrictioninEXVplusOvercharge troubleshoot EXV
Restriction in Circuits or Tubing
Check kinks and straighten or replace
circuits
Heat
Electric Heater plus Heat pump ap-
plication: Electric Heater stuck on
If User Interface is not requesting Electric
Heat check for heater relays, if on
troubleshoot Electric Heater
Furnace plus Heat pump applica-
tion: Furnace stuck on
If not in Defrost and Furnace is running
same time as heat pump, troubleshoot
Furnace
RestrictioninFilterDrierplusLong
Line Application and filter drier on
Indoor Unit
Clean System (refer to application
guideline) and replace f ilter drier
Expansion Orifice Restriction Troubleshoot TXV (see guide below)
Troubleshoot EXV (see guide below)
Service Valve left closed (Vapor
Service Valve)
Ensure Vapor Service Valve is open
Indoor Airflow too l ow or of f
Check Indoor for clogging (ice or debris)
and clean or de---ice if n ecessary;
Troubleshoot Indoor fan motor and
make sure it is working; follow Indoor
Airflow troubleshooting instruction
Overcharged System
Check charge in cooling (if in Cooling
Charge Mode Ambient Range), if low
add charge using Charging Mode (follow
proper charging procedures); if out side
coolingchargemoderange,pullout
charge, weigh in using heating charge
mode
Reversing Valve Stuck in Cooling troubleshoot reversing valve
Restriction due to debris
Clean System (refer to application
guideline) and replace f ilter drier