24v combination gas valve calibration

Unknown

clocking the meter as you describe will tell you how many Cu ft per hour input your unit is seeing. You can adjust the firing rate somewhat by adjusting the pressure to the manifold at the gas valve but as mentioned above any large changes in firing rate can only be achieved by changing the size of the orifices.

Generally most manufacturers input specs are based on the manifold seeing 3.5" WC for nat gas and 11" wc for LP. So on a 100,000 BTUH nat gas furnace if you set your manifold pressure to 3.5" WC and then clocked the meter you SHOULD see close to 100 cu ft per hour input or approximately 100,000 BTUH input. BTUH input will vary according to the actual heat value of your gas. Rule of thumb is 1000 BTU per cu ft but this is usually a little higher and can only be determined by calling the gas company and asking them what the heat content per cu ft of their gas is. This can vary according to the season as well. People rarely do this so don't be surprised if the girl on the other end of the phone line doesn't know what you're talking about, but she should be able to refer you to someone who does.

If you are off a bit on the cu ft input one way or another you can adjust the gas pressure a little to try to bring it into spec. As long as you can get it to fire correctly and burn cleanly afterwards it's not a problem. If it's way far off then it's time to call the mfg tech rep and determine what the problem is and how to correct it. Hope this helps. My guess is you're no crazier than the rest of us.

Or,,,you can do what Tim says! He'll make it even clearer for you. ;)

gassed out

24v combination gas valve calibration

Has anyone ever calibrated a "Replacement" comb. gas valve? By using the cubic foot dial on a gas meter and how many seconds for a revolution will determine the btus of the valve. Guys on my jobsite think I'm crazy.

bob_46

Calibrate

Hi Craz, (wish we had a name) . If you are refering to adjusting manifold pressure no. You adjust the regulator with a gage or manometer. When you clock the meter you are measuring firing rate. You change firing rate by changing orfices in the burner not the valve.

Unknown

You need to get in touch with me for

some good training on gas systems.