Close to perfect BUT...bangggg

Mark_134

Convert from oil to gas, of 100 yr old small colonial, 25' x 36', 7 current radiators (2 radiators removed decades ago) last month. Reputable local installed Burnham IN5 w/ electronic ignition, new auto feed, new Crown Megastor water heater (indirect). Issues with loud radiators, not enough pitch, and banging. Steam guru addressed with new vents, better pitch, alas quieter radiators - kids now aren't waking up at 4am. Yet, as the cycle near ends, radiators hot, vents doing their thing, there is a period of 3 minutes where extremely loud banging of pipes - from the second floor - seem to be heard coming from under the floor- not from radiators which are alongside the walls. The banging is extrremely loud. It's taken numerous readings (this is the great site!!) to address the various nuances to this new system. We are alomst there, as we enjoy a quiet home. This last burst of banging has us all up early and perplexed. What should I look for, to, and who is best to take a look at it?        

EBEBRATT-Ed

just a thought

Just a thought. If some radiators were pitched up on the far end to make them drain back toward the supply (which is correct with a 1 pipe system). Could they have been pitched too much causing the supply pipe under the floor to have a low spot ?

You may have to raise the radiator on both ends slightly and then raise the far end.

Rod

Water Hammer Problems

Hi- Sorry to hear you're having problems. Can you determine where the banging is located on the system? It would help a lot if you could post some pictures of your boiler and attached piping, particularly pictures of the equalizer. Did they use an elbow and a close nipple to attach the wet return to the equalizer pipe?

- Rod

BobC

Hammer

If you have not seen this it's worth a read -



http://www.heatinghelp.com/article/347/Water-Hammer/287/Water-Hammer-in-Steam-Heating-Systems



Bob

Mark_134

Possible

I asked if I can or did I pitch the far end too much (1/2-inch) to which he said no. But I think taking it down a bit may help. Why raise the radiator on both ends then raise the  far end - doesn't that accomplsih the same pitch?  

icesailor

A Rub:

Here is a possible "rub" to your problem

I find this in every building I go in. The middle of the house framing will shrink more than the ends. Because the main carrying beam in the center will shrink and add to the lesser shrinkage at the foundation walls. Check the pitch of the floors in relationship to the direction of the mains under the floor. The old dead guys didn't have the drills we have today and they ran between the joists if possible because running perpendicular to the joist was a lot of work drilling, then cutting and threading pipe.

The place you can see this the worst is where walls intersect gable end walls where there is no bridge blocking from the sill to the first free joist. If a doorway is put against the outside wall, and the hinge side is against the outside wall, the opposite end will start hitting on the top and sticking. If the hinge is on the inside, it will be open on the top/wall side. Some think it is settling. When it is wood shrinkage. Put a 4' level on the floor from the outside wall to the middle. If the floor pitches to the middle, it is usually shrinkage.

Just a point to ponder.

Mark_134

didn't seem to be a problem a month ago, so...

I'll level-it tonight. If this intense, brief banging just started recently- and was not a factor prior to the new gas system as I can recall it, could it be my over-pitch, elevation of the two or three radiatos on the 2nd floor?

BobC

just a thought

Does this occur when the system is recovering from a deep setback?If so you might decrease the depth of the setback or stage it so you end up with two shallow setbacks.



That boiler is probably making steam faster than the old one did so things might be seeing faster temperature swings.



Bob

nicholas bonham-carter

Underfloor water hammer

There could be a horizontal part of the riser which has become waterlogged due to settling, or shrinkage. Jacking up both ends of the radiator can re-level the horizontal.

Are your main vents able to let all the air out with only a couple of ounces of back-pressure, or do you have too much venting on the radiators

Instead?

The old oils and dope may have all come down into the boiler, and perhaps some more skimming will clean it up, and make the steam drier.--nbc

Dave in QCA

another thing to check

Water hammer can always sound like it is very close, even when it is somewhere else.   So, since this problem has arrived with the new boiler, is the water line on the boiler lower than the old one.  Do you have any wet returns in the basement that are now near the water line, or perhaps slightly above it?

EBEBRATT-Ed

pitch

If you pitch one end up the other end must go down. You could be making a low spot in the supply under the floor. If you bring the entire rad up slightly and then pitch the far end up it is possible it might help.

Mark_134

Pictures

I apologize that the pictures aren't. Maybe there is something from these pictures to consider.

