Help with purging gas line


  #1  
Old 10-31-17, 04:18 AM
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Help with purging gas line

I needed to move around some of the natural gas lines in my home. One of the things that I did was to replace about a 12 foot long section of 3/4 inch black pipe that feeds by boiler.

For some reason I cannot get the pilot light relit.

There is gas flowing through to my stove and my gas clothes dryer. They are working perfectly fine.

But for some reason I cannot get gas to go to the boiler. Now I understand that it needs to have the air purged out of it since I've done this before (took about 3-4 minutes of purging).

This time though, I must have held down the red pilot button (with the dial on pilot) on the gas valve for about 10 minutes. You can hear the air coming through, but no gas. There is no gas smell at all. Because of this, I cannot get the pilot light lit.

Should it take longer to purge since it's about 12 feet length of 3/4 black pipe?

Any other suggestions??? Everything else in the house is working perfectly.
 
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Old 10-31-17, 07:13 AM
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I haven't done the math, but think about the flow rate of the pilot compared to the volume of the 3/4" pipe. There may be shortcuts that your gas company would be able to do, but unsafe for a DIYer. The gas company should be glad to help, but if they notice any work that does not comply with their standards, they will likely shut off your service until the issues are corrected.
 
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Old 10-31-17, 07:47 AM
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Yeah, the flow rate of the gas valve is very small. Compared to the large diameter of the pipe.

May have to sit there holding in the red button for a long time
 
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Old 10-31-17, 01:18 PM
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There should be an adjustment on the fuel valve to increase the flow rate to the pilot (and, thus the size of the pilot). The adjustment is likely under a cap screw. Temporarily turn up the flow to the pilot. Once you get the line purged, readjust the pilot size.
 
 

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