Still have hammer, out of ideas...

nz

I have two bedrooms over the garage. Both had water hammer. I fixed one of them today by raising the radiator about an inch. It's perfect now (other than the vent is a little noisy).



The second bedroom has an attached bathroom, both of which have radiators. This bedroom & bathroom is serviced by the same vertical riser (but a different one than the bedroom mentioned above). The water hammer remains, and it is at the start of the cycle. The hammer seems to occur in the supply line between the two radiators, however I'm not 100% positive.



I have raised both radiators as much as possible. I replaced a trap on one of them (the one in the bathroom - green walls in the picture below). The trap in the yellow bedroom appears to be functional based on the temperature measured by my infrared thermometer.



After about 20 hammers, the system is quiet and runs fine the rest of the cycle.



The vertical riser servicing both radiators is closer to the bathroom (green walls).



I know water hammer usually happens at the beginning of the cycle due to improper pitch, however since I raised the radiators as much as possible - this theoretically should have fixed it - no?



Any ideas would be greatly appreciated.

MotownSteamer

Vents on two-pipe?

Didn't catch that in your other posts. You should not need (or have) air vents on the radiators. They were likely installed in a previous effort to correct problems. Pitch should not matter on two-pipe either. The advancing steam should push the air AND water ahead of it through the trap and down the return. If the air is getting purged out the vent, only the steam is left to hit the water which is causing the violence. I think.



Scott

Jamie Hall

Sometimes...

This sort of problem can be caused by a combination of not enough pitch and too small a runout.  In fact, even with enough pitch if the runout is too small you can get this sort of hammer.  The telltale is takes a little patience -- but only a little: when steam starts to rise, stay at the 90 between the runout and the vertical to the valve.  If it is this, you will get hammer, but only until steam gets to that elbow.  Then it will stop; you may hear some enthusiastic gurgling as the condensate (which forms in the pipe) makes its way back to where it belongs.



In fact, I have exactly this problem in a long, too small, runout to a very big radiator in one of the great rooms  in this ark I super.



The only solution I can think of is a much bigger -- up two sizes -- horizontal run.  Maybe you can do that in your situation.  I can't -- so I live with it.

nz

Supply/Return Lines

Shortly after I posted this, I thought it might be helpful to show the garage below.



This is the back wall of the garage. The supply line riser (yes about 3 feet of it is uninsulated, I plan to fix this soon - the hammer is NOT here) is on the left, the return line is on the right. There is a drip line from a horizontal supply to the right of the return. (The large center pipe is a bathroom drain.)



The bathroom radiator is roughly where the drip line/return line is. The bedroom radiator is at the other end of the garage, close to the right wall (see diagram). While I'm lacking X-Ray vision, I can only presume these two radiators are sharing the same supply and return lines, and the water hammer happens between those two radiators (I can hear it clanging in each of their supply pipes).

nz

Air Vents

I don't have any air vents on the radiators, unless somehow I missed something...just the original dunham packless supply valves and 1E traps. The handle on the valve might be throwing you off?

Jamie Hall

more and more

I'll bet a cup of coffee that it's water in that long line to the bedroom radiator.  Now... that line is long enough so that it is possible that there is a sag in it, in which case -- voila!  Assuming you can get at it...

nz

Garage Ceiling

Sounds like I get to tear the ceiling apart in the garage....at least I don't park on that side of it. The girlfriend won't be so happy lol.

nz

Patience

I patiently waited.



Steam seems to get to the radiators about the same time. Maybe the bathroom a couple seconds earlier. However - the hammer started just before the steam got to the vertical run to the bathroom radiator, and continued for 5 minutes.



I could hear sloshing near the vertical run to the bedroom radiator.



I tried lowering the bathroom radiator to its original level (on the tile floor) prior to the steam's arrival, and that didn't seem to have an effect on anything.

Dave in QCA

drip trap

I am assuming that you have already rebuilt the drip leg trap, that I would presume is at the end of the supply main.  The trap I am referring to is located between the sewer stack and the lavatory in the corner of the garage.

If not, and if this trap has failed closed, the steam main will fill with water and it has no place to go but up through  the supply to the radiators.   That would certainly sound the same as your description.

nz

Drip Trap

Dave - Thanks...you are correct, I already did replace the cap & disc in that trap - I replaced it the other day. It was previously stuck open (return line was 212 degrees) - and I had same the hammer before replacing it as I do now. Now the return is a modest temperature (warm to the touch but not hot.)



I should have mentioned it in this post (I did mention it in another post)

Dave in QCA

whooshing and hammer

Well, it sounds like the main, as it travels above your garage ceiling should be draining to that drip leg trap, and so it should be free of water.  However, the runouts to the 2 individual radiators may be another thing.  I have seen settling, or perhaps marginal installation create improper pitch in the runouts, and when they don't drain back toward the main they will accumulate a puddle of water, which as the steam attempts to come through will hammer and whoosh, sometimes sounds like a miniature water fall inside the pipe.  If this is the cause of your problem, attempting to raise the supply end of the radiator could potentially correct a pitch problem.  It might be a good idea to open up the ceiling and get a good look at exactly what is going on.



How are the rest of the rads in the doing?  Have you got the rest of the traps taken care of?

nz

Hammer Time

Sounds like it will be "hammer" time - putting one to the ceiling that is!



Based on everyone's feedback - it sounds like either a sagging main between the rads, or as you suggested...runouts improperly pitched. I thought raising the rads would have fixed the runouts, but the house could have settled more than I can raise them too. It's a bummer too, because it worked in the other bedroom above the garage.



