Jump to content

Water hammering in steam heat system

Rate this topic


Rich / In2Bass

Recommended Posts

I have a gas steam heat system by Crown (Jamacia II) that's been giving me a problem. I have had the system for about 16 years (with no problems) and the boiler seems to be buliding up water which is creating the water hammering. I drained it where the water level is half way down the water line in the glass tube where the system runs nice but the what builds up after the furnace runs. I know the valve for the water feed is ok where water is not feeding in the system.

 

I can't figure this out ... is the steam not escaping which is causing the constant water build up?

 

Thanks for any input.

 

Rich

Link to comment
Share on other sites

We need to start with a good cleaning. Signs of needing a thorough cleaning are surging in the glass. A thorough cleaning involves putting in a cleaning solution from the top of the boiler or the side of a boiler by removing the T and P valve: running a cycle, turning it off and draining after it cools. All controls must be removed and inspected, including pigtails for your pressure switch ,T and P relief valve, sensor etc. Replace the T and p, every 3 years. Cheap insurance.

 

Below are diagrams of a one pipe steam system and a two pipe steam system to trouble shoot. It will show the wet return. Both will have a hartford loop on the wet return going back to your boiler. There should be draws off on the wet return for service. This allows for cleaning and to take out the dirty water. Sometimes the return gets plugged up and you will get a slow condensate return that sometimes overfills the boiler after a heating cycle. Just last week I had to run a snake up into a return because the home owner never had his boiler cleaned.

 

Trapped water is the enemy in a steam heating system. Whether it was from overfilling or other. If hangers were removed this will changed the pitch of the pipe and may cause water to trap. If fitting reducers were used to reduce pipe due to renovations, these reducers must be "Eccentric" type and not "Concentric" type. This will allow condensate to return without trapping.

 

 

This will be enough to get started. Maybe someone else will chime in with something.

 

 

[img=

 

p><p>  <a href=http://www.stripersonline.com/image/id/2660605/width/600/height/600' alt='600'>

 

 

 

 

 

 

Link to comment
Share on other sites

Riddler,

 

Thanks for the reply ... not sure if I can do this myself but I guess I can try cleaning it out first with a cleaning solution. What should I use?

 

It looks like I have a one steam pipe system according to your diagram.

 

Here a picture ...

 

[img=

 

http://www.stripersonline.com/image/id/2661376/width/600/height/450]

 

 

Link to comment
Share on other sites

That is a cardinal sin! Copper on a steam boiler and it's above the water line to boot. It's not against most codes that you can't use Copper but many of us in the trade do not use copper on steam because of the expansion and contraction and also because of corrosion from the return water. Most manufacturers want swing joints off the headers 20"-30" above the water, and the only way to get swing joints is with IPS threaded connection not sweat.

 

What you need to do is to make sure the copper is not pitted and leaking steam above the water line. Sometimes the vapor escape from copper is so hard to see you have to put a drop light down and look for vapor. Looking at the photo I see some corrosion on the copper. The return condensation has a higher PH level and loves to rot out copper and form pin holes. These holes can be micro but will allow steam to pass through. You should only be filling your boiler maybe once a month in a tight system. If you are filling daily or weekly, you have to find the source of the leak or leaks. The leak could be off the supply header, or possibly up near a radiator. Constantly replenishing with oxygenated water, will rot our your cast iron boiler prematurely.

 

Right by the Hartford Loop there should have been one more draw off to clean that out. A Tee with a draw off instead of another elbow would have worked. The Hartford Loop connection to that Tee fitting should be 2" below the water line of the boiler and the shortest piece of pipe in between the Tee and the copper elbow to do the hartford loop correct. In black iron we make that connection with a "close" nipple. See the diagram on how to pipe a hartford loop and the dimensions:

 

216

 

 

 

 

 

I think you can handle the cleaning of the boiler. The water in the glass looks brown from the photo. Try " Hercules Scout". Back off the T and P off the top of the boiler, use a funnel and pour the powder in. 1 1/2 cans should do it. Follow the instructions and run a cycle. No need to drain Scout. Taking all the controls off for cleaning requires some work, you may wish to opt out of that. But I would replace the T and P no matter what. Right down the information on the T and P tag and buy it at the supply house with the Scout. 30 bucks for safety is worth it. Seal all threaded connections with teflon tape and pipe dope. For a quick cleaning, takes you less then 10 minutes to remove t and p and pour the powder in, reseal the boiler and start it back up. To strip it down it will take you 2 hours to do the job 3 if it's real dirty. I'll get $400-500 plus parts in Boston to do a total cleaning.

