A.O. Smith FPS 75 Technical Information page 39

FPS/FPSE/FPD TECHNICAL TRAINING AND SERVICE WORKBOOK
FPS 40 and 50 SERVICE AND OPERATION cont
PILOT PROBLEMS Trouble-
shooting cont.
The following are possible causes of pilot problems:
1. Incorrect pilot position; the pilot should engulf the tip of the
thermocouple 3\8" to 1\2",
2. Incorrect thermocouple output; it should generate 7 or more millivolts
when pilot is burning.
3. Incorrect pilot gas pressure; it should be 3.5" for natural gas and 10"
for propane.
4. Excessive equivalent foot length on vents can cause pilot outages
5. Backdraft can cause pilot outages. (See page 16)
6. An open E.C.O. will not allow the heater to be relit.
7. A leak in the pilot tube will cause candling.
Technical Information
Irvin.CI. Texas
38
@1995
A.D. Smith
Water Products Co.