General Maintenance - Modine HDS Serie Manuel D'installation Et D'entretien

servICe / mAInTenAnCe / TrouBlesHooTIng
WARNING
When servicing or repairing of this equipment, use only
factory-approved service replacement parts. A complete
replacement parts list may be obtained by contacting the
factory. Refer to the rating plate on the appliance for complete
appliance model number, serial number, and company
address. Any substitution of parts or controls not approved by
the factory will be at the owner's risk.
cAUTION
1. Servicing or repairing of this equipment must be performed
by a qualified service agency.
2. Do not attempt to reuse any mechanical or electrical
controllers which have been wet. Replace defective controller.
IMPORTANT
To check most of the Possible Remedies in the troubleshooting
guide listed in Table 17.1, refer to the applicable sections of
the manual.

general maintenance

The unit and venting system must be checked once a year by a
qualified service technician.
All installation and service of these units must be
performed by a qualified installation and service agency.
Before any service, Be sure To Turn off gAs AT THe
mAnuAl sHuT-off vAlve AHeAd of THe ComBInATIon
gAs ConTrol And Turn off All eleCTrIC poWer To
THe HeATer.
Table 17.1 - Troubleshooting
TrouBle possIBle CAuse
Unit does nothing 1. Power supply is off
2. No 24V power to thermostat
3. Thermostat malfunction
4. LED flashes
5. Defective control
LED light off or flashing 1. Multiple causes
Unit starts but does 1. Main gas is off
not ignite 2. Air in gas line
3. Main or manifold gas pressure
4. Check gas valve switch
Unit goes through cycle 1. Reversed main power polarity
but the burners go out in 2. Unit not grounded
less then 10 seconds 3. Flame not sensed
Air circulating fan 1. Loose connections
inoperable 2. Defective control board
3. Defective fan motor
1. Service air moving components annually.
a. Check fan for fit on motor shaft and for damage to blades.
2. Keep unit free from dust, dirt, grease, and foreign matter,
paying particular attention to:
a. Combustion air inlets.
b. Burners and burner orifices. Turn off gas ahead of the
combination gas control and shut off electric power to
the heater. Remove the access panel, open the union
on the gas line, and disconnect the igniter and sensor
wires. Remove the screws that attach the burner tray to
the header plate and remove the burner tray and manifold
assembly from the heater. Carefully clean the burners
with a wire brush or other suitable means.
Replace any damaged or deteriorating burners or orifices.
Install the burner assembly back on to the header making
certain that all screws, pipes and electrical connections are
tight.
CAuTIon : Be careful when handling the igniter and flame
sensor.
1. Inspect the flame sensor and igniter for deterioration
and/or cracks.
2. Verify that the burners are touching each other at the
carryover points. This will ensure flame carryover from
burner to burner.
c. Clean exterior of heat exchanger tubes.
d. Fan blade.
3. Check wiring for possible loose connections.
4. Controls – The gas valves and piping should be checked
annually for general cleanliness and tightness. The gas
controls should be checked to insure that the unit is
operating properly. See control instruction sheets furnished
separately with the unit heater.
5. Power exhaust assembly/motors – The power exhaust
motor bearings have been lubricated for long life and do not
require additional lubrication. In dirty atmosphere, it may be
desirable to clean the motors and blower housing and blow
out the cooling air passages of the motor with compressed air.
6. Perform periodic cleaning of inlet and vent terminal screens.
possIBle remedY
1. Turn on main power
2 a. Check control transformer
b. If failed transformer - check thermostat wire gage and length
3 a. Verify wire connections to R&W terminals only
b. Check / replace thermostat
4. Check LED flash code
5. Replace control
1. Control board LED flash codes vary with control type. A decal is
installed in the unit giving a brief description of the applicable codes
for your heater. For more detail, see the control board data sheet
included with this manual.
1. Open manual gas valve
2. Purge gas line
3. Set gas pressures per manual instructions
4. Set gas valve switch to "ON" position
1. Black wire - HOT, White wire - NEUTRAL, Green wire - Ground
2. Ground unit and verify quality of ground connection
3. Check flame sense probe and connection
1. Check all connections
2. Check control board data sheet and function
3. Check fan motor
6-584.2
17