No pressure from Steam Boiler compared to last year.

barnic

Hello,
Thanks in advance for any ideas you might have. When I started my boiler this season, I noticed that there wasn't the same amount of pressure I saw the previous year. The radiators still get heat though.

Weil Mclein Type EG-40 (125,000 BTU/HR), few years old.
2 Stage Gas Valve & Vaporstat.
Drop header (2 vertical pipes from the boiler too).
I have a 0 to 35oz/in^2 gauge and the lower flow rate stage would kick in when the boiler reached about 9 Oz and would then run about 5 Oz until the burner cycled off. This year I am reading 0 oz on the gauge continuously. Reasons why I believe the gauge is accurate: No noise coming from my gorton No. 2 vent and it breathed/whistled last year and closed. I don't feel any air coming from the Gorton no 2 like I did last year either. I opened the safety release valve and no steam comes out.
I don't see the water level drop much over the course of a week. Perhaps an1/8" of an inch.

Things I have done so far.
Cleaned the boiler out.
Removed the gorton no 2, and determined that it is open. (blew into it)
Removed the other main vent (Barnes .... stainless steel shell) and boiled in vinegar for 15 mins. This opens and closes with the temperature change of the vinegar and rinsing water).
Removed the gauge and blew into it and I can see the needle rise. (Drained the piping system to the gauge, vaporstat).
Clocked the Gas flow and it was roughly 125,000 btu/hr.
Filled the boiler above the top of the boiler and waited 15 mins. No water leaked from the boiler.
Looked outside on cold day and did not see any water vapor coming from chimney.
I see tall blue flames coming from all of the burners.
I went around to all of the supply valves and do not see any water coming from them.
No changes to insulation from last year.

I am not sure if this helps but I had the gas turned off at the boiler and when turned back on it took a few tries for it to start again.

Thanks for your help and any ideas!

ethicalpaul

Based on my experience, I would suspect the Big Mouth of not sealing. Did you see it in situ to see if steam is coming out?

barnic

I didn't look. After heating up in the vinegar, I held it upside down with the vinegar inside. The level seemed to stay the same. I put cold water in, and then the valve opened after about 5 to 10 seconds. Perhaps it is not sealing in situ though? Perhaps the next test would be to remove that vent, and plug the pipe to see if pressure builds up? Thanks for the help.

acwagner

I didn't see it in your write up, but perhaps I overlooked it and you've checked this already. Have you checked your pigtail to see if it's clogged?

barnic

So I removed the main vent from the longer line and plugged it. Ran the boiler for a while and no increase in pressure. Took the plug out, and put the vent back in and then replaced the Gorton with a new vent and still no increase in boiler pressure. (Gorton is actually a No. 1)
A little water came from the Pressure Gauge / Vaporstat / Pressure Troll plumbing system when I drained it. Ran the boiler again and still no increase in pressure. I do think the gauge is accurate because last year I could hear the steam at one of the main vents, and no cannot. Also, can't feel any air at the main vents when beginning to boil.
Filled the boiler again above the top of the boiler and let sit for an hour and 15 mins. No leaks.
When I filled the boiler after originally washing the inside out, it took 5 gallons to get to the proper water level. Does this seem reasonable? I would think that the boiler would take more than this.
Can anyone think of any other reasons why there would be no measurable pressure in the boiler compared to last year? Could the boiler hot surface have soot on it and not be efficient? Its gas and has not been cleaned since installation ( 2 seasons). Water quality? Poor Draft? Anything else? Any methods to check if I have a leak in the piping? Thanks again for the help!