Can't program my machine....its a model no.sup02148dr

Shut of valve may not be set properly or you selected a cup size too large for the vessel you are using. Call 1-866-901-2739 for help with this issue.

Select TWO CUP for most all cups as this works best.

Reset the cup size to #2

Yes you programmed it unaware, the machine will follow what you instruct on it. So change the program setting and try it again.
This advice will gonna help you.

Try to find a recipe book for automatic breadmakers/breadmachines online or from Amazon etc. In order to determine loaf size just get a measuring vessel that shows the number of cups on the side and keeping track of how many cups it takes to fill your bread pan start adding water to your bread pan. Once it is full to the top comment back as to how many cups it held and I will tell you the loaf size of your machine.
I could not locate an Oster 4843 manual but I do have a Oster manual for another model I could send you a link too. If this was helpful please give me a rating.

Program quantity is trying to program that amount.
When it starts to brew and gets to the quantity you want for that cup size push the brew button again and see if it stops.

Another good solution, though the previous one was good, is that you can factory reset the cup sizes. All you have to do is switch the machine off, and then press and hold the large cup button. After about 10 seconds, keeping your finger on the large cup button, switch the machine on -- then let go of the large cup button after about two more seconds.

Yes, you can adjust the sizes and aroma according to your taste,just hold the the product without releasing your finger,the screen will show programming.Then follow the instructions on the screen. Easy.

Hi
To program the machine for brew quantity, Just hold the button down the whole time,(do not release) As it is dispensing liquid, when you get to the desired quantity, release the button. You can do this for each cup size.