New Steam boiler issues

SamG

I am a plumber with 40+ years experience installing boilers but I’m stumped and am asking for help resolving new install issues.

A customer came to me and asked for a price to replace a leaking 25 yr old 88 series Weil McClain steam boiler serving an apt house. He also requested that I reuse a 1 yr old gas Powerflame burner.

I surveyed the apts, counted radiators, and determined that the existing boiler was twice as big as the attached load. I recommended a Smith 19-6, explained to the customer that he might also require a feed water tank with pump if the boiler had low water/flooding issues. I received the project and replaced the boiler.

Just in case I needed to add a feed water tank after the install, I used a 150 lwco/pump control with an electronic feeder and time delay to prevent flooding instead of a 51-2.
The original near boiler piping had the header take-offs between the boiler risers which I corrected in the new installation
Due to potential flooding of the boiler area, I raised the boiler up on blocks. This brought me to 22” from the waterline to header, so I installed drop L risers to increase the height and create drier steam.
My 3” risers and 4” header feed the original 5” header and I corrected the Hartford loop height.

Upon firing the original burner, I discovered that the installed orafice actually supplied less mbh that my new boiler( indirectly confirming the required load). I corrected the firing rate and placed the boiler on line.

The boiler fires with a steady waterline, no surging, however as it steams, the waterline drops until it goes into low water condition. After about 30 seconds the water level rises, the burner fires, and the cycle repeats. After several cycles, it does make pressure.

Now the fun part…. Obviously the short cycling needs to be corrected. Is the boiler water backing out into the wet returns, is the boiler steaming out the water into the system, or am I getting a false water line in the front section?

Adding to the fun is the fact that even under pressure, only half the building is getting hot (directly as divided by the header steam takeoffs). I replaced 4 main air vents and the steam main now gets hot but not pushing steam to the upper floors even after several hours of running.

Are the 2 conditions related? I appreciate all feedback to the attached photos and video..

Thank You

Sam G.


Note****. I can not get video to post. The total cycle from burner firing, to low water condition, to water level rising back up, to burner again firing is 2 1/2 minutes.

Danny Scully

Have we skimmed @SamG ? Also, that equalizer drop looks bushed on the horizontal. Might consider cutting those bushings out and repiping it so the reduction in size is on the vertical. 

SamG

Water line is steady while firing, just drops lower.

It is bushed on the horizontal partway down the drip leg. Why would this cause the boiler to loose water? Drip leg to loop tie in is 2”

Thank You for advice.

SamG

I planned to put in a king valve and blow out return line but neglected to install.

Danny Scully

Well a portion of water, albeit probably small, is definitely pooling at those bushings, but again, did you skim yet @SamG ?

SamG

I had hoped to avoid the usual long timed skimming by adding boiler chemical due to the fact that there are no drains of any type in the boiler room. The non surging waterline had given me hope. I will have to set up some sort of pumping system to get rid of the water.

Any thoughts on only half the building getting warm?

ethicalpaul

Possibly because it’s carrying over some water into the system, 

the waterline isn’t steady if it’s dropping. How long does it take to empty the boiler? Compute the steam production rate and see if it’s losing water faster than that.

There’s no substitute for skimming, never don’t skim a new boiler. You spent a long time working on it, don’t cheap out now. It only takes a couple hours.

how much pressure does it build and how long does it take. It shouldn’t be building any to speak of.

clammy

For the Size of your boiler I’m sure the equilizer should have been 3 inch instead of 2 . Also the original header size should have not been reduced and should have been done in 5 inch . Not cleaning or skimming the boiler is not helping weather there’s a drain or not every new steam boiler needs to be cleaned of oils. Have you checked and ensure that the combustion numbers and burner operational correct and to ensure proper positive pressure in the boiler and proper draft ,has your stack temp been check I would also look at clocking the gas meter .
Have you check the system piping and is this a single or 2 pipe system . If a 2 pipe I would be looking for bad trapsat radiators and or convectors pressurizing dry returns stopping any steam distribution. Check for any loop seals that are not underneath water and finally make sure your main vents if any are venting properly if not replace .
Don’t discount apartment dwellers having shut the supply valves off it happens .
What type of system piping is in place ?
Personally I always flush and clean new boiler to within a inch of there life and still return weeks later to flush wand and skim there’s always crude . Have you made sure that all wet returns are clear . On another note you may have been wise to use both boiler return tappings ,a lot of large boiler show this in the i and o manual if you look closely ,some may not see any advantage to it but I have seen the difference in using both and ending up w a water which was stead after repiping using both return tappings ,there’s a reason they suggest using both tapping and it’s not to cost you more money it because there both needed weather it’s gravity or pumped returns . If the gas meter was not clocked there’s no way of knowing weather or not your getting the rated output of the boiler .
Dirty boilers do not make dry steam they foam and prime and carry over loads of water and condensate and you will never heat a building that way only push wet steam out to the system which does not travel or carry many btus plus it is no good for the steam mains causing bottom pipe grooving and sooner then later cause leaks at fitting joints . There is no way to avoid cleaning a steam boiler ,put a ball valve on the skim port and bring to a boil and open the ball valve a surface blow will toss out a lot of surface oils ,continue a skim till boiler cools drain boiler wand and re fill and do the process over till while surface blow off produce no oil and your sight glass under running full pressure is steadying . I would truely first look at the boiler water conditions before leaping in everything else ,there’s never a short cut for cleaning a new boiler install and unless you figured a lot of hours on cleaning it’s all for free . This is why those in the know charge what’s they do cause they know there never a short cut just a re do
Peace and good luck clammy

clammy

On another note what a shame to see mega press on steam ,dam near breaks my heart espically since there’s no capping out a thread just throw in the garbage . More proof of a conflict of interests ,what the world is coming to even this stuff is throw away what happened to recycle, re use I guess it’s tossed out the window in the name of time and profit and ease for those lacking tools and skill set ,no offense ,to bad in repiping to a proper header size all that expensive garbage will be just that garbage .
Peace and good luck clammy
Ps again I would not waste time looking for issue first and foremost clean the boiler then assess your distribution issues I would think it’s Associated with the boiler not being clean

