Possible causes for HF error. It is in the cold

If you have hot or warm wash selected and you get no hot water, a possible cause is that the solenoid inlet valve on the hot connection has failed. Try connecting the hot tap to the cold inlet on the back of the machine, and selecting cold wash. If you then get hot water coming in you will know it is almost certainly the solenoid inlet valve on the hot connection.
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This error code indicates that the cold and hot water inlet hoses are switched.
This code will appear at the end of the wash cycle to indicate that the cold and hot water inlet hoses are switched. If an error code does not appear, but you are experiencing poor wash performance, check to see if the inlet hoses are reversed.

Chris an F-20 is usually a clogged filter on duet washers. Did you go by the tech sheet in your machine? It gives the codes and remedys and is in a jacket behind the kickplate which you remove to get to the filter. You will need a quarter inch nutdriver to gain access.
SERVICE MANUAL is HERE on my manual page






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Hi from retired Englishman in SW France,
'hf' normally means there is a problem with the water inlet(s).
If you have checked that the hot water tap is turned on fully and the hose is not kinked or squashed at the back, it is worth while checking the hot water inlet filter. Turn the tap off and remove the hot water hose at the washer end. Inside the inlet port there is normally a little filter which should just slide out. Clean if necessary and replace it and the hose. If after turning the tap back on there is no improvement, carry out the same with the cold water system. If there is still no improvement the problem is symptomatic of a malfunctioning water control valve. Sorry but it needs a service call ;-0(

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John C

go to appliancerepairplanet.vstore.ca for a suppot

I believe the code HF is telling you that you are not getting hot water. Check faucet in back and make sure water is turned on at both hot and cold valves. Even if you only use a cold setting, the hot water needs to be turned on. Also check washer fill valve screen. Turn off water and take off hoses at washer. Inside valve are sceens that may be clogged.

This error code indicates a water supply problem.
Are both the hot and cold water faucets turned on?
Turn on the water. Check the household faucets to see if the hot and cold water faucets are turned on. Completely open both faucets for proper fill.
NOTE: Both hot and cold water must be connected to the washer and turned on; the washer will not properly operate with only one incoming source of water.
Are the water inlet hoses kinked?
Straighten the water inlet hoses.
Are the water inlet valve screens on the washer clogged?

This error code indicates a water supply problem.
Are both the hot and cold water faucets turned on?
Turn on the water. Check the household faucets to see if the hot and cold water faucets are turned on. Completely open both faucets for proper fill.
NOTE: Both hot and cold water must be connected to the washer and turned on; the washer will not properly operate with only one incoming source of water.

Are the water inlet hoses kinked?
Straighten the water inlet hoses.
Are the water inlet valve screens on the washer clogged?


Turn off the water and remove inlet hoses from the inlet valves in the back of the washer. Inside the inlet valves are screens. Remove any accumulated film or particles from the screens. Reinstall hoses, turn on water, and check for leaks. See the Installation Instructions for details; find them by entering your model number in the search tool below.
Is the water pressure less than 10 psi?
If the water pressure is too low, the washer may not properly operate. To find out your exact pounds-per-square-inch (psi) value, contact your local water utility company.
Are you using HE High Efficiency detergent?
Use only HE High Efficiency detergent. Using non-HE detergent, or more than the manufacturer's recommended amount of detergent, can cause excessive suds. The excess suds can prevent the washer from detecting the incoming water.
Concentrated detergents labeled 2x and higher will require a small amount of detergent based on load size. Always follow the manufacturer's recommendations.

See also: Why HE High Efficiency detergent is required.
Are you using flood-preventing inlet hoses that can shut off the water to the washer?

These hoses have a valve inside that will close if the water pressure is higher than two gallons per minute; this will shut off the water to the washer. If one of these hoses becomes loose, the water flow through the hose will increase and close the valve inside the hose, which will shut off water to the washer to prevent a possible leak or flood. If the hose is not loose, try taking the hoses back to the store for a replacement set.

To remove the error display, press Pause/Cancel twice.


If Pause/Cancel does not work:

1. Unplug the washer or disconnect the power for one minute.
2. Plug in the washer or reconnect the power.
3. Re-select the cycle and press Start.

NOTES:

• On some washers, when the washer is started for the first time after this error code, it will begin to drain. You will not be able to pause or cancel the cycle for about 8 minutes while it drains. This is normal.
• If the error remains on the display, and all of the other conditions above have been checked, call for service.

F/H No water detected entering machine or Pressure switch trip not detected.
If after 30 seconds the control does not detect water entering machine and then valves will be turned off and the error code will be displayed.

Or

If the control has turned the water valves on and after 8 minutes the flow meter has detected 10.5 gallons of water passing through it, but has not detected the pressure switch trip, the valves will be turned off and the error code will flash.


Press PAUSE/CANCEL twice to clear the display. 
If there is no water in the unit:
1. Make sure that both valves at the water source(s) are turned on all the way.
2. Check for plugged or kinked inlet hoses or plugged screens in the inlet valves 
3. Verify inlet valve operation 
If there is water in the unit:
1. Verify Drain pump operation
2. Pressure Switch Hose is in good condition and properly connected to Tub and Pressure switch 
Verify there is not a siphon problem 
Verify wire harness connections to:Inlet Valves, Pressure Switch, Drain Pump, Flow Meter, and Central Control Unit (CCU) 
Check all hoses for possible leaks 
Verify pressure switch operation

Verify flow meter operation 
Verify CCU operation.

no way to unclog other than removing sedimet from screen assy. internally nothing need to replace.inlet watervalve 1 piece for both hot and cold water.