Kees DFG (DIRECT FIRED GAS) MAKE-UP AIR UNITS - Manual (Page 12)

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D. PILOT LIGHTS, BUT FLAME SAFETY
LOCKS OUT AFTER 30 SECONDS
REMEDY
Probable 1. Defective flame rod. Check porcelain for cracks.
Cause: Replace rod if crack is visible.
2. Pilot flame too small. Adjust pilot gas regulator to
increase pilot flame.
3. Defective burner control If micro-amp meter measures
module. 3 milliamps or more to module
and it locks out, replace relay.
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E. PILOT LIGHTS AND FLAME SAFETY
PROVES PILOT, BUT NO MAIN FLAME
REMEDY
Probable 1. Main gas valve shut-off. Open main valve.
Cause:
2. Defective main gas valve. Replace valve.
3. Low gas pressure. Adjust gas pressure as stated
on unit identification plate.
4. Loose wiring. Check wire connections.
5. Deflective burner control Replace module.
module.
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F. UNIT OVER-FIRE (Excessive
Temperature Rise)
REMEDY
Probable 1. Excessive gas pressure. Adjust gas pressure as stated on
Cause: unit identification plate.
2. Loose belts. Adjust belts for 1" deflection.
3. Dirty filters. Remove filters and clean.
4. Excessive external static Adjust motor sheave to increase
pressure. blower RPM (beware of over-
loading motor) or adjust temp.
rise using regulator inside unit.
5. Dirty blower wheel. Clean blower wheel.
6. Foreign matter on intake Remove obstruction.
screen.