SamG

Allow me to update some information:
The 3” risers, 4” header, and 2” as per manufacturer specs. Using only 1 return tapping.
I did re-use the existing 5” header. Only lengthened it to correct original takeoffs between risers
I did clock the gas meter and is set as per specs
I do skim new installations, however this job will require a catch basin, pump, and about 50’ of pipe to the nearest drain. (I have never seen a boiler room without a drain or sump pit before)
System is 1 pipe steam.
I replaced 4 main air vents
Just starting to try out megapress when 3” & 4” custom threaded pipe lengths are not readily available. The few I have used so far have been non issues. I also buy unthreaded pipe or in lengths so I can use both ends. All scrap pieces go the the recycling center.

Attached is a piping diagram.

Thank You for advice

ethicalpaul

I know it’s not fun but you can use two Home Depot buckets and run one to the sink while the other one is filling up. 

How long does it take the water level to drop from normal waterline till it triggers the lwco (if I understand that’s what’s happening)?

EBEBRATT-Ed

Skim into a bucket and use a pony pump and a hose to empty the bucket. There is no substitute for not skimming. Reducing the firing rate slightly will steady things a little

SamG

It goes into low water condition about 1 min 45 seconds after burner comes back on. Just as beginning to make some pressure. Total time of cycle is about 2 min 30 seconds.

There is no sink in basement area. I will have to pump across basement into a stack clean out. I’ve done literally hundreds of projects and have never seen this. Didn’t even think to look.

JohnRambo76

I installed my new boiler a few weeks ago and have already skimmed about 6 times. I did some pipe work and the boiler runs excellent with fresh water, about 1/2” to 1” of water movement when making steam but as soon as that oil can be seen in my sight glass(bubbles sticking under surface of dirt in sight glass) the boiler surges and bounces…never tripping lwco or going above sight glass but you can hear the water going into the header. It’ll take as many times as it needs to.

mattmia2

Look at what happens where the mains connect to the returns and make sure your water line is in the right place like @clammy said. someone put that boiler in a pit for a reason.

SamG

All returns are still wet. The water line was not changed significantly.

The boiler is not in a pit. The boiler room is 1 step down from the rest of the basement, without any drain. Water does eventually seep into the floor. I just didn’t want to stand in 6-8” of hot water while skimming.

Every 20 years or so, a job jumps up and bites you in the butt. I guess this was my turn.

Thank You

JUGHNE

I just skimmed a boiler today that had the same problem you have.

It is a baby PB 63-05 compared to yours, but same issue.

Would start to boil/steam and water level drop as water went up into the piping with a little water hammer.

I believe the hammer was the water going up into the steam equalizer connected to the condensate accumulator, which would have had a head of steam in the top half...a little water hammer goes a long ways when you are sitting next to it.

The boiler had the bottom drain out until clear, then filled to steaming.

Shut power off, added water and skimmed a small stream until boiler cool.

Maybe six hours. The water meter showed only 40 gallons to do this.

Fired to steaming again and water stayed in the boiler.

I am fortunate to have floor drain and a small boiler compared to yours.

But then I had the joy of insulating pipe fittings in the boiler room while doing this.

SeanBeans

What is the pressure set to?

SamG

Skimmed and flushed for 2 hrs tonight. I did use the bucket and pony pump set up.
Fired boiler and all mains and loops got hot quickly. The water in sight glass is uglier than when I started but made pressure without feeding or going into low water. I will return in about a week to reflush/skim.

(Customer wanted me to repipe the header with the takeoffs between the risers.)

Thanks for pushing me in the correct direction.

Started another replacement today with almost the identical specs, but there is a floor drain. Won’t make the same miscalculation. Welders coming in tomorrow to connect to 5” risers and header.

JUGHNE

Are you sure the floor drain works? For me, twice, it turned out the drain was very slow or plugged.

In your first picture, is that a long horizontal connection for a Hartford Loop?

SamG

In my list of photos, the 4th photo shows the rear of the boiler with street L into drop for Hartford loop.

I’ve also run into clogged floor drains. Steam boilers tend to be in older buildings. In this case there were none at all.

Thanks for all the advice

ethicalpaul

SamG said:

It goes into low water condition about 1 min 45 seconds after burner comes back on. Just as beginning to make some pressure. Total time of cycle is about 2 min 30 seconds.

So it’s rather oversized then

KC_Jones

I think your skimming way too fast.  Should have taken at least an hour to fill that bucket once, maybe longer.

I was scratching my head when you were talking about no floor drain and making a big deal about it.

Judging by the flow in that picture it looks way too fast.