No pressure on gauge

Michael Lavoie

I just replaced my boiler gauge with a 0-7psi gauge, but I never get a reading. I have attached a picture of the gauge. My cut-in and differential are .5psi and 1psi respectively. I spent like $40 on the gauge - it is a Raven. The other thing is that the pipe that feeds the old gauge was completely filled with water (not steam). Is this a problem?

mike8

pressure gauge

Mike - How long did you wait for the gauge to move? I just bought a new gauge today and the needle lightly bounced against the zero stop for quite a while. Steam begins to move as soon as it is created. The return lines were warm before the needle moved past o.1 psi. After 30 minutes of operation, the needle began to climb steadily. When the needle hit 2.5 psi, the burner shut off like it was supposed to due the pressuretrol kicked in. Needle dropped down greadually to around 1.0 psi and the burner kicked on; again, just like it is supposed to. The burned kept cycling on and off via the pressuretrol until the room hit the setting of the thermostat. If you have about 30 minutes, after you turn up the thermostat to start your boiler, just sit and watch the gauge to satisfy your curiosity and observe what happens during that time. You'll even see the water bounce gently in the glass tube of the low water cutoff. The water in the siphon tube, or pigtail, under the pressuretrol/vaporstat, is normal as far as I know. Mine had water also; the result of the steam condensating inside the tube. If your burner cuts out before the thermostat opens due to the room hitting your desired temperature, and the gauge is still at zero, then I say you have a bad gauge. Regards, Mike

jim_110

Mike if you mean the horizontal pipe shown in the photo was full of water, that should not be. The gauge can be piped directly to the boiler block ABOVE THE WATERLINE.If it is installed BELOW THE WATER LINE it must be mounted on a pigtail. I use a pigtail in all applications. Give us a better picture of the gauge location and your controls.

Vermonter

I recently added a 0-1psi gauge next to the 0-30psi gauge that is required on the boiler. It took almost an hour for it to get anywhere near 1psi in the system and most of that time was spent at only a couple ounces of pressure.

Your gauge has a peg to keep it from dropping below zero. Odds are good (50%) that there is a little bit force pushing the needle down below zero a little, just enough to keep it pegged at zero longer than it should be.

Gauges are most accurate in the middle 80% of the scale, if you're only concerned about what's happening in the first 10% then you may be happier with a different gauge.

I like Ashcroft gauges:

http://www.ashcroft.com/whatsnew.cfm?doc_id=785