When brewing the coffee at times the water stays and almost overflows where the filter and coffee is rather than brewing properly- what could this be and how to fix it?

I assume this is a drip coffeemaker using a drip filter. If so, does it grind the grounds or do you add them? Are you using a paper filter or the gold one? Try a coarser grind and make half a pot. Then check level of brewed grounds. Never use a gold and paper filter together.

These tanks can't actually be overfilled since all water poured in displaces the exact same amount of water coming out the spout. So, whatever amount of water you pour in, will be the same amount of water that flows to your pot minus the amount absorbed by the coffee grounds and filter.

Your problems sounds like an undersized (Non Bunn) filter, or clogged brew basket. To verify this, try pouring in only half the water for your brew cycle and wait for it to finish dripping, then pour in the rest. If no overflow has occurred, you simply have the wrong type of filter. If overflow begins again, you have a clogged brew basket, since no Bunn can flow too fast for the brew basket to keep up with it.

This is because Bunn filters are manufactured differently than generic store bought paper filters. They will flow faster, brew cleaner and stand up better than normal generic filters.
Remember, Bunn makes their OWN filters for good reason.
They made the first, best paper filters for drip coffee pots, and all others are just generic dioxin gas producing paper.

Coffee overflowing onto the counter is a common complaint found in response to many automatic drip coffee makers. The following are potential solutions that can be used to rule out "operator error" vs. a defect or malfunction:

1. Do not "pack" or otherwise overfill the cone/basket with grinds.
2. Ensure you are using the correct grind for an automatic drip coffee maker, neither too fine nor too course. (See instruction manual and/or do an Internet search for tips.)
3. Do not overfill with water. Use the carafe to pour water into the reservoir, and the lines on the side of the indicator window as your guide. This is because a "cup" in coffee terms is defined as 6 oz, not 8 oz. Therefore, a 12-cup machine may make as few as nine 8 oz mugs of coffee.
4. Make sure the filter cone/basket clicks into place and that the carafe is centered and pushed all the way in.
5. Try a permanent filter rather than a paper filter or vice versa.
6. Only use the correct permanent or paper filter (see manual).
7. Verify that the Pause 'n Serve feature, if applicable, isn't sticking. If it is activated too long the brew will escape over the top of the cone/basket. This may be more apt to happen if the alignment of the carafe and the basket is incorrect.
8. It is vitally important to clean your machine with vinegar or as instructed by your user manual at least three times per year and monthly if under heavy use in a hard-water area. A properly cleaned machine is less likely to suffer a burned out heating element, to take too long to brew, to produce "off" tasting coffee, or to clog and overrun the filter basket as the water runs through the grinds.
9. Ensure that the coffee machine is sitting level on the counter.

The two most common reasons for overflow or underflow have to do with the carafe lid and the filter basket - they key to smooth flow with this coffee maker is making sure the filter basket and carafe lid are making the proper contact with each other so that the center knob on the carafe lid pushes slightly up on the filter basket spring. Make sure the carafe lid is completely closed. Make sure the filter basket is pushed all the way down. Make sure you are not using the gold tone filter and a paper filter at the same time. For some reason, I get better results when the handle of the carafe is resting against the right side wall. If everything is in place, I would suspect a problem with either the filter basket being clogged or some problem with the carafe lid - call Cuisinart as they should be able to order these parts for you.

Coffee overflowing onto the counter is a common complaint found in response to many automatic drip coffee makers. The following are potential solutions that can be used to rule out "operator error" vs. a defect or malfunction:

1. Do not "pack" or otherwise overfill the cone/basket with grinds.
2. Ensure you are using the correct grind for an automatic drip coffee maker, neither too fine nor too course. (See instruction manual.)
3. Do not overfill with water. Use the carafe to pour water into the reservoir. This is because a "cup" in coffee terms is defined as 6 oz, not 8 oz.
4. Make sure the filter cone/basket clicks into place and that the carafe is centered and pushed all the way in.
5. Try a permanent filter rather than a paper filter or vice versa.
6. Only use the correct permanent or paper filter (see manual).
7. Verify that the Pause 'n Serve button isn't sticking. If it is activated too long the brew will escape over the top of the cone/basket. This may be more apt to happen if the alignment of the carafe and the basket is incorrect.
8. Clean your machine with vinegar or as instructed by your user manual at least three times per year, more if your water supply is hard. A properly cleaned machine is less likely to suffer a burned out heating element, to take too long to brew, to produce "off" tasting coffee, or to clog and overrun the filter basket as the water runs through the grinds.
9. Ensure that the coffee machine is sitting level on the counter.

