Steam boiler blowdown help

[Brybo86]

To start
I have zero experience with steam boilers as we have always had gas forced air in our home.

Sister and brother in law have moved into a house with a fuel oil steam boiler. And we are visiting them for a few days.

I have been researching steam boilers all day.

It is a Burnham Megasteam oil boiler. It looks like a beast.

They had a couple radiators that were not getting hot. I played around with the steam vent and on off screw valves and got them working. Most in the house are adjustable Hoffman steam vents 1-6 setting.

One of the vents was upside down and sounds like there is water in it, it there a way to make it work again? Put it in the oven for awhile and boil the water out?

It is a 2 story house, I have all of the vents on setting 1 on the first floor. On the second floor I set them all to 1 and have now increased the colder radiators to 2. Heat seems relatively consistent between rooms. Upstairs is probably 3-4 degrees cooler than downstairs. Maybe I need to up the 2ND floor vents to 3-4? Although it isn't terrible because mostly just sleeping upstairs and it doesn't need to be so warm.

Anyways my main question is about boiler blow down. And needed maintenance.
Here is the sight glass which I have read should be clear.

As you can see it is really dirty or maybe even full of mud.

Backside
I think I need to open the drain at the bottom of this pic which will drain the boiler.
I have read conflicting info as to this being done with boiler off to simply drain or with boiler on to violently drain and loosen up more gunk.
Also I have read about adding a cleaning solution then operate the boiler without building pressure?

It was a programmable water feeder with a switch on top that says "feed". Not sure how to operate this or when.

What should my procedure step by step to perform the blowdown?

Thx in advance!

 

[Yah-Tah-Hey]

Let a licensed HVAC business have a look at that boiler. If you are going to proceed with tinkering with it, call the local rescue unit first.

 

[SrDriver]

I am a retired HVAC mechanic. Get a licensed company involved and have them service the system and blowdown.

Not something to work on if you don't have the training and experience.

You could end up getting hurt.

 

[Brybo86]

Love how you guys can't even comment on adjusting the steam vents on the radiators... Lame. Thanks for nothing. Bitog is becoming a bunch of wusses.

Nothing I have read said you have to be a licensed professional to drain and fill the boiler. The owners manual describes the procedure, it doesn't say call the repairman?

My washer is leaking. Call the Maytag man. No I would rather open it up and replace the pump myself.

Change oil in a car? Please take your car to jiffy lube. OK.

Change timing belt and water pump? Take it to the dealer? Nah I'd rather do it myself.

Rotate tire on the car? Call a professional, you could get hurt. What if you drop the car on yourself. OK then.

Thx for the above post for absolutely zero help. Do you guys actually fix anything yourselves?

 

[Andrew1972]

Steam is considerably more dangerous then water boiler or forced hot air. If not done correctly it can hurt someone. Also there is a delicate balance. Your questions are pretty basic.

That all being said I'd visit an HVAC forum and see what is up.

 

[dmark]

https://heatinghelp.com/

THIS is where to go especially for steam. The "BITOG" of DIY heating and cooling. Good pictures go join The Wall (forum) and post your questions. A DIY book "The lost Art of Steam Heating" was $25 when I bought it in 2004 after moving into an old gas fired single pipe steam house and saved me several plumber calls. Nothing better than quiet efficient steam.
Shake the water out of the vents and blow into the threads- upright and upside down- air will flow upright but upside down if the needle is closing it will not.
The vents can be cleaned by bringing to a boil in vinegar (1/2hr to 1hr) then rinsing with cold water. Some cheap vents have a plastic I am told and will be destroyed but good vents have a copper float.
Residential steam is low pressure (1-2 lbs) and very safe.
Good luck

http://forum.heatinghelp.com/
http://store.heatinghelp.com/The-Lost-Art-of-Steam-Heating-p/101.htm

 

[JHZR2]

I love steam heat!

This should help you WRT the vents:

http://www.oldhousejournal.com/magazine/2004/nov/care.shtml

Im not sure that setting them at 1 or 2 (out of 10, IIRC) is sufficient. You may want to make the ones furthest away vent a bit more aggressively to prevent heat rise time in legs with more pressure drop.

Any decent local hardware store in a steam area should be able to help. The local true value by my parents (who have steam heat) still has them.

No, there shouldn't be that garbage in the sight glass. I'd want it to be flushed out. I recall when young, we would (at the suggestion of the local boiler maintenance guy) add water, then dump, by the bucket, until the black water flowed clear. I know this is a no-no in hydronic systems, since you want the oxygen to do its duty and then let the water become non/less corrosive. i guess since steam is open to the air, there's no helping that, which is why a clean boiler (less thermal resistance to raise steam, increasing efficiency) is key.

We never did it under temperature/pressure. Boiler had to be off. Also if there is a fill/auto fill, introducing cold domestic water to a hot system is a good way to cause thermal shock and cracking.

 

[Brybo86]

Got the glass out

Cleaned up with CLR

This is a pic of the glass while boiler is running

I'm planning on draining and filling while boiler is running until it runs clear.

 

[Quest]

@ Brybo:

Please don't take most of the replies on this said subject matter the wrong way, for we know you long enough and some senior, experienced posters are looking @ things from a different perspective.

Ultimately, we worry about liability concerns and care/worry about your own safety and well-being.

