Hartford loop above water line

Sheehanplumbing

We inherited a 3 yr old steam boiler on a parallel 1 pipe system( main pitched away from boiler with a wet return). The last few radiators off the main are not heating fully, only first few sections. Boiler is operating on 1.5 psi main with 1 psi differential ( .5 psi). Air vents are all new including main vent. I noticed the other day the Hartford loop is piped in 2” above the water line. Does anyone know before we correct this can this cause the problem we are seeing? Also the main has no insulation on it. We have already took out a few sags in the main due to the chains coming off for whatever reason but it’s pitched ok now. It seems to me the steam is awful tired by the time it gets to the end of the main. Header piping is a good 26” above water line. House is only 3  or 4 b/r probably 2,000 sq ft. Counted up the radiation and boiler is plenty big enough. Any ideas of where to point me?

EBEBRATT-Ed

Yes. If you have dry returns and If the hartford loop is above the water line steam can come down the equalizer across the Hartford loop into the dry returns travel down the dry return and close the air vents. You will have a "double ended feed" won't work well at all.

When the boiler starts to steam see if the returns get hot at the same time as the supply risers.

If you have wet returns then this can't happen. You would get hammering in the Hartford loop if it is too high with wet return

If you have dry returns the steam seems "tired" because its pushing against the supply & trapped air can't get out

ratio

While I can't speak to your particular instance, having a Hartford loop above the water line isn't necessarily a bad thing. Google "Gifford loop" https://heatinghelp.com/assets/Uploads/HPACGiffordLoop.pdf

Big Ed_4

Pipe insulation yes , I recommend , Make sure the main vent on the end of the main are working and properly sized . Then check the vents on the end of the line . Where they added on after the original install and risers properly sized ?,You may have to tweak the size if main vents are good.