No pressure

rcrit

I just received and installed a new 0-3PSI gauge from gaugestore.com.



My 0-30 gauge was installed on a 90 coming off my pressuretrol. I took off the 90 and replaced it with a T. On top of the T I installed the new gauge and on the other end added a 4" nipple and put the 90 with the 0-30 on the end of that.



Then I fired up my boiler.



The most I saw on the new gauge was a little bit of bouncing. It never even got up to .5 PSI. Should I assume my pigtail is clogged? How dangerous is this (e.g. should I drop everything and run back downstairs to clear it?)



It currently looks something like this crude drawing:



                     0-3      0-30

----------          O       O

| ptrol  |--------+------+

----------



As a follow-up, how tight does this need to be? I don't want to over do it and end up damaging the brass. Things are on pretty tight now though I'll bet I could get another revolution if I put some real elbow grease into it.

BobC

Plugged

if the gauge is bouncing it it is probably seeing the boiler pressure. If you want to be sure you could remove the 0-3PSI and blow into that open pipe, you should get a little resistance but you would know if it were plugged. the pigtail should be tight but don't go crazy, you don't want to bust off the pigtail, as long as you use teflon tape or pipe dope you should be fine. The gauge should be vertical as it is in my photo.



You may just be operating at very low pressure, especially on a mild day. You could try boosting the thermostat 4-5 degrees to make the boiler run for a while.



Bob

David Nadle

Did you see 0.4 PSI, or did you flutter about zero?

0.5 psi is 8 oz/in^2. That's a cut-out pressure for many systems, and it's possible yours wouldn't reach it for half an hour or more. The needle will flutter, but if you saw the average needle position gradually increasing and remaining above zero then all is probably well. A 0-30 oz/in^2 gauge would give you more resolution.

rcrit

fluttered

It fluttered around zero.



The first time the boiler fired up it did what seemed like a normal cycle. At most the gauge fluttered a bit to the first line, so 0.1 PSI.



I went upstairs and cranked the tstat to 80 and watched for a while. The boiler fired constantly for what felt like several minutes. I heard the Hoffman clunk open and closed twice. The whole time the needle fluttered right above zero. Needing to return to work I reset the tstat and posted here.



I'll try to keep an eye on it this evening. My vents really whistle at times so I figured my pressure would be a high if anything.

David Nadle

Check the pigtail

Your gauges and control might not be seeing the pressure. Check the pigtail.

jpf321

a correctly sized boiler...

probably won't get any pressure built for at least 35-60mins. "several minutes" won't cut it.