Measuring Your Gas Pressure with Homemade Manometer


If your flame goes out frequently on your fridge or you fridge isn’t cooling as well on propane as on 120 volts, you may want to test your gas pressure.  If the pressure is too low it could be the case of your problem.  The Dometic 2310 (and I assume most other Dometics) need 11.5 inches of pressure as measured by a manometer.  What is a manometer?




Step 1:  Go to Hardware store and get a 1/8 inch pipe nipple and 4 ft of plastic tubing that fits it tightly. I got the 1.5 inch long nipple. The 1 inch long nipple would allow more clearance to screw it on.


Note: The 1/8 inch is approximately the inside diameter of the pipe nipple. It is a tapered thread, so buy tubing that you can screw the nipple into to form a tight seal.





Step 2:  The gas test plug is between the cover for the electrical connections and the burner box. Remove the cover for the electrical connections to get a wrench on the plug. The fuse near the plug is part of the Snyder Kit.









Step 3.  Turn the gas off at the propane tank before removing the plug. Cover for electrical connections has been removed and a 12 mm wrench fits the plug. Some gas in the line will vent when the plug is removed.












Step 4. Screw in the pipe nipple with attached tubing.  Use pliers to make sure connection is snug.














Step 5.  Make sure the tubing is not kinked. Then make a loop and tape to a yardstick. The yardstick can be taped to the Roadtrek.



Step 6:  Add enough water and a couple of drops of food coloring to fill the bottom of the loop.

















Step 7:  Secure the tubing to the yardstick so you will be able to read the scale.


















Step 8: Turn on the gas at the tank. Measure the level with appliances off.  Write it down.  In this case it reads 17 inches.











Step 9: Light the fridge and note change in level.  Write it down.  Start water heater and/or furnace to see the effect on gas pressure.  In this case it is 11 inches.


Step 10:  Figure the pressure.  In this case 17-11 is 6 inches.  Then multiply 6 x 2 to get 12 inches.  (You are measuring the distance between the levels at each side of the loop - so it is double the change on one side).


Step 11:  Adjust the regulator on the propane tank to get 11.5 inches.  In this case the 12 inches was slightly above the 11.5 required. We did not adjust the regulator on the propane tank.