Overhead Return

Brian_80

I am having a problem with a unit heater at the end of a steam run. There is a T in the steam supply line before the heater with one pipe entering the heater and the other joining to a T on the heater outlet before the trap. Water is collecting in the pipe before the trap and causing no heat throughout the heater (I guess). Any suggestions. I'm fairly new to the steam game.

JStar

Unit heater

No pressure differene = No steam movement.



Right now, the supply and return of the unit heater are equalized. Steam will not move through it. You need a trap on the supply drip that ties into the return AFTER the unit heater trap. You will also need to install a main vent on the top inlet of the F&T trap for the unit heater, and install it on a piece of pipe that is about 12" high.

JStar

PS

Also...



The strainer is supposed to be on the inlet of the trap. And you need to install check valve on the outlet of the trap, if the condensate is going to be lifted to a return.

Dave in QCA

won't work that way

The way it is piped will not work at all. How long has the heater been in this location? Is it something that has been added in? What pressure does the system operate at? Is steam pressure maintained all of the time? On the outlet of the trap, it appears to go upward. How far does it go up? Which way does the steam main pitch. Is it coming down hill as it approaches the end of the line? Am I correct in assuming this is a 2-pipe system, that is, the radiators have two pipes, one for steam coming in and one for air and condensate going out?



One thing for sure, the heater and the end of the main, both must have separate traps. Details on exactly how it should be piped depends on the answers to the other questions I have asked.

Brian_80

Thanks

I really appreciate the help. I noticed the Y-strainer position was wrong and was intending to change it when/if I got this heater operational.

Brian_80

Piping Info

This heater was added a few years ago and apparently had a similar problem. I believe it was only working before because the trap was shot and was pushing the steam back to the condensate tank where it was billowing out the vent pipe. The boiler is building to 4 lbs. but drops to about 1 to 1-1/2 lbs. before cycling again. The condensate pipe is pushing 3' to a return line that is 18" above the trap outlet. The steam main does have a slight downward pitch towards the heater. Yes, it is a 2-pipe system.



Should I use an F&T trap on the end of the main or just a thermostatic?



Thanks.

Dave in QCA

two f&t traps

You need an F&T trap for the drip at the end of the main and a separate trap for the unit heater. Follow Jstar's instructions, i.e., the y strainer goes on the inlet. You need a swing check on the outlet of both of the traps. Pay attention to the inlet and outlet markings on the traps. JStar instructed you to install a unit heater vent on the extra inlet port of the f&t trap. In addition to the height that he stated, I am going to suggest strongly that it must be a few inches higher than the elevation of the return main that the condensate is being lifted too.



I assume that you have a thermostat that is controlling the fan. If so, such controls usually place a strap mounted thermostat on the outlet piipe of the heater set at 160F, sometimes the inlet, set for 180, to prevent the fan from being operating unless there is steam present.

Brian_80

Thanks

You guys are great.

Brian_80

Works Great

I reconfigured this unit as per your recommendations and it works like a charm. It looks a hell of a lot better now, too.

Dave in QCA

thanks

Thank you for letting us know how it turned out. Feedback is the only pay we get. Can you post a picture too?