Midco Economite RE4400DS - Manual (Page 12)

12
VALVE terminal and the other Electronic Control VALVE . No voltage,
defective Electronic control.
2. Check for 24V* between valve MV terminal and valve body: With voltage, RESET
Electronic Control and listen for audible CLICK as valve operators open. No CLICK,
replace valve.
3. Check for ignition spark (spark length approximately 1/8"). Since this is a capacitor
discharge system, observe closely when visually checking the spark as it is faint and
thread-like and may be overlooked in bright light.
a. Between Electronic Control high voltage terminal and strip terminal GND. No spark,
defective Electronic Control.
b. Between Electronic Control high voltage terminal and Spark Electrode Wire (insert
head of #8 x 3/4" or longer round head screw into snap terminal inside right angle
rubber boot). No spark, broken wire, cracked insulator, or "spark gap" too wide, see
Figures 7A and 7B.
c. Between spark electrode tip and top of ground rod, see Figures 7A and 7B. If spark
is not visible and/or can not be heard, remove nozzle assembly (see Section IX
Electrodes) and ground it solidly to burner metal. No spark, cracked insulator and
spark traveling to ground along crack.
4. Turn Manual Gas Cock Knob to ON. Connect manometer to the manifold gas
pressure tap and during trial for ignition, check the gas pressure:
a. Pressure should be between 2.0" and 4.0" W.C. for NATURAL and PROPANE and
steady. Verify per Section VII (Main Gas Input Selection) and Table 3 (Capacity and
Preliminary Gas Settings) that the orifice size and manifold pressure are correct.
b. Zero, erratic low or high pressure: confirm that the inlet pressure to the Combination
Valve is between 5" and 14" W.C. for NATURAL and PROPANE during standby and
during trial for ignition.
c. If manifold pressure is zero, below 2.0" or above 4.0" W.C. for NATURAL and
PROPANE or erratic,the regulator section of the Combination Valve is defective and
the entire valve must be replaced.
III A. With motor running check burner line voltage terminals for 120V as follows:
1. Between strip terminals L1 and L2-120V; voltage OK.
2. Between strip terminals L1 and GND-120V: ground OK.
3. Between strip terminals L2 and L2-"0"V: no back-feed, OK
B. Follow RESET procedure as specified in step II.B.
1. Check sense electrode position per Figure 7A or 7B
2. Check sense wire for continuity.
3. Connect DC microameter in series with Electronic Control SENSE terminal and sensor
wire. With flame on, flame signal should be at least 2 microamps.
C. IMPORTANT: If Changes are made in the Main Orifice size, Manifold Gas Pressure or
Primary Air Adjustment, change the installation data tag accordingly.
IV A. Low manifold gas pressure.
B. Main gas orifice too small.
V A. High manifold gas pressure.
B. Main gas orifice too large.
C. Primary air adjustment closed too far.
D. Dirty blower wheel.
VI A. Wutomatic electric (redundant) valve section of Combination Valve is defective and
entire valve must be replaced.
* Normal low voltage:
Motor running-24V minimum.
Combination Valve energized-21V minimum.
** CAUTION: If changes are made in the Main Gas Orifice size, Manifold Gas
Pressure or Primary Air Adjustment, change the installation data tag accordingly.
IV Short
Flame**
V Long Hazy
Flame**
VI Gas Fails to
Shut Off
III Flame on
Only During
6-Second Trial
for Ignition
Part 3
Maintenance Continued
Trouble Chart
Continued
Part 3 Trouble Chart Continued
Midco ® International Inc. 4140 West Victoria Street * Chicago, Illinois 60646 602
tel 773.604.8700 fax 773.604.4070 web www.midco-intl.com email [email protected] 8471 25
Printed in USA