39
Installation and operation manual
–
DTHR-V9-2020
Refer to the
flame safeguard alarms
section to get the right trouble description.
Troubleshooting table
Trouble description
Corrective action
• Flame failure
(code 7 and 19)
(see flame sensor lights code)
•
Verify gas supply as well as the pressure
•
Verify ignition transformer
•
Verify flame signal strength
•
Verify electric and manual valves opening
•
Verify flame ceramic detection probe and change the probe if necessary
•
Verify or replace the flame supervision relay amplifier
•
Verify and take a burner combustion test over the entire modulation range
•
Consult manufacturer
• Inter
lock alarms on flame
safeguard (code 21).
(see flame sensor lights code)
There are two possible safety devices in series on the flame safeguard
1
Maximum temperature (high limit)
safety switch (set to 160°F).
Its contact is normally closed (NC) and
opens if the exchanger air temperature
downstream higher than 160°F. The
switch is automatically reset when
temperature reduce.
Note: A cool down is needed before
resetting the alarm on flame safeguard.
During start-up or when running the unit
•
Verify air fan downstream temperature
(maximum temperature safety switch
opens at 160°F).
•
Verify the temperature sensor position
(need to read average temperature).
•
Verify burner modulation, all controls
and temperature signal.
•
Verify supply gas pressure.
•
Consult manufacturer.
2
High or Low gas safety switch
(gas train option FM or IRI)
If the gas pressure goes over the high or
lower the Low limit settings the burner will
stop or not start.
Note: Need to reset the switch before
resetting the alarm on flame safeguard.
During start-up or when running the unit
•
Measure the inlet gas pressure and
adjust as request on the name plate.
•
Measure the manifold gas pressure and
adjust as request on the name plate.
• Improper grounding
(code 54)
(see flame sensor lights code)
•
Verify the unit frame grounding and the flame supervision relay
•
Verify the grounding between the unit and the electrical distribution panel
•
Verify relay grounding
•
Mainstream wire and neutral wire are inverted.
•
Consult the manufacturer
• Improper grounding
(see flame sensor lights code)
•
Verify relay grounding
•
Mainstream wire and neutral wire are inverted.
•
Consult manufacturer
The table above lists the most common and important operational fault codes in the flame safeguard relay.
(Refer to flame safeguard instructions manual for other codes not listed in this table)
Flame safeguard troubleshooting
