I have a basement laundry room with washer/dryer and utility sink.

I am receiving no hot water flow out of the valve for the washing machine. I have checked the hose from the wall to washer and it is clear, the screen inlet on the washing machine is clean. The wall valve appears to be opening and closing properly, no water flow, hot or not at all.

The machine has separate hot/cold water hookups and the cold water is flowing normally.

The utility sink next to the washer and dryer is operating normally both cold and hot water.

From what I can tell there is a PEX feed in the ceiling to that room which T's off behind the wall to feed the sink and washing machine. I only assume this because when running cold water into the washing machine and then turning on the utility sink, I see a slight fluctuation in pressure.

I attempted to run a hot water wash yesterday and received an error code of 4C, which is inadequate water feed. I reset the machine and tried again, I received a small amount of hot water that fell to a trickle and then stopped and halted the machine cycle. Cold water continued running normally to the machine.

I live in Maine, we had a colder night the previous evening but have had colder and never had any issues with no hot water to the washing machine. We have piping hot water to every other bathroom and faucet in the house....on demand propane hot water heater. Just nothing to the washing machine. I run a pellet stove in the basement at night and ran a space heater in the laundry room for good measure in case something was frozen but that did not help. Still no hot water or water flow at that valve.

It is an exterior wall, half underground. So behind the laundry room wall is foundation and then insulated and framed exterior wall on top.

Could it possibly be an air lock? Should I connect the cold feed to the hot feed and run cold water back into the hot line?

  • 1
    Sounds like a blockage. Have something in the pipe that is a bit loose, so when you turn on the hot water it moves a bit and blocks where the pipe narrows, maybe at a valve.
    – crip659
    Feb 2, 2023 at 12:13
  • Is the washer supplied with Flood Proof type of supply hoses that have a check valve that shut off flow if it suspects a leak? Perhaps that has malfunctioned?
    – RMDman
    Feb 2, 2023 at 12:23
  • 1
    If there was air in the line, the water would just sputter & spurt as it came out, but it would flow. Have you felt the wall in the areas where you believe the plumbing to run, looking for wetness? There may be a leak.
    – FreeMan
    Feb 2, 2023 at 12:30
  • If the PEX line to the washer is frozen, you might be able to thaw it by running the hot line to the sink. Run it at high flow to establish hot water then fairly low for 30 min, testing the hot valve to the washer every so often. You think the hot water line probably tees inside the wall so maybe you could get enough heat at the Tee to thaw a bockage. Feb 2, 2023 at 12:38
  • 2
    Most likely frozen, in the universe of things that cause blocakges to pipes, even if you didn't have that trouble before. Outside walls are a dubious place to run plumbing in cold areas. Perhaps the mice stole some insulation for their nest...At least with PEX the odds of it bursting are lower than with copper.
    – Ecnerwal
    Feb 2, 2023 at 13:22

1 Answer 1


Here is a quick update.

It was indeed frozen and as suspected comes in from overhead. There is a T fitting where the supply heads to the sink, the lines continues down and at an elbow makes a turn to run about 2 feet to another elbow and then runs vertically to the valves in the wall recess. I unscrewed the recess from the stud and simply pushed it back into the wall, I added some hot air from a hair dryer and had both hot and cold water again. Took about two minutes.

The sink never had a problem with hot/cold supply through all of this...temp last night here was -20F.

So with that being said how can I insulate that run easily? I was thinking of cutting into the drywall below the recess that holds the hot/cold valves to access that run of PEX. Can you guys suggest an insulation from Lowes/HD that I can add to that run of PEX?

Thank you again for the helpful posts. Much appreciated


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