Sharkbite water hammer arrestor on hydronic heating zone?

ericstralow

Hi all.

I have a 2 story home, one heating zone per story. When the second/upstairs zone valve closes, I get something that sounds like pretty severe water hammer. That led me to the following thread: https://forum.heatinghelp.com/discussion/74423/zone-valve-slamming

I can probably do more to secure pipes, but I fear it may cause more harm than good if I don't fix the root problem. I'll consider changing/modifying zone valves, but I've never done it... worth noting that they seem to be piped in the correct direction.




Which leads me to my question: is it unwise to install a water hammer arrestor above this zone valve? Specifically this one: https://www.homedepot.com/p/SharkBite-3-4-in-Push-to-Connect-Brass-Residential-Water-Hammer-Arrestor-Tee-22632LF/204417399?source=shoppingads&locale=en-US&mtc=Shopping-VF-F_D26P-G-D26P-26_1_PIPE_AND_FITTINGS-MULTI-NA-Feed-LIA-NA-NA-PIPE_AND_FITTINGS_General&cm_mmc=Shopping-VF-F_D26P-G-D26P-26_1_PIPE_AND_FITTINGS-MULTI-NA-Feed-LIA-NA-NA-PIPE_AND_FITTINGS_General-71700000055362044-58700005218218026-92700046076001587&gclid=EAIaIQobChMIsMix3LSA7gIVxZ2GCh172gylEAQYAiABEgIVVPD_BwE&gclsrc=aw.ds



Like so:


The PSI + boiler output temps seems within range of the sharkbite specs.

Any thoughts would be appreciated! Thanks!

EdTheHeaterMan

I think Dan H has a story about this phenomenon. If you ask Honeywell about it, they might say "they have never heard that complaint before"... LOL

Removing one of the return springs on the actuator may resolve the issue. Try that first. It doesn't cost anything.

pecmsg

Can we get a picture of the supply and return piping along with the pump?

those are slow closing, doubtful its in the valve.

What size circulator?

EdTheHeaterMan

pecmsg said:

Can we get a picture of the supply and return piping along with the pump?

those are slow closing, doubtful its in the valve.

What size circulator?

The springs on these valve actuators are pretty strong. and there are two of them. The closing starts off fairly slow but by the end of the "Throw" of the actual valve the little ball inside the valve body can slam pretty good. I don't dought it is the valve.

If the other zone is also calling at the time, and the problem zone is satisfied, the circ pump is still moving water at the 4 GPM rate thru the 3/4" valve and that will cause some pipe movement. I'm not sure the hammer arrestor will solve the problem. If you already purchased it and you want to give it a try, it won't hurt. I just think the free fix is the first step.

Mr. Ed

P.S. If you do that repair and it does the same thing... What will you check next?

Big Ed_4

The zone valves should be on the return if the circulator is the supply , or visa versa ... If they are close together with that make zone valve you may get a hammer if one of the other zones are still calling . Removing one of the springs will allow it to close slower . 'It's a late night fix ... And yes they hammer if the arrow is against the flow ....

EdTheHeaterMan

Youngplumber said:

Am I wrong that he needs a differential pressure loop and valve? Maybe I'm not clear on what's exactly happening. 

No Diff press bypass needed here. If the circulator is something like a B&G 100 or a Taco 007, the pump curve is relatively flat. so the pressure difference (pump head) between say 20 GPM and 4 GPM is less than 1 PSI difference. That is why those circulators are so good on zone valve systems. Here is an excerpt from my GoTo book on the subject.

The TACO 007 is like the B&G100 little brother... same curve just a little lower on the graph. I like TACO but there are other companies with similar pumps.
And nowadays we have more choices with ECM variable speed pumps with all kinds of choices on pressure difference, temperature difference, and flow rate, all able to be programmed to accomplish different needs based on different systems.

Still need to know how to work on the old stuff though.

This info is on page 15 and 16 of this text.
http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf

ericstralow

Thanks for all of the thoughts everyone.

@pecmsg / all: pictures attached. In short, when my upstairs zone turns off, I get a banging in the wall that reverberates through the whole system in that zone. As per the Nest screenshot, it happens like 40 times a day, so I'm about ready to jump out a window.









@EdTheHeaterMan I'll try removing a spring, but I am curious as to your thoughts about the water hammer arrestor. Obviously, I don't want to cut any pipes if I can avoid it, but yeah...

Thanks again!

EdTheHeaterMan

Try spring first. If the water hammer goes away or is lessened to the point where the noise is acceptable, then it's fixed and there's no need to cut any pipes. AND IT IS FREE!

Lookin' after the best interest of the customer. The customer will appreciate that and become a loyal customer. That is how I operated my business, Not going to change now!

Getting lots of calls from my previous customers who are unhappy with the new company. I guess I spoiled them.

Yours Truly,
Mr. Ed

hot_rod

Your expansion tank is already acting as a water hammer arrestor, assuming it is not waterlogged.
With 4 or more zone valves you should have a pressure bypass valve installed, IMO. looks like you have 5 zone valves?

Personally I would use a Delta P ECM circulator that would adjust to the number of zones calling and prevent over-pumping.
While you are at it the circulator to expansion tank relationship is not ideal.

The circ should be downstream of the expansion tank, or an easier fix would be to move the tank near the inlet of the circ in its current position.

Some good reading on circulators
here.https://www.caleffi.com/sites/default/files/coll_attach_file/idronics_16_na_0.pdf

ericstralow

@EdTheHeaterMan I think you may have done it. I've had half a dozen techs look at the problem over the last 5 years. People were talking about ripping up floors and walls, replacing boilers, etc. Not one person thought to pop a spring off... frankly, none of them thought it was water hammer or valve-related, but I digress. Needless to say, I'm grateful and in your debt. Thank you SO MUCH for the help!

pecmsg

Cycling like that sounds more like a controls problem. I’m not a fan of nest. Change the thermostat see if the noise goes away.

EdTheHeaterMan

ericstralow said:

@EdTheHeaterMan I think you may have done it. I've had half a dozen techs look at the problem over the last 5 years. People were talking about ripping up floors and walls, replacing boilers, etc. Not one person thought to pop a spring off... frankly, none of them thought it was water hammer or valve-related, but I digress. Needless to say, I'm grateful and in your debt. Thank you SO MUCH for the help!

Don't thank me alone, I only found out about it by reading stories on HeatingHelp.com. Thank the whole group! Especially @DanHolohan and @Erin Holohan Haskell

ericstralow

Thanks @DanHolohan and @Erin Holohan Haskell!

Erin Holohan Haskell

Thanks to all for being so generous with your knowledge and time, for helping others, and for paying it forward when you've received help.