 

 

 

If the copper needs to be replaced have it done in Black Iron, with unions off the headers to make replacing a boiler easier in the future. Rough ball park to replace the copper and turn it into black iron would be roughly $1200-$1400.

 

 

 

 

 

 

 

 

 

Link to comment
Share on other sites

Some good advice there from Riddler. If you remove the pigtail for cleaning make sure you orient it back the same way, otherwise its expansion can throw off the pressure switch above it. I'm not a big steam guy, but I know in older homes, clogged/slow return lines often trick the boiler into overfilling.Returns can be cleaned with chemicals.Skimming(cleaning) the boiler as mentioned is your least invasive/expensive option. Check the pitch(non pipe side should be raised slightly)of your radiators, and the vents on them. Floor settling can back pitch rads, and vents must be unclogged. One other rare overfilling problem comes from internal cracks and splits. This can be seen as heavy steam comming out of the chimney.If you seek help get a steam expert! Good luck.

Tis better to remain silent and thought the fool, than to speak and remove all doubt.

Link to comment
Share on other sites

Yap, give it a shot. TSP is the usual ingredient. Glad you are not filling the boiler often. Hopefully a good cleaning solves the problem. If not we will try to look at other things. Cheech or someone here may also have input on it. Clean once a year though, it's easy to do.

 

 

 

Link to comment
Share on other sites

This is from Hercules website:

 

1) Turn off heating unit. Close off zoning as described above. Pour

first dose (See Quantity Table) into top opening (valve or plug). Fill

with water to operating level. Replace valve or plug on top of boiler

with an elbow with a piece of rubber hose attached. Place end of

hose in metal receptacle. 2) Fire boiler and raise water level until

steam and/or water flush oil and floating contaminants away through

hose.When water runs clear, shut off water and heat source and

remove hose. BE CAREFUL OF ESCAPING HOT WATER AND

STEAM. 3) Drain boiler water, if necessary, to operating level. Add

second dose of boiler & heating system cleaner. Replace elbow

and hose with original valve or plug. Reopen circuit valving. Fire

boiler to normal pressure and allow to operate one week. 4) After a

week, cut off heat and let boiler cool; open bottom drain-off valve and

drain to remove heavy sediment. 5) Clean all drain-cocks, gauges,

gauge glasses, valves and replace. 6) Refill boiler. Add another dose

of boiler & heating system cleaner and allow to remain in boiler.

 

 

 

Link to comment
Share on other sites


    If the water feeder is automatic, shut its valve for a run cycle while you are present and can check the sight glass. If its a manual feed, make sure the valve is holding. A worn out steam trap on the return piping may not be separating the steam from the  water, and allowing hot steam to re-enter the boiler.  I realize its a bouncing /overfilling issue, but sometimes water loss can be the culprit. If ther is a oily residue in the sight glass, or scale from well water, skimming (cleaning) may be the fix.


Tis better to remain silent and thought the fool, than to speak and remove all doubt.

Link to comment
Share on other sites

I had this problem last year...my boiler kept adding water when water wasn't actually required, creating a really full boiler.

A guy came out and said the sensor on my auto water feeder was bad. He wanted $500 to replace the part w/ labor.

 

My zero dollar solution: Close the valve which feeds water to the boiler through the automatic water feeder. I look at it once a week to make sure there is enough water per the site glass. It's been running for over a month this heating season and I haven't had to add water yet.

 

Close the water valve which connects to you auto water feeder and see if that stops the problem.

"Where is my mind?  Waaaaay out in the water see it swimming?"
Link to comment
Share on other sites

It is a manual feed and the valve is holding.

Where would the steam trap be in the pic's that I posted.

Not sure how to skim it as well (where to drain from??)

 

If you have a one pipe system you would not have steam traps. Steam traps can be found near the radiator or sometimes underneath.

 

264

 

Skimming directions were posted above from Hercules website based on the product you bought.

 

 

 

 

 

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to register here in order to participate.

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×
×
  • Create New...