steam boiler short cycling

Dave_22

A friend recently bought a house with steam heat. When I went down to watch it, it short cycled constantly on the low water cutout switch. I'm not too familiar with a steam system-any ideas??? It's a one pipe system and the boiler was replaced 4 years ago. Thanks.

ed wallace

steam heat short cycling

what is pressuretrol set at? is it gas or oil? is it the right size for the house

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Dave_22

not sure about the pressuretrol. It is gas and I have not done a heatloss so I am not sure about the load. Looking at the gauge,if it works, showed under 1 psi.

Fred Harwood

short cycling

on the LWCO may have little to do with more than adding a bit of water. After the boiler has been off for 10 minutes or so, where is the water level? Still near the CO?

Mad Dog_2

Yep, or could be

a dirty boiler too. Mad Dog

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Dave_22

no- it seems almost as soon as the burner shuts off it comes up midway on the site glass.

Scott Kneeland

are the returns dry or wet? if wet they may be plugged and slow to return. Causing the cycle of low water

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Dave_22

OK- Now I am at the point of being confused!!! What is dry or wet returns??

Scott Kneeland

Dry returns are returns that are above the water line, wet are below it and full of condensate all the time. Wet are sometimes under the floor or on the floor.

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dwk

short cycle-steam

Check your pig-tail it maybe plugged which will cause short cycling.

Dave_22

not sure if it had a pig-tail, it been a few months since I looked at it. I think I need to study steam heating a bit more!!!!

WPH2205

Dave, it sounds to me like a near-boiler piping problem. If the boiler is not piped properly with a correctly sized header, equalizer, and Hartford loop, when the boiler makes steam, the water will back out the bottom of the boiler and into the returns. this will cause the water in the glass to drop and the boiler to go off on a low water condition. When the burner shuts off and the pressure goes down, the water comes back in and the burner turns on again. Check the piping. Also I agree with the post above- it could also be a dirty boiler. May have to be skimmed and cleaned. But I don't think it's the pigtail on the pressuretrol. My experience with these is when they block up, the burner will run until it gets steam up, then shut off and not come back on. Good luck.

Dave_22

Thank you all for your help. I will take these thoughts with me when I go to have a look. Also, thanks for your patience in helping me understand steam a bit more!!!