Functional & Performance Troubleshooting; Series - Heat Controller HTV Series Installation, Operation & Maintenance Manual

Installation, Operation & Maintenance
Functional Troubleshooting
Fault Htg Clg Possible Cause
Main power problems X
HP Fault
Code 2
X
High Pressure
X
X
X
LP/LOC Fault X
Code 3
X
Low Pressure / Loss of Charge
X
LT1 Fault
Code 4
X
Water coil low
X
temperature limit
X
X
LT2 Fault
Code 5
Air coil low
temperature limit
X
X
X
Condensate Fault
Code 6
X
x
Over/Under
X
Voltage Code 7
(Auto resetting)
X
X
Unit Performance Sentinel
Code 8
X
No Fault Code Shown X
X
X
X
Unit Short Cycles
X
X
X
X
Only Fan Runs X
X
X
X
Only Compressor Runs
X
X
X
Unit Doesn't Operate
in Cooling
HTV/HTD/HTH SERIES
X Green Status LED Off
X Reduced or no water fl ow in cooling
X Water Temperature out of range in cooling
Reduced or no air fl ow in heating
Air temperature out of range in heating
X Overcharged with refrigerant
X Bad HP Switch
X Insuffi cient charge
Compressor pump down at start-up
Reduced or no water fl ow in heating
Inadequate antifreeze level
Improper temperature limit setting (30°F vs
10°F [-1°C vs -2°C])
Water Temperature out of range
X Bad thermistor
X Reduced or no air fl ow in cooling
X Air Temperature out of range
Improper temperature limit setting (30°F vs
X
10°F [-1°C vs -12°C])
X Bad thermistor
X Blocked drain
X Improper trap
X Poor drainage
X Moisture on sensor
X Plugged air fi lter
X Restricted Return Air Flow
X Under Voltage
X Over Voltage
Heating mode FP2>125°F [52°C]
Cooling Mode FP1>125°F [52°C] OR FP2<
X
40ºF [4ºC])
X No compressor operation
X Compressor overload
X Control board
X Dirty air fi lter
X Unit in "test mode"
X Unit selection
X Compressor overload
X Thermostat position
X Unit locked out
X Compressor Overload
X Thermostat wiring
X Thermostat wiring
X
Fan motor relay
X
X Fan motor
X Thermostat wiring
X Reversing valve
X Thermostat setup
X Thermostat wiring
X Thermostat wiring
Solution
Check line voltage circuit breaker and disconnect.
Check for line voltage between L1 and L2 on the contactor.
Check for 24VAC between R and C on CXM/DXM'
Check primary/secondary voltage on transformer.
Check pump operation or valve operation/setting.
Check water fl ow adjust to proper fl ow rate.
Bring water temp within design parameters.
Check for dirty air fi lter and clean or replace.
Check fan motor operation and airfl ow restrictions.
Dirty Air Coil- construction dust etc.
Too high of external static. Check static vs blower table.
Bring return air temp within design parameters.
Check superheat/subcooling vs typical operating condition table.
Check switch continuity and operation. Replace.
Check for refrigerant leaks
Check charge and start-up water fl ow.
Check pump operation or water valve operation/setting.
Plugged strainer or fi lter. Clean or replace..
Check water fl ow adjust to proper fl ow rate.
Check antifreeze density with hydrometer.
Clip JW3 jumper for antifreeze (10°F [-12°C]) use.
Bring water temp within design parameters.
Check temp and impedance correlation per chart
Check for dirty air fi lter and clean or replace.
Check fan motor operation and airfl ow restrictions.
Too high of external static. Check static vs blower table.
Too much cold vent air? Bring entering air temp within design parameters.
Normal airside applications will require 30°F [-1°C] only.
Check temp and impedance correlation per chart.
Check for blockage and clean drain.
Check trap dimensions and location ahead of vent.
Check for piping slope away from unit.
Check slope of unit toward outlet.
Poor venting. Check vent location.
Check for moisture shorting to air coil.
Replace air fi lter.
Find and eliminate restriction. Increase return duct and/or grille size.
Check power supply and 24VAC voltage before and during operation.
Check power supply wire size.
Check compressor starting. Need hard start kit?
Check 24VAC and unit transformer tap for correct power supply voltage.
Check power supply voltage and 24VAC before and during operation.
Check 24VAC and unit transformer tap for correct power supply voltage.
Check for poor air fl ow or overcharged unit.
Check for poor water fl ow, or air fl ow.
See "Only Fan Operates".
Check and replace if necessary.
Reset power and check operation.
Check and clean air fi lter.
Reset power or wait 20 minutes for auto exit.
Unit may be oversized for space. Check sizing for actual load of space.
Check and replace if necessary
Ensure thermostat set for heating or cooling operation.
Check for lockout codes. Reset power.
Check compressor overload. Replace if necessary.
Check thermostat wiring at heat pump. Jumper Y and R for compressor operation
in test mode.
Check G wiring at heat pump. Jumper G and R for fan operation
Jumper G and R for fan operation. Check for Line voltage across BR contacts.
Check fan power enable relay operation (if present).
Check for line voltage at motor. Check capacitor.
Check thermostat wiring at heat pump. Jumper Y and R for compressor operation
in test mode
Set for cooling demand and check 24VAC on RV coil and at CXM/DXM board.
If RV is stuck, run high pressure up by reducing water fl ow and while operating
engage and disengage RV coil voltage to push valve.
Check for 'O' RV setup not 'B'.
Check O wiring at heat pump. Jumper O and R for RV coil 'click'.
Put thermostat in cooling mode. Check 24 VAC on O (check between C and
O); check for 24 VAC on W (check between W and C). There should be voltage
on O, but not on W. If voltage is present on W, thermostat may be bad or wired
incorrectly.
45
Heat Controller, Inc.