Midco RS40 - Manual (Page 9)

XII Electronic Control
?? If the pressure regulator fails to maintain a constant manifold gas pressure within ±0.1"
W.C., and it is confirmed that the inlet gas pressure to the Combination Valve is a steady
14.0" W.C. maximum during standby, and a steady 5.0" W.C. minimum with the flame on,
the regulator portion of the valve is defective and the entire valve must be replaced.
CAUTION: If the Combination Valve has been moved or replaced, soap bubble
test for leaks with the burner running.
CAUTION: If leakage through the valve occurs on standby, as evidenced by the
presence of any flame, the entire valve should be replaced.
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The electronic control is a 24 volt AC, solid state electronic device that automatically ignites
and monitors the main flame. It has an integral high voltage transformer and upon a call
for heat, applies high voltage to the spark electrode and 24 volts to the Combination Valve.
When the flame is proven, the spark is terminated and the burner run continues.
?? If the flame is not proven within 36 seconds or if the proof of flame is lost during the
burner run and is not re-established within 36 seconds, the control will shut off the
Combination Valve and LOCK OUT. To RESET the system, set operating control to OFF or
thermostat below room temperature for at least 30 seconds.
?? If the electronic control is changed, the replacement must be identical to the make and
model number, or it must be an authorized substitute.
WARNING: Explosion hazard. Can cause serious injury or death. This device can
malfunction if it gets wet. Never try to use a device that has been wet-replace it.
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9
Part 2
Service Continued
Part 2 Service
XI Combination Gas Valve
Continued