Washing Machine water hammer

[Rsmith99]

I had to have my house replumbed when my polybutylene pipes failed. I now have PEX everywhere. The water main was not changed. The water pressure has not changed (75psi).
First thing I noticed was my Toto toilets had a hard time stopping. I had to turn down the shutoff valve to reduce the volume of water.
The second thing is changing the plumbing has caused my Speed Queen washer to create a loud water hammer noise when it finishes filling.
Has anyone used the small expansion valves that connect to the washer supply lines?

 

[Terry]

You will need hammer arrestors for the washer. An expansion tank isn't the answer.

Fit's onto your valves and then the washer hose attaches to the threads at the bottom.

Also good to have arrestors for the dishwasher and the icemaker.

 

[Sponsor]

 

[Jadnashua]

As to your toilets, first, you have fairly high water pressure which will shorten the life of the seals in the toilet fill valve (and others, too). So, you may want to pick up some replacement caps. Those are replaceable without tools and the instructions are on the package. Many Toto toilets use a valve made for them by Korky. If yours does, the caps will restore operation to like new most of the time.

Second, while 75-psi is within the code acceptable range (80 or less), it's still pretty high. This makes it harder for any seal to stop the water and makes the water flow faster which makes water hammer more likely and stronger when it occurs. Then, if you have a closed system, that 75psi may get significantly higher after using some hot water, and an expansion tank might be called for. Where I live, an ET is required by code, and may be a good idea many places.

 

[Rsmith99]

You will need hammer arrestors for the washer. An expansion tank isn't the answer.

Fit's onto your valves and then the washer hose attaches to the threads at the bottom.

Also good to have arrestors for the dishwasher and the icemaker.

Thanks Terry! Is that the brand you recommend?

 

[Rsmith99]

As to your toilets, first, you have fairly high water pressure which will shorten the life of the seals in the toilet fill valve (and others, too). So, you may want to pick up some replacement caps. Those are replaceable without tools and the instructions are on the package. Many Toto toilets use a valve made for them by Korky. If yours does, the caps will restore operation to like new most of the time.

Second, while 75-psi is within the code acceptable range (80 or less), it's still pretty high. This makes it harder for any seal to stop the water and makes the water flow faster which makes water hammer more likely and stronger when it occurs. Then, if you have a closed system, that 75psi may get significantly higher after using some hot water, and an expansion tank might be called for. Where I live, an ET is required by code, and may be a good idea many places.

I have an expansion tank on the hot water tank.
Is it worth the expense to have a pressure regulator added out by the city water meter? I think it would be about $350.

 

[Terry]

I don't know which brand of hammer arrestor is best. And at some point they can fail and need replacing.
75 PSI is fine for pressure. You're allowed 80 PSI before it needs a PRV. Most of the PRV's you buy come preset for 60.

 

[Jadnashua]

Higher pressure is a tradeoff...the water flows faster, making a water hammer situation worse, the washing machine, tub, etc., will fill (slightly) faster, and the shower will be a bit more aggressive in the spray, but in a shower, it's more about the head design than pressure. HIgher pressure will also make it harder for any valve to function.

You don't NEED 75psi, and note, the pressure may not be consistent throughout a 24-hour period...IOW, it could be quite a bit higher at night versus during the day, so if you're going to check it, you want a gauge with a peak reading hand to see what it is peaking at after leaving it attached at least for 24-hours.

Where I grew up, before we installed a PRV, turning the kitchen faucet on full could blast a glass out of your hand if you weren't ready for it! That was before they were flow restricted by many decades, though.