U3 error Water not draining

There are a few reasons for U3 to appear.

One that is most common is due to water not filling in time before the wash cycle commences. This can be due to water pressure setting not being consistent with the mains water pressure. Check this by confirming if you are in low water pressure or normal pressure area. The dishwasher should be set at LP or HP accordingly. Refer to the manual for the procedure.

The U3 error code could mean a few things. Not sure if you get it in both or just one drawer.

It could mean there is something blocking the drain pump. Lift the filter plate and drain filter. Then remove the rotor by disengaging the collar holding the impeller and rotor assembly. clean the area including the channel between the rotor cavity and the drain sump. Put everything back and test.

If this does not get rid of the U3 then it is possible there is a kink in the drain hose. Pull the drawers out and check behind. If nothing visible then other possibility is the inlet water pressure setting is not correct. If you know how to read the water pressure setting from the display then compare the setting on the two drawers.

Please post a comment to let me know what you find.

I believe U3 error on your model of dishwasher could also mean a couple of other things like either the drain hose has an obstruction (kink) or the inlet water pressure is not correct.

Hope this helps in finding out what could be the actual reason. T

o find the kink if any, pull the drawer out as much as possible and feel the hose. Might be better if you took the bottom drawer out from the casing and inspect the hose completely. As the problem is limited to upper drawer you do not have to worry about what is under the bottom drawer. Check the water pressure setting is same for both drawers. If so then that is not an issue as bottom drawer is working ok according to your description. See your manual for instruction on how to check the water supply pressure setting on your dishwasher.

This applies to all DD601 and DD603 dishdrawers.
U3 is either one of the following:
- Drain pump is blocked.
- Drain hose is blocked.
- Sprayarm or rotor not turning freely.
- Motor electronics have failed.
- Machine set to 'LP' on a high pressure water supply.

Often it's just the last one, "Machine set to 'LP' on a high pressure water supply.", as this can be unintentionally changed by a user from an uncommon course of events. Sometimes, due to the technical design of the way the buttons work, if water bridges the 2 "Programme" and "Eco" buttons (inside on the top right of the tub), pressing either one, or both, (or just having your finger in the water) for longer than 5 seconds brings up a special mode that a user, in their ignorant attempts to get out of it, can erroneously change the pressure setting, subsequently causing a U3 error. It happened to me once when I was cleaning the machine, wiping around the Programme buttons.

To change to the proper High or Low Pressure settings:
1) LCD Display on. Hold the Programme and Eco touch switches simultaneously for 5 seconds.
2) Machine beeps and "HP" or "LP" is displayed in the LCD.
3) Push the Start/Pause button to toggle between them.
4) Push the Power button when correct selection complete.

Error code U3 could mean the drain pump could be blocked.

Remove the trays and the impeller arm. Empty the water with small container or towel. Open the filter plate and drain filter. Get the motor out and check the cavity for any rubbish. Also use a stiff thin wire to clean the passage between drain filter and motor cavity. The instructions for removing the filter plate and motor assembly are in the user guide.
Good luck

Error code U3 could mean the drain pump is blocked.

Remove the trays and the impeller arm. Empty the water with small container or towel. Open the filter plate and drain filter. Get the motor out and check the cavity for any rubbish. Also use a stiff thin wire to clean the passage between drain filter and motor cavity. The instructions for removing the filter plate and motor assembly are in the user guide.
Good luck

U3 means the tub filled to quickly or the water failed to drain. Do you have very high water pressure? are you using the wrong detergent? eg you can't use tablets (powerballs) etc in the unit. Try putting half a cup of white vinegar in the tub to kill any foam. Check there isn't anything stuck under the motor rotor inside the tub and the there's no signs of damage. Put the drain hose in a bucket and see if the water drains ok when the unit starts? If everything seems ok I'd suspect the main motor controller module but it may be worth getting an appliance tech to inspect unit first as it's hard without seeing this unit. feel free to ask any questions. Cheers

That's a "Low Pressure" fault and it's possible you may only need to reset the mode. This question is posted under DD603 but a U3 code is usually associated with the 602 models. I am including an instruction for you on how to check the setting. Start with that first, it is easy to do.
Let me know if you are not able to read the text.

I have had my Fisher Paykel dishdrawer for 8 years and it has never completely worked. I would get a U3 code on the top drawer intermittently. I have had my drains rerouted twice, LP - HP reset, service men replace the back flow flap and mother boards without luck... until I was able to get my hands on the service manual. Turns out the solution is quite easy. If you have a problem with the U3 code it means the drawer is not draining appropriately, The washer only gives a preprogrammed 60 sec to drain the drawer. So if your drawer is overfilled, it will think it has a drain problem. The following is taken from the service manual...

"U3 - Time to fill was too short, indicating water was still in the tub.
Possible Causes:
· Drain pump is blocked.
· Drain hose is blocked.
· Sprayarm or rotor not turning
freely.
· Motor electronics have failed.
· Machine set to 'LP' on a high
pressure water supply.

The tub fills with approximately 2.2 litres of water, level with the base of the spray arm attachment. Once this level is reached, the wash pump (which has sensed the fill at 30 second intervals during the fill), becomes primed and pumps the water through the spray arm which will then rotate.
The water level is monitored by sensing the motor load through the electronics."


The solution is to turn your water supply valve part of the way on to limit the gpm flow to the drawer. This way, the drawer will not have over-filled in the 30 sec it took to sense the motor load. I have tried it and wow no more U3. Hope it makes sense and hope it works for you.
jim

I have had this problem and went straight to one of the F&P engineers... U3 will display because the water did not drain from the previous stage in the cycle... Check the HP/LP settings first as this will give the impression the water did not drain if incorrectly set. Otherwise the pump may be damaged, blocked or the waste hose blocked. Check these next. I found a little sticker in the waste pipe.
Happy fixing.
Rich