Detroit Radiant Products Company MP Series - Manual (Page 22)

22
MP Series 4.0 Troubleshooting Guide
4.0 Troubleshooting Guide
Turn on control
device for heat.
Does the fan
blower turn on?
Is the control
device or
thermostat wire
damaged?
Replace or
repair damaged
components .
No
Does the
pressure switch
light turn on?
Yes
Does the igniter
warm up and
turn red?
Yes
Yes
Does the heater
have 120VAC at
the power entry
cord?
Find source of
electrical problem
and repair .
No
No
Yes
Does the igniter
warm up and turn
red?
No
Pressure switch light is burned out .
Replace light .
Yes
Does the igniter
appear to be
physically
damaged?
Yes
Replace igniter .
Temporarily disconnect igniter
from harness and check the
resistance . Is it within the
range of 50-400 Ohms?
No
No
Replace igniter .
Yes
Continued on Page 24
Does the valve
light turn on?
Yes
No
Does the gas
valve open?
Yes
Does the gas valve open?
(Usually a distinct
‘click’ noise occurs) .
No
Yes
Check inlet pressure to
the heater . Is it within the
minimum and maximum
allowable range as per the
rating plate?
No
No
Adjust inlet pressure .
Yes
Are the wires
to and from
the gas valve
properly
connected?
No
Gas valve light is burned
out . Replace light .
No
Continued on Page 24
Yes
No