Water Hammer Arrestor for FL washer?

The sound of the banging pipes does indicate that perhaps things aren't secured well. This is a common issue with PEX also when loops in the walls will move around a "slap" against the drywall (PEX has less hammer issues overall though). Properly restraining the plumbing is advisable but remember to allow the ability for the pipes to slip axially in the clamps otherwise thermal expansion will cause noise from the pipe creeping in overly tight clamps...

Even with properly restrained plumbing, adding a little cushion into the system helps absorb the shocks that rapidly closing valves create. Having higher then average water pressure can make this worse too.

The cushion is easily provided by trapping some air in the system to act as a spring to absorb the shocks from the non-compressible water. This can be as simple as designing in some vertical sections of pipe that go above horizontal runs therefor trapping a bit of air. The problem with a simple air trap is that eventually the air will disolve into the water and the trap will fill with water.

Most all the commercial products have either a piston or a diaphragm inside to prevent the water from contacting the air and eventually waterlogging the device.

The simplest use of an arrestor is to buy the ones that install at the shut off valve or on the rear of the washer using garden hose thread connectors. Alternately they could be permanently into your plumbing if you are handy and don't want them in the way.

For the permanent installation style I really like the blue Watt's models that use an internal rubber diaphragm. I used to work for a company that built water cooled soldering machines, they would pulse the hot/cold input valves for temperature control. We shipped a couple of these with every machine sold to prevent problems.

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Post# 838813 8/31/2015 at 09:38 (3,153 days old) by tvq1 ()
Checkrate/Likes We are going to be installing a new washer and dryer soon. We are leaning towards the front load LG4270. I've read about issues with banging pipes on front load washers. We'd like to avoid this issue, and have looked at some water hammer arrestors. There seems to be conflicting opinions on where an arrestor should be installed to be most effective. Opinions? Advice? Recommendations for a specific brand? Thanks!

Post# 838820 , Reply# 1 8/31/2015 at 10:34 (3,153 days old) by ea56 (Cotati, Calif.)
Checkrate/Likes I have an LG WM3170CW and I first installed the arrestors on the outlets and it did help some, but I switched them to the inlet valves at the back of the washer, water hammer completely gone. So my recommendation is to install them on the inlet valves. I bought Sioux Mini Arrestors at Home Depot for $9.99 each. This post was last edited 08/31/2015 at 11:48

Post# 838958 , Reply# 2 9/1/2015 at 06:23 (3,153 days old) by arbilab (Ft Worth TX (Ridglea))
Checkrate/Likes A properly-designed washer valve does not 'slam' shut. At least they didn't from the 60s to the 00s. Rather they 'ramp' closed over roughly 2 seconds. You could see and hear it happen. THESE (rolleyes) days, no telling what passes for design. So better spend $20 more to accomplish what the machine itself SHOULD have. It doesn't cost anywhere near $20 to design and build the machine's valves properly. Obviously, since the solution only costs that much INCLUDING mfg/wholesale/retail markup. But that's just how niggling* manufacturers have gotten. *niggling: "Annoying, troubling, or irritating in a petty way".

Post# 839163 , Reply# 3 9/2/2015 at 05:43 (3,152 days old) by retro-man (- boston,ma)
Checkrate/Likes 1 My 2 cents on this. Water hammer arrestors are just covering up a problem with your pipes. The reason you hear pipes slamming is because somewhere along the line something is loose. I had this problem in another house and followed the pipes which were exposed. I tightened and added additional clamps . This removed all slamming noises. My feeling if they are loose and moving you may have additional problems in the future from leaks at joints. Again just my take on this. Jon

Post# 839172 , Reply# 4 9/2/2015 at 07:13 (3,152 days old) by joeypete (Concord, NH)
Checkrate/Likes Now I know why this was happening at my previous residence. My roommate had a set of LG front loaders and the pipes would bang as it filled. I always thought it was weird. I used to put the delay wash on to start in the morning and it made a good alarm clock. haha