Coffee overflowing onto the counter is a common complaint found in response to many automatic drip coffee makers. The following are potential solutions that can be used to rule out "operator error" vs. a defect or malfunction:

1. Do not "pack" or otherwise overfill the cone/basket with grinds.
2. If self-grinding your coffee beans, ensure you are using the correct grind setting for an automatic drip coffee maker. (See instruction manual for coffee maker and/or grinder.)
3. Do not overfill tank with water. Use the marks on the side of the reservoir as a guide rather than those defined by another measuring method. This is because a "cup" in a coffee carafe is defined as 6 oz, not 8 oz, and in some cases as little as 5 oz as a cup. As such, a 12-cup machine actually produces closer to 9 standard 8 oz cups. (See your owner's manual.)
4. Make certain the filter cone/basket clicks into place and that the carafe is centered and pushed all the way in.
5. Try a permanent filter rather than a paper filter or vice versa.
6. Only use the correct permanent or paper filter (see manual).
7. Verify that the Pause 'n Serve button isn't sticking. If it is activated too long the brew will escape over the top of the cone/basket. This may be more apt to happen if the alignment of the carafe and the basket is incorrect.
8. It is extremely important to clean your machine with vinegar or as instructed by your owner's manual at least three times per year, more if your water supply is hard (prone to leaving water rings). A properly cleaned machine is less likely to suffer a burned out heating element, to take too long to brew a pot of coffee, to produce "off" tasting coffee, or to clog and overrun the filter basket.
9. Ensure that the coffee machine is sitting level on the counter.

Coffee overflowing onto the counter is a common complaint found in response to many automatic drip coffee makers. The following are potential solutions that can be used to rule out "operator error" vs. a defect or malfunction:

1. Do not "pack" or otherwise overfill the cone/basket with grinds.
2. Ensure you are using the correct grind for an automatic drip coffee maker, neither too fine nor too course. (See instruction manual.)
3. Do not overfill with water. Use the carafe to pour water into the reservoir. This is because a "cup" in coffee terms is defined as 6 oz, not 8 oz. Note: Some coffee makers define as little as 5 oz as a cup.
4. Make sure the filter cone/basket clicks into place and that the carafe is centered and pushed all the way in.
5. Try a permanent filter rather than a paper filter or vice versa.
6. Only use the correct permanent or paper filter (see manual).
7. Verify that the Pause 'n Serve button isn't sticking. If it is activated too long the brew will escape over the top of the cone/basket. This may be more apt to happen if the alignment of the carafe and the basket is incorrect.
8. Clean your machine with vinegar or as instructed by your user manual at least three times per year, more if your water supply is hard. A properly cleaned machine is less likely to suffer a burned out heating element, to take too long to brew, to produce "off" tasting coffee, or to clog and overrun the filter basket as the water runs through the grinds.
9. Ensure that the coffee machine is sitting level on the counter.

If the water is running out the seams in the plastic BEFORE you brew anything, it is a defect or design flaw. I bought one that looks like the one pictured and it did the same thing. So did the replacement.
If the overflow occurs during brewing, verify the following:

Coffee overflowing onto the counter is a common complaint found in response to many automatic drip coffee makers. The following are potential solutions that can be used to rule out "operator error" vs. a defect or malfunction:

1. Do not "pack" or otherwise overfill the cone/basket with grinds.
2. Ensure you are using the correct grind for an automatic drip coffee maker, neither too fine nor too course. (See instruction manual.)
3. Do not overfill with water. Use the carafe to pour water into the reservoir. This is because a "cup" in coffee terms is defined as 6 oz, not 8 oz. Note: Some coffee makers define as little as 5 oz as a cup.
4. Make sure the filter cone/basket clicks into place and that the carafe is centered and pushed all the way in.
5. Try a permanent filter rather than a paper filter or vice versa.
6. Only use the correct permanent or paper filter (see manual).
7. Verify that the Pause 'n Serve button isn't sticking. If it is activated too long the brew will escape over the top of the cone/basket. This may be more apt to happen if the alignment of the carafe and the basket is incorrect.
8. Clean your machine with vinegar or as instructed by your user manual at least three times per year, more if your water supply is hard. A properly cleaned machine is less likely to suffer a burned out heating element, to take too long to brew, to produce "off" tasting coffee, or to clog and overrun the filter basket as the water runs through the grinds.
9. Ensure that the coffee machine is sitting level on the counter.

Replace the filter basket - around $6.00. Make sure lid is seated properly on caraffe. Don't use paper/gold tone filter at same time.