I have a bunn auto brew w/2 warmers.flow control/filter is installed and the basket overflows...

This brewer has a 2 1/2 pot reservoir. You should NOT plug in the brewer before the reservoir has been topped off. Pour 3 pots (one at a time, every minute or so) through the screen with a pot under the filter basket. Wait until the water flows from the basket and only then is it safe to plug in the brewer. The reservoir holds HOT water until you are ready to brew and then, by pouring in a pot of cold water, you will be able to brew.

Please call Bunn Customer Service. There is a different sprayhead that can be used to prevent this problem from happening and is free of charge.

Make sure your sprayhead is the proper one (5 hole) and in good shape. Also make sure that the hole on your filter basket has not been partially closed. This can happen if you set it on the hot warmer. As a last resort, you can slightly enlarge the hole in your filter basket.

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. Don't overfill the 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. Make sure 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.

Some people also try adding fresh grounds to brewed grounds, resulting in an overflow. A restricter valve can be used, but a better solution is to simply pour in half the water at a time. This is what people who buy non Bunn filters do to stop overfills.

Do you grind your beans at home before brewing or is it ground from the store. If you grind just before brewing check her grind and compare it with yours.
Also check to see if she levels the coffee in the basket. Usually when a pot overflows it is because of the grind or the way the coffee sits in the basket.

COFFEE PREPARATION PROCEDURES
1) Place filter into brew basket.
2) Put the proper amount of coffee into the filter.
3) Slide the brew basket into holder.
4) Place empty decanter on warmer located directly under the brew basket and turn corresponding warmer switch ON.
5) Pour decanter of fresh water through pour-in opening at top of brewer.
6) Hot water will be delivered through the sprayhead. This distributes the hot water evenly over the coffee bed within the brew basket. The coffee will drain from brew basket into the container below.
7) Red light indicates warmer is ON.
8) Before brewing next pot, remove brew basket from brew rails and dump filter into waste basket.

Please rate this a fixya

I had the same issue, poured in 8 and out came 6. Here's what I did to clean and fix.
1) Unplug the NHB
2) Remove accessories like the pot and basket
3) Bring NHB over to the sink
4) Snap off the entire top cover (not the swing lid) by starting at the front and lifting upward (the top cover is about 1/4" thick). The back of the top cover will pivot a bit and then pop off exposing the pour reservoir. Remove the flow stopper inside the pour reservoir by lifting it straight up.
5) Place the top cover and flow stopper aside.
6) Remove the brew diffuser (located underneath the top where the brew basket goes. Twist counterclockwise gently but forcefully enough to snap it past the lock tabs which hold it in place. You'll know that it you've done this correctly when it just falls out.
7) Still over the sink, tip the NHB in a fashion where the back side is facing upward and the brew side is facing down into the sink. You'll be holding the NHB horizontally by the top and bottom of the unit. This will allow any water in the tank to pour out the brew spout. Begin to tip the unit as if tipping upside down as this will allow any remaining water to drain out. If this does not work the brew spout hose may be clogged and you can just tip the unit entirely upside down to empty it from the fill hole in the pour reservoir.
8) Return the NHB to the upright position in the sink.
9) Using a scotch brite sponge and some baking soda, clean the inside of the pour reservoir and rinse.
10) Using the tool Bunn provided, clean out the brew spout hose which is located under the brew hat. This is the little hole where the water comes out. If you don't have the tool Bunn provided you could use something like a plastic tie-wrap. Don't use anything metal as the hose you're cleaning is made of plastic tube and could become punctured. Clean this hose for just a minute or two to ensure that there are no significant obstructions.
11) With the NHB upright in the sink, pour a slow stream of hot water from the faucet, about two cups, directly into the fill hole located in the pour reservoir.
12) Tip the unit horizontally, as in step 7, and place the tip of your finger over the pour reservoir fill hole covering it completely.
13) Shake the unit back and forth horizontally so the water in the tank splashes around and frees anything which may be built up in the tank. Some water may splash out of the brew spout hose.
14) Tip the unit as in step 7 to drain the tank water out.
15) Fill a 16 ounce glass with hot water and 2tbsp baking soda, mix and pour into the pour reservoir fill hole.
16) Repeat steps 13 and 14 once.
17) Repeat steps 11 through 14 three times.
18) Clean the pour reservoir cover, swing lid and flow stopper.
19) Put the flow stopper back in place.
20) Attach the top cover.
21) Clean the exterior of the NHB.
22) With the boil and warmer switches off, plug the NHB into the electrical outlet.
23) Turn the boil and warmer plate switches on.
24) Fill the NHB with one pot of cold water and close the swing lid. Wait one minute.
25) Fill the NHB with another pot of cold water. Place the pot on the warmer plate and close the swing lid. If water does not yet come out, fill with one more pot of water.
26) Allow water to drain from brew spout until it stops draining.
27) Empty pot.
28) Fill pot to 10 cup line and pour into the NHB. You should find that the NHB now delivers 10 cups back to the pot. Empty the pot.
29) Clean brew spout diffuser and replace back in the brew hat.
30) Clean the pot, pot lid and brew basket.
31) Wait ten minutes for the water in the tank to boil.
32) Brew your coffee as you normally would.

The only issue I experienced during this process was with the warmer plate switch. It appeared that the light in the switch blew although the warmer plate still warmed normally. Shortly after the water in the tank started boiling the warmer switch light started operating again.