TMH on 2 pipe steam

johnnyz

over the summer, i installed a hot water zone off a 2 pipe steam boiler. it is piped with a brazed plate heat exchanger with a 007 and a pressurized zone off that. there was no tapping on the boiler, so the limit went on the suppy side of the circulating line in a tapped tee just before the heat exchanger. the zone circ and the circulating line circulator pull in simultaniously on a call for heat. if the 2nd zone only calls for heat, the boiler is building enough steam to heat the first 2 radiators, if the 4006A is set above 130 degrees. this temperature is true as it was checked with 2 digital therms. aide from the problems in the colder weather, this low of a temperature will not bring on the kick heater under the kitchen cabinet. any higher creates steam in the main zone. it is an old 5 section steam boiler, with 2-3" risers off the rear section. the supply side to the heat exchanger is from a tapping at the same height as the bottom of the gauge glass, off the front section. it returns to the top of the boiler to a line that drops below the water level in the rear section. i don't see how it can be 130 degrees at the gauge glass level and steaming 6" higher. the boiler doesn't surge and the steam appears dry. i'm just about ready to pipe it off the water heater.

Steamhead

How is your heat exhanger

piped to the boiler? Are you sure you're circulating the water thru enough of the boiler to pick up sufficient heat? The connections should be as far apart as possible.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

johnnyz

the supply is off the front section, right side and the return is in the rear section left side. can't get any further than that

Unknown

Your water is only using the front section

It flows through the bottom connections all the way to the front section, then up to the tapping.

The front section isn't exposed to very much fire. The whole outside is cold, and the top isn't as hot as the others because no flue gasses pass across the top like the middle sections.

The rest of the sections have no load on them. The water nearest the fire isn't moving, so it boils.

Sometimes a small circulator can be piped from alternate ends of the boiler and run during the day to keep the boiler water turning over and mixing, and when the water zone calls, the water is all hot in the boiler.

Of course, you could try to run two 60 gallon indirect water heaters with a 30 gpm Everhot from a steam boiler.........

johnnyz

originally the supply was from the bottom of the rear section. it had the same problem so i moved it higher in the boiler and to the front section. the chamber was also replaced and appears too small and sitting all the way foward under the first 2-3 sections