Hole in the boiler

Jeff_44

I have a one pipe system with a relatively new boiler (six years). I have had some issues as of late with uneven venting in the mains (and many of you helped me think this through on another post) and also sometimes, a random radiator doesn't get any heat.



The 0 - 30 gage on the boiler used to show pressure when the boiler was firing. Now it's frozen on about the '1-ish' lbs mark. I bought a new gage at a local supply house - the best they had was a 0 -15. When I installed it in place of the old one, the new gage didn't read any pressure at all. Then I put a T type configuration with the pressuretrol and new 0 -15 gage atop the pigtail. And when I fired up the boiler it didn't show pressure reading. I took the gage off and water/steam bubbled out and I could hear a gurgling sound.



I then tried an experiment. I closed all the radiator valves in the house, fired up the boiler and let it run until the both sets of main vents shut. And even with no radiator load and the mains full of steam, the gage still did not register any pressure.



I'm wondering if the inability to build measurable pressure on the gage or pressuretrol could indicate a hole in the boiler above the water line. Or do I need a gage that reads 0 - 3 lbs. Any thoughts?

nicholas bonham-carter

leak detection

can you see excessive steam coming out of your chimney?

the other method of detecting a leak is to over-fill the boiler, well above the top and watch for signs of a leak over a period of a few hours.

even that 0-15 psi gauge is not very sensitive at seeing the low pressures needed for steam. i suggest, a 0-3 psi, from the gaugestore .com.--nbc 

Jamie Hall

Couple of thoughts...

in addition to Nicholas' remarks... first off, code requires you to have a pressure gauge reading to twice whatever your pressure relief valve is set at.  That's commonly 15 psi, so no matter how silly you may think it you need a 0 - 30 psi gauge on the boiler.  You can mount it, though, on a pigtail and T arrangement with a nice 0 - 3 gauge, which is actually useful.



Second, have you been tracking your makeup water usage?  Because another really simple way in which a hole in the boiler will show up is in using excessive (hard to define, but your boiler manual will have an upper limit -- and believe me, it is an upper limit (for reference, the boiler in the system I supervise uses about half a gallon a month in makeup, in addition to what is made up when I blow down the LWCO)) water.  Something to look at...

Jeff_44

Thanks

I will shut off the auto make up valve for a few hours and check the site glass to see if the water level changes (I've marked the current level with a piece of masking tape). Do I see a lot of steam coming from the chimney? Not really, but I seem to notice little more white exhaust then I used to. When the outside temp is really low, I can see white exhaust, but on warmer days I generally see only heat waves. Today, it's in the upper 20's and I could see some white exhaust. Don't really know if that's steam of if it's cold enough 'see' the exhaust instead of heat waves. I'll get a three lbs gage and see how it reads.



Thanks

Jeff_44

Pig Tail?

Is the pigtail on the pressuretrol supposed to be filled with water all the time or does it fill as the boiler fires up? On the last boiler cycle, I removed the gage off the T that also holds the pressuretrol - it wasn't very hot (although the boiler was) and I could blow air into EL that holds the gage and there was not water in the pigtail.

Jamie Hall

It is best

when reinstalling a pig tail to "prime" it -- fill it with water.  With time, though, it will fill.  Takes a lot of time.