Replacement Parts Ordering; Model Number Designations; Serial Number Designations - Modine Manufacturing MT28 Installation And Service Manual

SERVICE & TROUBLESHOOTING / REPLACEMENT PARTS ORDERING
Table 11.1
Troubleshooting Continued
Trouble
Heater will not turn off
Dark spots on ceramic
Carbon formation on
ceramic surface of
burner
Low heater output
Gas odor
Control assembly
overheating
For Servicing
If a qualified service person cannot solve a problem with the installation, please consult with your local gas company or
sales representative.
When servicing, repairing or replacing parts on these units, locate the model identification plate of the unit and always give the
complete Model Number and Serial Number from the model identification plate. The serial plate is located on the side of the
reflector. For a complete description of the Model Number or Serial Number, see Figures 11.1 and 11.2.
Figure 11.1

Model Number Designations

MT 30
MT
High Intensity
Infrared Heater
Model
28
30
33
56
60
66
84
90
99
112
120
132
160
Possible Cause
1. Defective thermostat.
2. Gas valve stuck open.
3. Unit undersized.
1. Foreign matter behind the ceramic tile(s).
1. Misaligned orifice.
2. Pilot depositing carbon.
3. Obstruction in venturi tube.
4. Low gas pressure.
5. Wrong gas supplied to the heater.
1. Low inlet or manifold gas pressure
2. Orifice partially blocked with foreign matter.
3. Products of combustion not adequately vented. 3.
4. Manifold misaligned from excessive torque
applied at time of gas pipe installation.
5. Foreign matter in venturi tube.
6. Gas supply piping too small.
7. Unit undersized.
1. Loose pipe connection.
1. Heater not mounted correctly.
2. Heater mounted too close to ceiling.
G 47
Control Code
Direct Spark Ignition
47 - Natural Gas, 115V
48 - Natural Gas, 25V
97 - Propane Gas, 115V
75 - Propane Gas, 25V
Intermittent Pilot Ignition
04 - Natural Gas, 25V
08 - Natural Gas, 115V
Millivolt, Self-Energizing
27 - Natural Gas, Millivolt
67 - Propane Gas, Millivolt
Ignition
G - Spark Ignition
C - Standing Pilot, Millivolt System
1. Repair or replace thermostat.
2. Replace gas valve.
3. Check design conditions. If the unit is
undersized, additional heater(s) may be
required.
1. Clean ceramic tiles or replace.
1. Replace orifice.
2. Clean pilot burner, check pilot orifice.
3. Clean with a soft brush.
4. Provide proper gas pressure.
5. Check label for gas required.
1. Adjust for proper gas pressure.
2. Remove orifice, clean, and reinstall.
Provide adequate ventilation for products
of combustion.
4. Replace the manifold.
5. Clean with a soft brush.
6. Replace piping or increase gas supply
pressure.
7. Check design conditions. If unit is
undersized, an additional unit(s) or other
heat source must be added.
1. Check all connections with a soap solution
and tighten as necessary.
1. Angle to be 10
2. Check to main
Figure 11.2

Serial Number Designations

101 26 99 - 1256
SERIES IDENTITY
NUMBER
Identifies series of controls
WEEK OF
MANUFACTURE
01 – 1st week of year
26 – 26th week of year
Possible Remedy
° °
to 35 from horizontal.
t
ain proper top clearance.
SEQUENCE
NUMBER
YEAR OF
MANUFACTURE
99 – 1999
00 – 2000
etc.
11