Service manual

34
Error Message
Description
DHW Sensor Open
The control will not operate the burner.
Test the DHW sensor and related wiring. The error message will clear
once the error condition is corrected and a button is pressed.
Flame Proof Error
Flame was not proved within 120 seconds of Demand 1
10 OPERATION
The MicoFlame Grande appliance should be
installed and started up by factory qualified
personnel.
10.1 START-UP
Gas appliances are rated based on sea level
operation with no adjustment required at
elevations up to 2000 ft. At elevations above
2000 ft the input rating must be reduced by 4%
for each additional 1000 ft elevation. Never
increase the input of the appliance above that
for which it is rated.
Pilot Pressure Setting
The pilot was preset at the factory. The following
description is for the benefit of the start-up
technician should minor adjustment be required.
The pilot burner is controlled by a separate pilot
valve. Pilot pressure setting is as shown in Table
9. A view port is provided on the appliance’s
return end to view the pilot and the main
burners. If adjustment is necessary the following
steps must be followed: Remove the lower front
jacket panel; Remove the ⅛” plug from the
elbow pressure tap and connect a manometer;
Remove regulator adjustment screw cap from
the pilot valve; Rotate the regulator adjustment
screw clockwise to increase the manifold
pressure or counterclockwise to decrease it;
Once satisfied replace the regulator adjustment
screw cap and the elbow pressure tap plug.
Table 11 – Gas pressures at inlet to pilot
PROPANE NATURAL
GAS
Minimum (inches W.C.) 3.9 1.3
Maximum (inches W.C.) 9.3 3.5
Pilot Flame Rectification Setting
The pilot flame rectification was preset at the
factory. The following description is for the
benefit of the start-up technician should minor
adjustment be required. Set pilot to obtain best
µA reading from flame rectification. Minimum
average signal of 1.5 µA is required. If required,
test the signal using a DC µA meter following
this procedure for Honeywell S8600 ignition
module: Disconnect ground wire at appliance
transformer; Disconnect the 24V power and
ground wires from all S8600 ignition modules
not being tested; Set meter to µA DC: Connect
one of the meter’s terminals to the burner
ground terminal on the S8600 and the other
terminal to the burner ground wire; Pilot running
without main burner will generate 1.5 µA
average for best operation. With main burner
running, the signal will be in a range of 4.0 to 7.0
µA.
Gas Pressure Setting
The adjustable ratio gas valve pressure
regulator was preset at the factory. The following
description is for the benefit of the start-up
technician should minor adjustment be required.
Optimum results are obtained when the CO
2
levels shown in Table 10 are obtained. After light
off allow the burner to reach full fire and then
adjust combustion using the high fire adjustment
screw. Bring the appliance to low fire and set the
CO
2
using the low fire adjustment. If adjustment
is necessary the following steps must be
followed (please refer to Figure 27): Remove the
lower front jacket panel; Remove the ⅛” plug
from the elbow pressure tap and connect a
manometer.