Hello, I have a furnace that short cycles.I believe the problem ls with fluctuating natural gas pressures or tempratures that are feeding to my furnace and PILOT system from the local utility company.
Before starting the furnace the pilot is fine.The flame from the pilot splits in 2 flames.One flame heats the tempreture sensor while the other is burning ready to ignite the gas when called for.Try to imagine an "L" shaped flame coming out of the pilot.Each branch of the flame doing its job.

After I start the furnace it lights correctly and burns great.However after 5 to 10 minutes of running I see the flame that heats the temp. Sensor turn upward away from the sensor allowing it to cool down.Then my furnace will shut down for a period until the flame readjust itself to heat the sensor once again(usually a few mins). This cycle will repeat itself over and over.I tried cleaning the pilot & sensor,it wasn't dirty.

Outside on my gas meter I have a "Fischer Governor" piped in "paralell with my domestic diaphram gas meter.I found a small gas leak from the governor.I'm not sure what this "governor does in relation to my gas flow and metering.It is not inline with the supply gas to act as a gas pressure reducer.It parelles the meter

My Gas bill was 12 times the normal amount last month 23 therms used daily as compared to 1.7 last month and 3.2 daily use last year.

Can anyone tell me what is going on with my system? Thank you very much Gary