Steam Boiler Short Cycling?

Rizz861

So if I’m to understand what’s been said on here, it would seem that a steam boiler shouldn’t make use of a pressuretrol if it’s sized right and the pipes are correct. I’ve seen a lot of steam boilers that just seem to go on and off fairly quickly. Cut in is usually 0.5 and differentials usually at 1, which from what I’ve read is pretty much where you want it for a residential one pipe steam system. The boilers go off at 1.5 and on at 0.5, back and forth, back and forth. These systems I see doing this typically have #35 vents on mains, sometimes one, sometimes two, and at times none. #11 vents on radiators. I don’t know if that means anything to you guys. Steam systems are a big weakness for me as a younger guys. I’d like to know if there’s anything I can do to stop this short cycling or this is all I can expect because of poor design? I messed around with the differential one time and made the cut out 2-2.5 to see what it would do. It seemed to help a bit, but obviously I don’t want to get anywhere near 5 so as not to mess up the vents. Would there be a different setting to use in a system that is oversized or has poor piping arrangement?

Big Ed_4

Does the short cycle occur at the end of the cycle when the radiators are hot ?

EBEBRATT-Ed

Starting with a hot boiler time how long it takes steam to get to the ends of the mains. You may need more venting.

The problem is not so much the system design but probably an oversized boiler if the system is working as it should. Check the connected EDR of the radiation to the boiler name plate . That will give you your answer