How does a natural gas regulator work

I take apart a natural gas regulator used in gas furnaces. Adjusting is covered. What makes it work is covered.
This video is part of the heating and cooling series of training videos made to accompany my websites: and to pass on what I have learned in many years of service and repair. If you have suggestions or comments they are welcome.
If you are a homeowner looking to repair your own appliance, understand that the voltages can be lethal, the fuels are highly flammable and high pressures are used. Know your limits.



42 thoughts on “How does a natural gas regulator work

  1. I have a question about the diameter of the outlet on the gas meter. It is currently 1" diameter. I will have somewhere above 90' of pipe from the meter to the furthest appliance. Around 300 000 BTU/h. And standard 7" water column on the house side. So I would like to attach a 1.5" pipe to the meter. Can you install a 1.5" diameter pipe outlet on the gas meter with 1" outlet? From my understanding, attaching 1.5" pipe to the 1" outlet on the meter would create a bottle neck right there? Thanks

  2. Do older gas pressure regulators leading to an individual gas appliance (gas fireplace, range, etc.) ever contain mercury? I understand that older gas regulators leading into a home sometimes contain mercury, and would like to know if the pressure regulators for a single appliance can as well. (The specific situation I'm interested in involves a gas fireplace connected to a very old-looking pressure regulator.)

    Here are the articles I've seen that discuss mercury pressure regulators:

    Thank you for any thoughts!

  3. I wonder, what is the maximum inlet pressure these units can handle? I assume the exit pressure is around 7-8 inches of WC?

  4. great job sir

    you explained the regulator as i want and also as other people want

    the way you speak, indicate, zooming in and out is helpful

    thank you buddy

  5. My reg stops completely once there's pressure in the line between it and the control valve. It won't reopen unless you disconnect the line. Bad or broken spring?

  6. How often do the diaphragms wear out. They're pretty much a moving part right. Here in the UK medium pressure regulators are set to work at at max of 75 M/bar. They're designed to govern domestic dwellings at 22 Mb constant. They can only be replaced or adjusted by the energy service providers. What tests can you carry out on multifunction valves ( warm air units ). They're very common in Canada and America right? Is it thermocouple test, solenoid test & working pressure test? What other safety features do warm air and open flue boilers have? I really enjoy your videos. You explain very clearly. How do atmospheric sensing devices operate?🤔

  7. Grayfurnaceman, what could cause a regulator to chatter or flutter. I’m having issues with my manifold pressure fluttering between 3.5 – 5 in wc on Nat gas. I believe it’s at the regulator, bc I can feel it fluttering when the burners are lit. My supply gas pressure is right and the leaving side of the regulator is at 14”, but when the gas valve opens the fluttering starts. Any ideas?

  8. Is this what a landlord would use to manipulate the flow of heat to an apartment. I do not have gas it is a boiler.

  9. These things suck I work for a gas company in my state come across entire neighborhoods where all the regulators are failed any type of reading on the machine is an automatic call in an schedule for repair.

  10. The small hole on the top side of the diaphragm is to control the opening and closing speed of the regulator. Informative video none the less.

  11. My bottle gas was excellent when I bought it …great … I used it for a long time perfect … but now when it is ignated it realeses a smell of petrol as it in use … what is happening ???

  12. would my regulator have anything to do with my furnace starving for gas.  I have been struggling with when my furnace starts up the glow igniter has a hard time igniting a flame and clicks a lot, then when burners finally ignite it may kick off and start over.  I replaced the flame sensor and igniter and still had issues, then the other day my propane tank was filled up with some more gas since I am on a budget plan, and it has been working fine ever since.  now weeks later I started hearing that clicking sound again and furnace isn't igniting right away.

  13. Had gas leak wasn't line it was inside the oven could this peace be the problem. All by releasing pressure from the spring could that stop the leak?

  14. Great video. Thanks for the demo. I just took a test and one of the questions was… Name two purposes of a gas regulator? I obviously know one is to regulate pressure. However stumped on what the second purpose would be. Any help would be appreciated.

  15. Hey do you think a regulator issue could lead to increased consumption. Got my bill and it said I used 50% more than last month, had a regulator replaced because I smelled gas outside. Any thoughts if they're connected?

  16. Isn't there a spring underneath the valve as well? Or is that only with some other types of gas like acetylene?

  17. I'm having a real hard time understanding the "lock up pressure" in relation to this. this video helps but could you clarify for me to make sure I understand properly. thanks for all your video they help a lot.

  18. the diaphragm and shaft part of the regulator reminds me of the old mechanical fuel pumps on cars from the 1950s. some had two lobes one to pump the fuel and one to create a vacuum to run the windshield wipers.

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