Detroit Radiant Products Company MP Series - Manual (Page 25)

25
MP Series 4.0 Troubleshooting Guide
Check for flash codes on the modulating controller .
Replace the ignition module .
Is there 24VAC on the
secondary side of the
transformer across the
BLUE and YELLOW wires?
Yes
Is the relay switching
closed when energized
by the 120V coil?
Yes
Disconnect the main
wire to the valve and
check for resistance
across both coil pins .
Is there continuity
through each coil?
No
Is there 120VAC on the primary
side of the transformer across
the BLACK and WHITE wires?
Check wiring and repair .
Replace transformer .
Yes
No
No
Replace isolation relay .
No
Replace gas valve .
No
Replace valve wire .
Adjust inlet pressure .
Were the
gas lines purged of air?
Purge gas lines .
Yes
Does the heater’s gas
type match the gas
supplied?
Check manifold
pressure . Are you
reading within the
specified pressures?
No
Contact local
representative or
factory .
No
Check modulating controller
for flash codes . Consult
factory .
Yes
Is the heater properly grounded?
Is the heater’s polarity correct
(L1 and L2 reversed)?
No
Yes
No
Correct grounding
or fix polarity .
Yes
With a micro ammeter, check the
micro Amps on the FS terminals
on the ignition module . Is it
greater than 0 .7 Micro-Amps?
Check modulating controller
for flash codes . Replace
ignition module .
Yes
No
Is the insulation
of the flame rod
damaged or is the
rod dirty or oxidized?
Replace flame rod or
clean if able .
Yes
No Replace wire to
flame rod .