Clocking a Gas Meter

 February 9, 2021      Jeff Rosenblum

 

There are times that you may need to clock a gas meter. This is required on a start-up of a new furnace or to verify the input of an existing application. This will verify the incoming BTU’s. It is a very simple procedure and can help in your diagnostics. Here is how you do it, step by step.

  • Make sure all gas appliances are off other than the one you are diagnosing. Even shut off pilot lights, it can affect your reading.
  • Make sure the appliance you are checking is running in high fire (max output)
  • Get a stopwatch (your phone has one)
  • Time the appropriate dial to measure 1 cubic foot (cu ft)
  • The complete formula is Cubic Feet per Hour (CFH) =

3600(seconds per hour) x 1 cu ft

Time required for 1 cu ft

  • Multiply that number by the BTU heat content of 1 cu ft of gas provided by the utility or propane supplier. Natural gas is typically 1050 BTU’s and LP is 2500 BTU’s.

Now, let’s apply this to the field. If it took 44 seconds for the 1 cu ft dial to rotate all the way around, our formula would look like:

3600 x 1 cu ft

44 sec

=81.82 x 1050 BTUs

=85,911 BTUs input

Jeff Rosenblum 
Technical Support
22 Years Industry Experience
Cell (330) 962-2491
[email protected]