What did they do?

Alex265

I posted this in the Pressure thread, but probably shouldn't have clogged that thread, so I'll open a new one. My steam system changed the pressure on which it operates during the cycle after two events. I have a 0-3 PSI gauge, which I spent a lot of cold mornings in the basement watching during the last season.



Before: the pressure would stay on about 5 oz. after the steam is ready to go, and would gradually go up to 8 oz. after 30-35 minutes and then thermostat is usually satisfied, so vaporstat never trips. The water in the glass was clear but somewhat brownish, and its level would go down from 3/4 to 1/2 of the glass and would move noticeably around the 1/2 mark when the steam is being produced. Radiators are warm within 20-25 minutes of cold start. I always could here the main vents hissing when the first portion of steam goes out, and the radiator vents hissing after that (not loud but audible, kind of liked that sound).



After: the pressure stays around 1.0 oz during the whole 30-35 minutes, with a very small build up to 1.5 oz. towards the end of the cycle. The water in the glass is clear and clean, much lighter than before. Instead of going down when the water boils, it goes just a little up, and does not move much. I can't hear ANY hissing from the vents, main or radiator vents, but the radiators are still warm within 20-25 minutes of cold star - this did not change.



What happened:



1) the guys changed the chimney liner system for the boiler/water heater flue;

2) while doing this they flooded the boiler.



When I came home, the 0-3 PSI pressure gauge was showing about 1.5 PSI and the glass was full of water. I started draining the boiler and pretty soon the water level in the glass returned to normal, and the pressure gauge returned to 0. I think I drained several quarts of water, so it wasn't too much of a flooding, I guess.



But after this two events the behavior changed. I thought the gauge went south, but this does not seem the case. I also disassembled and cleaned the pig tail and all the orifices that carry the gauge and the vaporstat. Because I can't hear the vents hissing anymore - I think the pressure that the gauge shows is real. All the radiators are warm within the same time as before, the system seems to work not any worth. I'm just trying to understand what can cause this change in behavior, whether something broke or is it normal.

The Steam Whisperer (Formerly Boilerpro)

Probably....

your water was getting dirty and when they flooded the boiler and you drained it some of the excess impurities were cleaned out.  An engineer I installed a boiler for several years ago would gage when the boiler needed cleaning, by how much the pressure it would build on a typical cycle.  When pressure started to rise, he knew the boiler needed cleaning.