Opinion for steam boiler

Steamthemean

Hello all. I was recently in a customers house, his issue was the boiler would run for 50 seconds and go off on low water. Than the water would return after 10 seconds and fire up again. Now I am suspecting a partially clogged wet return causing water to return slowly to the boiler. If you were to feed a gallon or two into the system it would not short cycle, however you will see LWCO light flicker as the water bounces slightly but wouldn’t be enough to cut out the burners. This boiler is two years old. He is Also has a leak somewhere in the system as the VXT read’s 425 gallons, which is insane amount of water being feed. Pressuretrol is cranked all the way down of course. His basement is mostly finished and can not see all of the return piping but I did see all the radiator’s and checked the main for any residue water marks. Found none. What can I do to better track the leak down besides cutting holes in his basement walls to see the return. And could I blow out his returns to get the partial clog out. Thank you for your help!

Jamie Hall

Hmm... it only runs 50 seconds before going off on low water? While it may have a slow return problem, that's not enough time. Even if it's a big boiler -- say100,000 BTUh -- 50 seconds is less than a gallon of water converted to steam. There should be a lot more margin than that.

So...

Could we have some photos of the near boiler piping? Enough so we can really see how it's piped?

Not, mind you, that flushing out the wet returns isn't a bad idea -- it never hurts. But don't bother with steam mains or dry returns.

As you say, that amount of water being fed is just a wee tad high. In fact, by about 20 times for a boiler that age, assuming the counter was set to zero when new. You really need to find out where the water is going -- and I wouldn't overlook the possibility of a problem with the boiler itself. And, of course -- are there any buried wet returns?

JUGHNE

When off and cooled down is the boiler overfilled?
Wet return coming up out of the floor near the boiler?

Steamthemean

Steamthemean

No buried wet returns. It does not overfill when cooled off which points away from slow return.

delcrossv

That's an awful lot of water usage. Is this a new problem or going on since the boiler was installed?

Just thinking out loud, but could it be water getting shot up into the mains , then flowing back? Looks counterflow near the boiler and everything is getting squeezed into the one small supply riser. High velocity/low pressure there- like the venturi on a carburetor.

EBEBRATT-Ed

The header may be too small in addition you have 3 steam mains that should have been brought down to the header seperetly

Steamthemean

EBEBRATT-Ed said:

The header may be too small in addition you have 3 steam mains that should have been brought down to the header seperetly

Right, this was installed by the company I work for. I am trying to change how they evaluate boiler installation. I would have came in with a drop header and as you said piped out to the mains individually from the header. All of this is two inch. I would have came our with two-two and a half inch risers to a three inch header. And line sized out to the mains. They have a very nasty habit of not cranking the pressure down as they always come set very high from the factory.

Steamthemean

delcrossv said:

That's an awful lot of water usage. Is this a new problem or going on since the boiler was installed?

Just thinking out loud, but could it be water getting shot up into the mains , then flowing back? Looks counterflow near the boiler and everything is getting squeezed into the one small supply riser. High velocity/low pressure there- like the venturi on a carburetor.

This is a one pipe Parallel flow system. It does doesn’t it. New problem. Started last week. I will not rest till this issue is resolved:D

The Steam Whisperer

Probably a couple of issues. 1) 2 inch piping is too small for that boiler, 2) If a lot of fresh water is being added to the system, when the boiler runs distilled water is sent out into the system and all the impurities get left in the boiler. The impurities will build up and the water will no longer boil properly. A couple of good flushings out and replace with fresh water will often clear up the problem.
Definitely fix the leaks and cleanout the boiler with some boiler treatment to remove the scale and sludge build up.