Is it normal for water to pool up in the bottom of my portable dishwasher?

There is a check valve in the hosethat only lets water out of the machine. if it gets hung up it will allow the water that is trapped in the hose after the pump has finished to flow back into the machine.If you pull the hose off where it attaches to the machine you will see it.. Check it out...

On your sink you likely have an air trap that you will hear gurgling when the dishwasher is draining, several times in its cleaning cycle.

It looks like a 2.5" tall by 1" diameter cylinder with a vertical slot in it.

My bet is the air trap has stuff in it that needs to be removed and the rest of the circuit drains into the garbage disposal if you have one.

Remove the cylinder and you will see the sub structure that has a cap that can be removed using two hands to release the grabbers on the side. Once this is done you can see down into the fitting, here is where you will find the obstruction. Fish bones are good obstructions. Clean this out and then take a jug of warm water and pore it into the hole. You may hear or see water running in the bottom of the disposal. This is a good sign! It means the second line from the Air gap to the disposal is clear.

Do this several times a week until the drainage improves then monthly from then on and you should be good to go.

You're welcome!!

If it's not the drain maybe you need to tilt it a little (use a shim) so the water will drain out completely. You know like a window A/C is supposed to tilt up a little so the water will drain out.

the drain is likely plugged up. have an appliance guy come out and fix it (yellow pages for appliance repair) they'll need the brand name. cost? about $35-$50.