steam guage

Ren Pavich

I was called out to my neighbors 3 unit apartment building. has a weil mclein boiler steam. The owner of the building has not maintained the boiler in 5 years. the guage on the boiler while firing didn't register any oz of pressure. I took the guage off after it fired and I didn't have any steam at the pig tail. The boiler is control by a mecury type tstat and the high limit was set at 3 oz. Owner claims somebody was jumping out high limit when it was cold to get enough steam to the radiators. My plan was to order new pressure gauge and verify the boiler was building pressure. then check the limit to see if it opens at the right pressures. I manual moved the limit and the boiler shut down. There are aluminum tubing on the riser leting steam out. Also when it was real cold out some radiators didn't get warm. I am thinking the boiler isn't being controlled by the right kind of thermostat and isn't building enough pressure during colder conditions. I had some boiler burner training but this is my first time trying to work on a steam system I would appreciate some feedback on things to look at and some directions thanks Ren

Big Ed_4

Pigtail

First clean or replace the pigtail. They plug up....

nicholas bonham-carter

things to check for steam

put a good 0-3 psi gauge on the same pigtail as the pressuretrol.verify pressure is less than 1.5 psi max. work with owner to reduce this further to 12 oz. lower pressure travels up to the radiators more quickly than high.

check main vents for proper operation. if any doubts, replace with gorton #2's. their price will be recoup in a short period of time by reduced fuel consumption.

check thermostat location, and anticipator and adjust for longer cycles.

check water cleanliness. if any doubts, skimm clean. use no chemicals if possible.

get 2 copies of dans's book here, "the lost art of steam heating", and give 1 to owner, keep the other for yourself. --nbc

Ren Pavich

bought the book

ok will clean the pigtail and adjust the tstat anticipator. how much steam pressure should a system need to heat with is there a rule of thumb? the owner mention that one tenant said 12 oz and if thats the case why would the vaporstat be set at 3 oz unless someone adjusted ??? I order the book and would the vents be on the horizontal line leaving the boiler???

nicholas bonham-carter

vents

there should be a tapping on the main vents, at the end of the dry return, just before dropping down to the wet return, on a parallel flow system. if a counterflow system, then the vents are at the end of the steam main after the last radiator. these have often been plugged up by someone who did not realize how critically important they are for good comfortable, economic, and quiet operation.

it's a good sign that the pressure is already where it should be. that implies early installation by a steam pro, instead of a knucklehead!

forgot to mention the importance of insulation on the mains, not only for economy, but also for good condensate flow control.--nbc

scrook_2

...keeping the code req'd 30psi (2X boiler max rating) too. Also if you need to replace the pigtail, get a brass one, they're less prone to clogging.