Post# 839206 , Reply# 5 9/2/2015 at 10:20 (3,151 days old) by kb0nes (Burnsville, MN)
Checkrate/Likes 1 The sound of the banging pipes does indicate that perhaps things aren't secured well. This is a common issue with PEX also when loops in the walls will move around a "slap" against the drywall (PEX has less hammer issues overall though). Properly restraining the plumbing is advisable but remember to allow the ability for the pipes to slip axially in the clamps otherwise thermal expansion will cause noise from the pipe creeping in overly tight clamps... Even with properly restrained plumbing, adding a little cushion into the system helps absorb the shocks that rapidly closing valves create. Having higher then average water pressure can make this worse too. The cushion is easily provided by trapping some air in the system to act as a spring to absorb the shocks from the non-compressible water. This can be as simple as designing in some vertical sections of pipe that go above horizontal runs therefor trapping a bit of air. The problem with a simple air trap is that eventually the air will disolve into the water and the trap will fill with water. Most all the commercial products have either a piston or a diaphragm inside to prevent the water from contacting the air and eventually waterlogging the device. The simplest use of an arrestor is to buy the ones that install at the shut off valve or on the rear of the washer using garden hose thread connectors. Alternately they could be permanently into your plumbing if you are handy and don't want them in the way. For the permanent installation style I really like the blue Watt's models that use an internal rubber diaphragm. I used to work for a company that built water cooled soldering machines, they would pulse the hot/cold input valves for temperature control. We shipped a couple of these with every machine sold to prevent problems. View Full Size

Post# 839213 , Reply# 6 9/2/2015 at 10:53 (3,151 days old) by tvq1 ()
Checkrate/Likes Thanks for the info! My husband just explained to me that our pipes probably couldn't "hammer" or bang, because they are not copper. Unfortunately, our pipes are the old horrid poly-butelaine (sp??). However--they do have copper fittings which works in our favor. My biggest concern was not with the noise, but protecting our plumbing pipes from excess forces and a possible break/leak situation. I'm thinking there is no reason to NOT install an arrestor. Is there a downside to having a water arrestor? Thanks again!

Post# 839224 , Reply# 7 9/2/2015 at 12:18 (3,151 days old) by nmassman44 (Brooksville Florida)
Checkrate/Likes 3 What some are missing the point of having a water hammer arrestor is the fact that it also protects your faucets and toilet valves, not just the banging issue. Just those two arresters will save you a lot of headache later on down the road.

Post# 839233 , Reply# 8 9/2/2015 at 13:16 (3,151 days old) by ea56 (Cotati, Calif.)
Checkrate/Likes In my opinion there is no down side to installing hammer arrestors, it protects your plumbing from damage as stated in reply #7 by Mike. And while water hammer may be an indication of loose pipes in the wall, who in their right mind is going to start ripping out drywall to look for potentially loose pipes? An ounce of prevention is worth a pound of cure, and at $20.00 it's cheap insurance. BTW, I only had a problem with this one time before, with a Fisher-Paykel Eco Smart that we bought in 2006, but it was much worse! The sound that was made when it filled would have woke the dead! I was very happy to get rid of this FP set. And the top load dryer was slower than the second coming of Christ

Post# 839577 , Reply# 11 9/4/2015 at 16:13 (3,149 days old) by washer111 ()
Checkrate/Likes Before we replaced our 1984-era solar water heater (who was very nearly rusted through, and probably would have sprung a leak, given chance, by 2013), the plumbers seemed to think ripping off the old water hammer arrestor was a good idea. They didn't even consult it. The device looked very much like a steam-whistle, a long, thin object as seen in some examples here. Despite its advanced age, it still work. Nowadays, if you close the kitchen faucet to quickly, you get a dull clunk. The washer ALWAYS causes a "CLUNK" in the wall as it starts to fill, if it hasn't done so for a while... You, I think our house might be possessed, what with all these noises.

Post# 839554 , Reply# 9 9/4/2015 at 12:12 (3,149 days old) by Letsgoblues ()
Checkrate/Likes I have an LG 3050cw and I have arrestors at the machine and at the wall. (When the house was built 10 years ago, it came with them installed at the wall. After about a month using the the lg washer, pipes began banging so we then added them to the rear of the washer also.) Didn't help me at all. Hope it works better for you. 👍

Post# 839568 , Reply# 10 9/4/2015 at 14:16 (3,149 days old) by ea56 (Cotati, Calif.)
Checkrate/Likes I just have my hammer arrestors installed on the inlet valves at the rear of the washer and I have no water hammer at all. I first installed them to the fill valves at the wall, and while they helped some intalled the way, switching them to the present set up works perfectly.