Detroit Radiant Products Company MP Series - Manual (Page 24)

24
MP Series
Re-cycle the unit . Check
manifold pressure during
start-up . Is it with the ranges
specified on the rating plate?
Check inlet pressure to the
heater . Is it within the minimum
and maximum allowable range
as per the rating plate?
4.0 Troubleshooting Guide
Continued from Page 22
Check the voltage at
the relay coil during the
ignition sequence .
Is it 120VAC?
Yes Yes
Continued from Page 22
Yes
Does the burner
ignite?
Yes
Does the burner
stay lit?
Yes
Is the heater
output consistent
with prior
operation?
Yes
Does the heater
stay on until the call
for heat ends?
Troubleshooting ends.
For additional information, contact your local
representative or the factory for assistance .
Yes
No
No
No
The heater can shut down or stay on due to:
• Improper grounding .
• Faulty control device .
• High winds .
• Taking combustion air from the attic .
• Dirty environment .
• Improperly positioned baffles .
• Fluctuating gas pressure .
Is the gas supply valve
to the heater in the “on”
position?
Turn on the gas supply line .
No
Yes
No
No
Does the burner light and
then shut off immediately
(1-2 seconds)?
Does the burner stay
on for approximately
8 seconds and then
shut off?
Yes
Check modulating controller for
flash codes . Consult factory .
No
Yes
Consider the following:
• Change mode selection .
• Addition of a room thermistor .
• Addition of wind barriers .
• Check heat loss calculation .
• Consult factory .
Yes No
Check inlet pressure to the
heater . Is it within the minimum
and maximum allowable range
as per the rating plate?
No
Adjust inlet pressure .
Partial blockage in the venting may
be present . Check for obstructions
and check flash codes .
Yes
No
Pressure switch may be faulty or
there is a restriction in the exhaust .
Confirm inlet is within minimum
and maximum inputs as indicated
on the rating label .
Is the gas pressure ok?
No
Yes
Yes