Bunn Coffee maker

SOURCE: my bunn is too slow

Use the de-liming spring to clean the copper tube behind the spray head. Pour several pots of clear white vinegar through the unit to further remove lime and scale from the interior of your coffee maker. My Bunn is 24 years old, and the only replacement parts I've ever required are new carafes and the 4041 silicone washer repair kit.

SOURCE: Bunn coffee drips slow

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.

SOURCE: my bunn coffee maker leaks

You need to replace the washer kit inside the top of the maker. Remove the 3 screws that fasten the top and lift it off. You will see the rocker leaver that allows the water to flow into the tank. At the point where the rocker stops the water there is a series of washers that degrade from the heat over time and allows the leak. The washers are very easy to replace. The problem is finding the washer kit. I found it at: www.buyitnow64.com for $3.95 plus shipping (FedEx is only $9.98). I bought 2 (one for backup) kits.The original washers lasted almost 6 years. I had repaired this problem before with a washer from my shop but it broke down rather quickly from the direct heat from the tank. This washer kit is a Bunn washer kit that is supposed to fit all Bunn machines both residential and commercial.
Hope this helps. It took me 2 hours on line to find the washers!