I've replaced four trap discs and caps so far, out of 29. 1x Dunham 2E, and 3x Dunham 1Es. Since I don't have a replacement cap and disc for every rad yet, I've been strategically replacing them. So far, the replacements on 2 of the 3 1Es seem to have helped.



The third 1E I replaced (on the garage radiator pictured above) - I'm not sure if it was bad before now, or the replacement cap/disc didn't fix it. The return line never gets above 60 degrees F, so I thought it was stuck closed....but the return line is still the same temperature even after replacing the cap & disc and wiping the seat clean. Maybe I should try the MEPCO insert...?

Dave in QCA

orifice

It is possible that there is an orifice or an orifice type valve on that radiator in the garage.

nz

Orifice

Good point - hadn't thought of that. It's an original Dunham valve, but it leaks. I'll make sure to check if it has an orifice when it is replaced.



I'm okay with popping trap caps in the winter, but I don't have the canjones to try to replace a valve myself this time of year. I have at least 9 valves that need to be replaced (they leak air/steam), and 6 have been replaced so far in recent years (likely without orifices).

MotownSteamer

Venturi effect?

Ok, I'm out on a limb here I'm sure but......



See Nick's picture of the drip? It's looped into a trap but water would always be in that 8" bottom leg, right? The part that's below the trap would never be void of water.



So, when the system cycles, maybe the water is getting launched up the main by the movement of the steam? And, the gurgling sound he's hearing could be the turbulence of whatever water droplets are not lofted away?



Which would beg the question....why is that dead-end there? In fact, I wonder why the drip is there at all......

Dave in QCA

Normal piping configuration

I am reposting an image with labels applied.  I'm not sure if we are all understanding what we are looking at. 

The end of main drip leg and crossover trap is pretty much normal piping set up for this type of condition.  The sediment chamber is also normal protection upstream of a trap.  It will not cause any issues and will not cause the condensate in that leg to be thrown against the flow of steam and back up into the piping above the ceiling.

The hammering must be coming from improper pitched piping above that garage ceiling.



Compliments to Motown for going out on that limb.....    always helpful to consider all possibilities.

nz

Thank you

MotownSteamer happens to live about 2 miles away from me, so he came over yesterday and we walked around and looked at the situation.



Dave - Thanks for the image with the labels - that is exactly what everything is



From what I gather, I have two possible reasons for the hammer:



1. Improperly pitched main (and possibly a return) due to the house settling more on that end.

2. Main is sagging between the two radiators.



And I have two options:



1. Cut into the wood floor and subfloor and try to bring the elbow near the radiator up, but this will only work if the pitch is improper.

2. Cut open the plaster ceilings in the garage and fix the sag and/or pitch.



Based on the two options...I think I will probably go with option #2 since I'd rather fix plaster/drywall than a wood floor, and it lets me fix both problems instead of just one. And I don't want to mess up the nice hardwoods below the carpet, in case my sawzall gets a little overzealous



You guys rock, that's all I have to say.

Dave in QCA

Great!

Hey, cool that Motown lives close.  I'd love to have had the grand tour too!  I think that you are totally on the right track and am eagerly waiting to hear how this turns out! 

If you turn off the rads in the rooms above the garage, do you still get hammering?  If so, it is definitely in the main above the garage ceiling.  If it only hammers when the radiators, (not the one that you corrected) are turned on, then the problem is probably in the lateral run-out



It almost certainly is not hammering in the return piping, as there would have to be steam in there for that to occur, and unless you have traps that have failed open, it could not be the cause.   Also, if this were the case, it would only hammer only after the rads were fully heated.



It would be good to inspect the return piping for proper pitch, because a puddle in that line will create problems with getting the radiators vented out and will slow down the arrival of steam to this group of radiators.



Good luck with it!

Dave in QCA

Time for a Progress Report

Nick,  I'm bumping this thread back to the top in hopes that you will give us an update on your progress and what you found above the garage ceiling.

nz

Not Yet...

Dave,



Haven't opened up the ceiling yet - I have had a bunch of family stuff going on this week - so it is on my to-do list for later this week or weekend



I am eager to fix this, as the hammer is worse with the colder temperatures...it "came back" in the other room - I can't jack up the radiator any higher so I'll have to open up the ceiling over there too.

Dave in QCA

thanks

Thanks for the update.  Keep us posted.

nz

Water Hammer Fixed!

Well, I hired a company to raise the garage.



They had to stop before they were able to raise it to completely level (an issue we're still working out) but the water hammer stopped - on all three radiators above the garage.



It's been over a year since the last post - but I wanted to circle back and let Dave in QCA I fixed it

Dave in QCA

Great news!

Nick, Thank you for taking the time to let us know how this turned out. Do I understand the project to mean that you actually had the entire structure lifted up off the foundation and leveled?

nz

Lifting

I actually had helical piers installed under the foundation. They are drilled ~33ft below the 42" foundation, and they are bracketed to the bottom of the foundation.



Then, the entire structure was hydraulically lifted across 10 points along the foundation.



This way, the foundation will stop sinking and the problem should be permanently fixed.

Dave in QCA

Oh Those!

I am familiar with the helical piers. That should be a great thing for your house and should last a very long time! At our Grandview property, we used the same devices, except installed as helical tiebacks, 24 of them! They were used to provide lateral stability to the foundation and an auxiliary support structure adjacent to and tied to the foundation of the garage building. It is at the edge of a 50-60 ft bluff and the wall was beginning to move laterally.