Dave in QCA

Picture Help

Mark, in order for the pictures to enlarge properly, when you upload them they must each have a different file name.  If you look, I think you'll find that all of your photos have the same file name.   Also, it helps if you rotate your pictures in your photo edit on you computer and then save the edited image prior to uploading.  That way we will be able to see them.

Rod

Irregular Piping

Hi-  In looking over your pictures I was puzzled by the picture of your riser connections to the steam main(s). What was the reason for piping it like this rather than straight from the header to the main(s)? Could this be the source of the collapsing steam / noise?

- Rod

fixitguy

hmmmm

Is that a bullheaded tee that I see over the riser? Just asking.

fixitguy

hmmmm

Is that a bullheaded tee that I see over the riser? Just asking.

fixitguy

hmmmm

Is that a bullheaded tee that I see over the riser? Just asking.

Mark_134

Explain

Can you please explain what appears concerning, why it should/shouldn't be, and is it an easy fix? Is it related to my hammering or a potential problem down the road?

JStar

Hammer

Another thought.



The indirect tank does not have a tempering bypass. When he boiler is fully steaming, you may be flashing off inside the tank.

Rod

Irregular Piping

Hi Mark- I really don’t know if your piping configuration between the header pipe and the steam  main is what is causing the problems you are having.  All I’m saying is that when you do have a problem like this, any part of  the piping  installation  that  doesn’t follow standard  practice should be suspect.  

    My concern is that this is a counter flow situation meaning that the steam goes up the pipe to the steam main and any condensate (water) tumbles back down the pipe all the way from the steam main to the header. There are a lot of  90 degree turns, a bullheaded tee plus horizontal lengths of piping along the way.  Bob attached a good link which mentions the need for plenty of pitch in a counterflow  pipe.  

   The normal method of piping steam from the header pipe to the steam main is to go as directly as possible and that each steam main should have its own riser pipe from the header. I’m guessing that on your system, if you trace the piping going to the steam main in the left of the picture, the steam path is close to 3 times farther than the direct route and takes 5 more 90 degree bends than it needs to have.  

    When you say the “banging” occurs near the end of the steam cycle, do you mean after the burner has turned off?

- Rod

Mark_134

Hammer

Starting to see a sense of calm among the radiators. Down to the last two (of 7) troublemaker radiators. Too loud, so repitched from a ? too high to 1/2 high, and now a gurgling sound, almost like water sloshing around inside. Is this a pitch, vent or ? situation?  

Rod

Radiator Slope

Hi Mark- You only need enough pitch to "encourage" the condensate (water) to leave the radiator. If you put too much pitch on the radiator, the water pools at the inlet and the steam has to force its way into the radiator.  It's also important that you use a bubble level rather than just raise one end of the radiator. One of my radiators, which I thought had plenty of slope, I found had a slight negative slope when I put a bubble level on it due to sagging of that corner of the house. which I later found out was quite common in older houses.

    If adjusting the slope doesn't fix the problem you might want to consider whether the inlet valve is fully opening.

- Rod

- Rod

SWEI

explained

Nicely here http://www.comfort-calc.net/Steam_Piping_Donts.html

Mark_134

Pictures

This should appear correctly.

Mark_134

Piping

Rod, based upon comments about piping, counter flow, bullhead tee, should i have this corrected? Now it seems the steam has got quite challenge to make it through to the mains. Will they fix this or suggest this is the 'way we do it' mentality. I appreciate your feedback and your time.

Rod

Banging Problems.

Hi Mark-

   I don't know what to tell you on this. This piping is "Mickey Mouse" but whether it is actually causing your problem I didn't know. It looks like the original piping went straight from the boiler to the bull headed tee and all the new guys did was hook up to the tee. Unfortunately this sort of thing is rather typical. Rather than pipe it properly they look for the easiest way to connect up the piping.  Their argument is going to be "well, that was how it was piped originally!"  The counter to that is "if it was piped wrong originally, does it make any sense to repeat the mistake?" 

Have you been able to locate the source of the "banging" yet? If it is in these pipes, you might be able to feel it. Use an oven glove and hold you hand on the pipe. Be careful as these pipes are very hot!  It might help if you could post a few pictures of this piping taken from different angles around the boiler. How is the boiler water? Has it been skimmed?

- Rod