Sludge

joe amadio

About 2 years ago I added a hot water zone off an existing steam boiler using a plate heat exchanger. When I did the original job I noticed while making my boiler connections there was an abnormal amount of sludge/scale in the bottom of the boiler. I flushed it out and figured it was because the customer had not performed annual maintenance in a while. I was back to this job last winter for other work and the customer asked if I would check and flush the boiler if needed. It was as if it were never cleaned out. As bad as the year prior. So, last week I get a call that the new hot water zone isnt working. When I got there I found the wye strainer I installed on the feed to the heat exchanger completely blocked and no water feeding it. Again the bottom of the boiler was full of sludge. Now this is about a 6 year old gas New Yorker cast iron steam boiler. It was installed by the customers buddy from work. Although the piping/install is unconventional it seems to work without much issue. The return has been replaced around the entire basement from what I can see. You can see in the pictures I posted that the return does not drop down to the floor but runs on the wall about 2 feet high off the floor then drops down into the tee off the equalizer in a half harted attempt to create a hartford loop. Can something be wrong with the boiler itself? Is the sludge and scale coming back from the mains and or radiators? Is the Header at fault? Would dropping the return to the floor and installing a couple of boiler drains for cleaning catch most of it coming back? Almost like a trap.

Abracadabra

That near boiler piping is probably creating plenty of wet steam that ends up washing lots of crap into the wet returns.

joe amadio

So, do you think by just repiping the header will take care of it or does the return need to be lowered as well?

Dave0176

How is the boiler sized in comparison to the load in EDR. From the pics it looks like a GSA125 or 150?

joe amadio

Never really checked that. The boiler was installed prior to my work. Why,do you think oversizing may be a cause as well?

KC_Jones

If it's too big and piped wrong (which it surely is) that increases steam velocity and sucks more water out of the boiler and into the piping. Steam boilers should be piped to send dry steam out to the system and keep the actual water at the boiler.

In addition to incorrect piping the riser looks undersized for that boiler. If that is a 125 or larger it should have 2 1/2" pipe at a minimum, that looks like 2". Hard to tell for sure in pictures. Most on here would go beyond that.

You are correct about the returns, they are wrong and so is the lack of a Hartford loop. I am surprised they don't have banging with that return setup.

joe amadio

Thanks KC. I will advise.

EBEBRATT-Ed

I would suggest you investigate how much feed water is being added as that is the most likely culprit. Does it have a auto feeder?? In either case I would put a water meter on it.

Larry_52

As KC mentioned the near boiler piping is less than desirable. Fixing it would be the starting place. If you have scale build up to the extend mentioned try a TSP (trim sodium phosphate) clean out. How much water consumption does the owner attest too?

joe amadio

They are oblivious as too water consumption. But I did a pretty good inspection of the system and there doesn't appear to be any abnormal loss of steam. All vents appear to be in working order.

KC_Jones

joe amadio said:

They are oblivious as too water consumption.

That could cost them very dearly in the long run, you should warn them of this.

joe amadio

Now that I think of it in regards to what KC and dave1076 said there have been several radiators removed from the main due to a recent conversion of some rooms to hot water. So yeah besides about 60 feet of main there is only one 20 section 4 tube 15" high radiator one 10 section and one 12 foot piece of cast iron baseboard left. If the boiler is now oversized is there a way to slow down the steam? Perhaps via some slow rated venting on the mains and rads?