Steam Issue

scott337

i have a 1 pipe steam that was split to two zones. the actuators are slightly cracked to allow a small passgae of steam. after a thorough cleaning, the air is now out of the radiators and the system is running nicely. no more banging.

however, the boiler is going off on low water when the second zone fires up only. can anyone help solve this?

i was thinking of venting the return line to allow condensate to return quicker.

i look forward to your suggestions. Thanks!

Dale

Venting

Yes, I too think you need main vents. You also need to be sure you have no condensate on the zone valves. You may be trapping condensate on the non opening valve. You seem to have a condensate return problem only on the one side, I guess I would flush that to make sure you don't have a simple blockage. As to the vents, the rad vent should need to vent the rad only not the main. A picture of how your zone valves are installed would help.

Unknown

Or...

Your boiler firing rate is too much for the pipe size of the single zone. If the pipe can't carry all of the steam the boiler is making, it'll push water out the returns to compensate for it.

At the very least, the piping needs to be big enough to carry the steam you make, even if you DON'T use all of the steam.

I don't use zone valves on one-pipe steam systems. You can see why. I prefer one-pipe TRVs.

Noel

scott337

I do think water is being pushed out of the boiler and I have requested the contractor install a drip off the inlet side of the actuators, install a vent on the main line and then clean the heck out of the boiler. We will see what happens.....

Thanks for your suggestions.