Lennox DVR5-CMNS User Manual

28
TROUBLESHOOTING THE MILLIVOLT GAS CONTROL SYSTEM
MODELS _DVR5-CMNS, _DVR5-CMPS, _DVR5-RMNS AND _DVR5-RMPS
Note:
Before
troubleshooting
the
gas
contro!
system,
be
sure
external
gas
shut
off
valve
(located
at
gas
supply
inlet)
is
in
the “ON” position.
SYMPTOM
POSSIBLE CAUSES
CORRECTIVE ACTION
1. Spark ignitor will not light
pilot after repeated
triggering of red button.
. Defective ignitor
(no spark at electrode).
Check for spark at electrode and pilot; if no spark and electrode
wire is properly connected, replace ignitor.
. Defective or misaligned electrode
at pilot (spark at electrode).
Using a match, light pilot. If pilot lights, turn off pilotand trigger
the red button again. If pilot lights, an improper gas mixture
caused the bad lighting and a longer purge period is recom-
mended. if pilot will not light check gap at electrode and pilot
- should be ¥%" to have a strong spark. If gap measures %',
replace pilot (Figure 23 ).
. Gas supply pressure errant.
Check inlet gas pressure. It should be within the limits as
marked on the rating plate.
. Pilot orifice piugged.
Clean of replace pilot orifice.
2. Pilot will not stay lit after
carefully following the
lighting instructions.
. Defective pilot generator (thermo-
couple).
Check pilot flame, it must impinge on thermocouple (Figure
23). Clean and/or adjust pilot for maximum flame impingement
on thermocouple. Ensure that the connection between the valve
and thermocouple are tight and secure.
3. Piiot burning, no gas to
burner, Valve knob “ON,”
Wall Switch “ON.”
. Wall switch or wires defective.
Check wall switch and wires for proper connections. Jumper
wire across terminais at wall switch, if burner comes on, replace
defective wall switch. If okay, jumper wires across wall switch
wires at valve, If burner comes on, wires are faulty or connec-
tions are bad.
. Thermopile may not be generating
sufficient millivoltage.
Check thermopile with millivolt meter. Take reading at thermo-
pile terminals of gas valve. Should read 325 millivolts minimum
with optional wall switch “OFF.” Replace faulty thermopile if
reading is below specified minimum.
. Plugged burner orifice.
Check burner orifice for stoppage and remove.
. Defective door switch (located at
lower right corner of door frame).
Remove door frame (see instructions).
Remove two (2) screws from switch mounting bracket, pull
switch out.
Jumper wire across terminals of door switch.
lf burner comes on, door switch is defective. Replace.
4. Frequent pilot outage
problem.
. Pilot flame may be too low or
blowing (high) causing the pilot
safety to drop out.
Clean and/or adjust pilot flame for maximum flame impingement
on thermocouple (Figure 23).
5. Frequent burner outage
problem.
. Pilot flame may be too low or
blowing (high) causing the valve
safety to drop out.
Clean and/er adjust pilot flame for maximum flame impinge-
ment on thermopile (Figure 23).
f i r e - p a r t s . c o m

Lennox DVR5-CMNS Specifications

General

Brand	Lennox
Model	DVR5-CMNS
Category	Fireplace Accessories
Language	English