Steam boiler water pulling into mains

Zachspry887

So we replaced a six section peerless boiler at a church with two condensate return tanks one in building one in boiler room last week and have been back on numerous service calls. I arrived on site and found the boiler was tripped on the probe lwco. Ran the boiler it runs fine but when it hits 1 psi on pressuretrol and shuts down after 20-30 seconds water gets pulled out of the boiler into steam piping and trips lwco. I even let system warm up and run for a while so piping was hot. I went through building to check traps and air vents and cleaned a few and replaced a few. Talked to peerless everything is okay for piping besides the fact the makeup water goes into boiler. There is a vaccum breaker on the boiler and I tried installing one on the header but it is still doing it. Do I need an equalizing line or does anyone have any ideas for me?

Paul S_3

All steam boilers need an equalizer. Can you post pics of boiler?

Ironman

How about posting some pics of the boiler and its near piping?

Your description isn’t telling us much.

Jamie Hall

Fundamental questions: did it work before the boiler got replaced? And what got changed/replaced along with the boiler?

Is the water line in the new boiler the same elevation as the water line in the old one?

ethicalpaul

The equalizer won't help you with this. I would suspect incorrect installation of the check valve or it could be something as easy as surging due to oil in the boiler.

It's two-pipe? 1 psi sounds like a lot of pressure

retiredguy

As others have stated, we need pictures of the boiler and piping, and what has changed with the new installation. The problem could be dirty water, incorrect piping or a "BAD" installation. You said, "we replaced the boiler". Who is the "we".

DanHolohan

Are there zone valves?

Zachspry887

Zachspry887

There are zone valves but they are not closing

Zachspry887

I guess the boiler has always been doing it but they old company ran pressuretrol up high to 2.5 psi and come back on at 1 so the boiler basically only shutoff for a few seconds.

ScottSecor

Couple of questions and ideas:

1. Is the header at least twenty four inches above the water line in the boiler?
2. The piping into the cross tee on the equalizer pipe could be an issue. We try to keep the piping (condensate return and feedwater in your case) short, like a street elbow or a sho nipple and an elbow. This prevents water from spraying upwards.
3. Most standard stock condensate pumps are designed to overcome much more than one or two psi. I would suggest a throttling valve on the condensate pump outlet.
4. Any chance the boiler water is still dirty and or oily and yo are getting carryover?
5. Keep the steam pressure as low as possible. Maybe off at 1.5psi and on at .25 psi?
6. It looks like an inverted bucket trap coming off the welded steam main below the zone valve. Has this roughly fifty year old trap been serviced? If this trap is not opening or the piping is clogged, you would have a lot of headaches.