Having a problem with a washing machine inlet valve cycling rapidly, causing water hammer.

We recently bought a house with a fairly recent Maytag Centennial top-load washer. In our previous house, we had a pretty old washer.

While the washer is filling on settings other than "cold", the hot water inlet valve will pulse on and off, usually over several seconds. When it shuts off, it does so *hard*. The hot supply line takes a big jump, and the old brass pipes overhead will bang and visibly vibrate. I hear a solenoid-like noise in the washer so I do think it's the valve vs something else obstructing supply.

My first thought was that the washer is designed to do this. I.e., that it has a thermostat and is pulsing the hot on/off to regulate the temperature as it fills. It does pulse more on 'cool' than 'warm', and least on 'hot'.

If so, then we need to do something about the hammer. I do see from other threads that there are some simple arrestors we could try. Any specific suggestions?

However, I'm wondering, is the washer really supposed to pulse the inlet open/shut like that? I am now somewhat skeptical, as just now the pulse rate changed, it was almost chattering with an open-shut maybe once or twice per second, which _really_ had the overhead pipes banging and swaying.

Do modern washers really cycle the inlet on/off? If it's not supposed to, or not with such a high frequency, then instead of a hammer arrestor I guess I need a repair guy out for the machine.

Thanks for any advice!

1 - call Maytag with your operational question

2 - install:



Q. "At what angle can these water hammer arrestors be installed?"
A. Because of their secure water chambers, all Hydra-Restors and Mini-Restors can be installed at any angle.

Q. "We have a high efficiency front loading washing machine. We installed a 660-H on the hot and cold supply lines yet we still have some water hammer noise. How come?"
A. According to the manufacturer one pair of water hammer arresters (Mini-Resters) placed within six feet of the valve should be sufficient to control a pressure rise up to 150 psig maximum and reduce noise caused by uncontrolled water hammer. This should be no different for high effeciency front loading washing machines or common residential washing machines. Most high efficiency front loading washing machines use less water per wash cycle than conventional washing machines. However, their water supply valves turn on and off as many as 16 times per cycle as compared to 3 or 4 times a cycle for conventional machines. This higher supply valve usage may cause a low level, repetitive noise annoying enough to cause the homeowner to assume the Mini-Resters are not working. The pressure surge may be sufficiently controlled by the Mini-Resters and be working as designed yet not eliminate the noise completely. In an effort to further reduce or eliminate this noise, the manufacuter suggests an additional set of Mini-Resters be installed on the supply lines. This means two Mini-Resters installed on each supply hose. With 2 arresters on the cold line and 2 on the hot line, the pressure surge can be further reduced.


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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Never heard of any doing that. The valves are controlled by a water level device, (not a thermostat), and that may be malfunctioning as the water is flowing in to the machine.

hj,

the new high efficiency machines mix the incoming water using an THERMOSTAT wired to an ECM to control incoming water temperature (the cheaper models by modulating an 'old fashioned' dual solenoid valve not really designed for said operation)

the OP needs to call Maytag with his model and serial # to ascertain whether it is or is not operating properly

very sophisticated AND problematic at best

ps.. This is why I decided to preemptively purchase a 2014 SPEED QUEEN washer and dryer before the 2015 models with electronic controls were introduced as mandated by the Feds.

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Thanks to both.

It does sound like something is probably up with the washer. If HE front-loaders are notable for cycling the valves 15 times, heck, mine is probably cycling the hot valve a few dozen times on a full fill. The pulsing starts right away, btw, when the water in the tub isn't anywhere near up to the desired level.

bernebeau:

Oops, you posted while I was writing that.

I'll definitely follow up with Maytag to figure out if mine should be pulsing, and if so if it's doing it properly. If it's _supposed_ to be like this, I'm definitely going to need those arrestors!

I'm not a plumber, but modulating flow with frequent cycling of high-speed, on/off solenoid valves does not sound like a good thing at all for residential pipes. Let alone the cheap rubber supply lines most people use (I replaced with braided s/s when I moved in).

What's the model number?

the braided stainless steel is merely a mesh covering the same 'ole cheap rubber

the PLAIN rubber type would act SOMEWHAT as hammer arrestors

ALL washing machine hoses are recommended for change every 5 years

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638