No need to get upset over this subject matter. Afterall: steam boiler is pressurised and can cause serious burns and injuries if not handled properly.

Take care and play it safe.

Q.

 

[Kawiguy454]

I used to service commercial cooking equipment including 100KW 480 volt electric boilers similar to the one you have there.

You are correct that lower pipe is a drain valve. If it is plumbed solidly into a drain pipe you can do a blowdown relatively safely.

1.) bring it up to full pressure, Turn off the burner, turn off the water supply and CLOSE the supply/return valves going to the house.
2.) Open the drain valve fully and blow the boiler dry.
3.) close the drain, Refill the boiler open the valves and fire it back up.

Over time the mineral content in the boiler will rise and cause scale problems. That is what you see on the sight glass and thers a lot more inside. It's never a bad Idea to blow it down regularly depending on water hardness. Thats why the drain valve is there.

A professional will also open up the access hole and look inside possibly descale/de-lime and replace the cathodic protector (big Zinc bar) as needed.

 

[Kawiguy454]

...BTW at the bottom of the sight glass fitting there is a bleed valve like a brake bleeder facing downward.

You can clean the sight glass by closing the bottom isolation valve then carefully opening the bleeder a couple of times while the boiler is pressurized. Hot water/steam will push from the top of the sight glass down and out the bleeder. And no it wont blow up and kill everybody on the block.

 

[Brybo86]

I have a small piece of pvc piping that i put under the boiler drain that allow the water to flow into the main basement sump drain, it is pretty low so I'm not sure how I could get it into a bucket of some kind

 

[GiveMeAVowel]

Originally Posted By: Quest
@ Brybo:

Please don't take most of the replies on this said subject matter the wrong way, for we know you long enough and some senior, experienced posters are looking @ things from a different perspective.

Ultimately, we worry about liability concerns and care/worry about your own safety and well-being.

No need to get upset over this subject matter. Afterall: steam boiler is pressurised and can cause serious burns and injuries if not handled properly.

Take care and play it safe.

Q.



Exactly. While I doubt that Brybo would attempt to hold anyone giving him advice here liable for their instructions if something went wrong, people have done just that, even on the internet.

 

[Shannow]

I've put a couple of electric ones about that size into a plant to keep an 80 tonne tank of sulfur molten, and even though they are small and look innocuous, will second (third ??) the "Be careful Earnie".

Steam is more effective heat than water because it's got that whole latent heat thing in the phase change...it's got a LOT more scalding power than hot water, plus, they jet will start to flay the cooked skin.

Can't envisage a system without auto blowdown, even running on the most pure water.

Our chemists would chemically clean that sort of thing with a Citric Acid bath. Feedwater would get a little bit of a TSP based additive on the feedwater.

 

[dmark]

You should drain off dirty water when the furnace is not firing if not cold to let the dirt settle down. When making steam dirt rises into the turbulence and dirt water boils more violently. That looks like it was long neglected.
BE ESPECIALLY CAREFUL not to add cold water to a hot furnace or it may crack. When adding water the water needs to boil shortly to rid itself of excess oxygen or Carbolic Acid forms which eats the iron.
BTW: Vents are sized for the volume of air they need to expel when the heat comes on, not for pressure relief. 1-2lbs is ideally where a residential system that is running well would be. Larger vent for the farthest rad, small for the nearest to the furnace so that all rooms heat at nearly the same time.

But get over to The Wall heatinghelp.com where the forum is mostly trade professionals and you will get expert advice or may search and find answers.

 

[GiveMeAVowel]

I'm almost surprised that there isn't some type of water filter in line before the water reaches the boiler to purify it, no sediment no scale, right?

 

[dmark]

Radiators and most everything else in a steam system are iron so rusty water is ongoing.

 

[GiveMeAVowel]

Originally Posted By: dmark
Radiators and most everything else in a steam system are iron so rusty water is ongoing.


Agreed, but why not slow the scaling process down with filters?

 

[Wolf359]

Actually steam is less efficient which is probably why the highest AFUE you'll find is around 82% or so whereas for hot water you'll find that they go to 95% or slightly higher.

Anyway, I have lots of steam boilers and I'd blow those down all the time. The drain valve is pretty low there, normally mine are higher and I have a bucket to catch it all. I normally just blow it down when the boiler is cold, that way you don't end up adding cold water to a hot boiler. Worse would be if you drained out too much water and then added cold water to an empty boiler, I think you'd risk cracking it then. But on yours, the feed button is part of an automatic water feeder so when the low water cut off kicks in, it's supposed to add water to the boiler so in theory you shouldn't run out while draining it. I'd still do it cold though.

You're also missing a tube from the relief valve, in theory if the pressure builds up, it will blow hot water out of that relieve value so you normally want a tube on there that goes to about 6 inches off the ground.

Home Depot also sells new steam vents if the vinegar doesn't clean them out.

Steam is tricky too, you have to make sure that the radiators are pitched right so that the radiator is at an angle so that the water can flow back down the pipe. If it's going the other way, water will pool at one end and when the steam hits it, you'll hear banging. Very common problem.

 

[dmark]

As dirty as that sight glass looks I would not trust your autofeede or low water shutoff. Heatinghelp.com is a good site to find a local steam plumber. Many plumbers do not deal with them often and it is important to have one who really understands steam. Do not assume the plumber who installed it did it correctly.