WF218ANB/XAA NF error

[Samsung1980]

My washer gets a NF error several times during a wash cycle - on the cold water fill the water just trickles in.  The hose is good and the water pressure is fine so I figured it was the valve and      replaced it today but still have the same problem.  I'm getting 118 volts to the right side (blue wire) but it acts like the valve just doesn't fully open.  Could it be the main board or did I possibly get a new valve that is defective?  Any help will be appreciated. 

[Hiroshi]

If you detach the cold hose at the valve and hold it over the sink, does the water blast out when you turn it on or just trickle? Are you on city water, or do you have a well and pump? Is there 120V at the cold water solenoid when the valve is energized, or are you checking it at rest? some controls provide a neutral and the 120VAC may drop out under load... if this is the case, replace the main PCB. You can also check the tube from the valve to the fill spigot where water enters the tub, it could be constricted by hard water scale, but that would make the Hot fill trickle also...

[Samsung1980]

With the hose disconnected the water has a strong stream.  I have a well and pump with good pressure throughout the house.  With the cold water valve energized I have between 118 and 119 volts on both solenoids.  I'll run through Quick Test mode later this afternoon and verify the hot water valve is pulling the same voltage.

[sh2sh2]

2 hours ago, Samsung1980 said:

With the hose disconnected the water has a strong stream.  I have a well and pump with good pressure throughout the house. 

So good water running thru hose,?, check the inlet screen of the new valve to make sure there is no sediment in it

[Samsung1980]

Problem solved.  The cold water inlets into the plastic box that funnels the water into the washer were clogged with calcium.  Opened them up with a small piece of wire and all is well.  Thanks for your time.

[Hiroshi]

Be sure to note when you get weak flow, I have seen homes with a good well and pump get periods of decreased pressure when other water-using fixtures are on when you are trying to wash... dishwasher, washing machine on, while someone is in the shower? If the low pressure is not house dependent, try swapping the hoses and see if it affects flow. You can also try to backflush the valve by disconnecting the cold supply, then choosing "Warm" fill option, this will open both solenoids and let warm water push through the cold side of the valve body backwards... if there is any sediment in there, this should dislodge it. Keep in mind to have a towel and bucket handy, as water will pour out of the valve.

In a case like this, variables begin to stack-up, so be extra deliberate and close  all the blind alleys you can to slowly rule-out each possibility!