How to calibrate a Bunn CWTF commercial coffee brewer

Depends where in the world you are and how big your cup is.

Recipes were designed to use cups as a measure because as long as the same cup was used the proportions remained the same regardless of the cup size and each recipe could be followed exactly.

Interfering busybodies ruined a perfectly good system by deciding a cup should be approximately half a pint or 8 fluid ounces, a good deal larger than the average teacup and as you will see in the chart of new-fangled measures below, they decided a teacup is actually half a cup...

I think you should now be equipped to answer your own question...

Dry & Fluid Measures Unit Abbrev. Defined fl oz mL
[note 1] Binary Submultiples drop dr., gt., gtt. (plural) 1?96 tsp 1?576 smidgen smdg., smi. 3?128 tsp 1?256 0.115522 2 smidgens = 1 pinch pinch pn. 3?64 tsp 1?128 0.231043 2 pinches = 1 dash dash ds. 3?32 tsp 1?64 0.462086 2 dashes = 1 saltspoon saltspoon or scruple ssp. 3?16 tsp 1?32 0.924173 2 saltspoons = 1 coffeespoon coffeespoon 3?8 tsp 1?16 1.84835 2 coffeespoons = 1 fluid dram Fluid dram [note 2] 3?4 tsp 1?8 3.69669 2 fluid drams = 1 dessertspoon (Australia) teaspoon (culinary)[note 3] tsp. or t. 1?3 tbsp 1?6 4.92892 2 teaspoons = 1 dessertspoon dessertspoon [20] dsp., dssp. or dstspn. 2 tsp 1?3 tablespoon tbsp. or T. 1?16 cup 1?2 14.7868 2 tablespoons = 1 fluid ounce fluid ounce fl.oz. or oz. 1?8 cup 1 29.5735 2 fluid ounce = 1 wineglass wineglass wgf. 1?4 cup 2 59.1471 2 wineglasses = 1 teacup gill or teacup tcf. 1?2 cup 4 118.294 2 teacups = 1 cup cup C 1?2 pint 8 236.588 2 cups = 1 pint pint pt. 1?2 qt 16 473.176 2 pints = 1 quart quart qt. 1?4 gal 32 946.353 2 quarts = 1 pottle pottle pot. 2 qt 64 1892.71 2 pottles = 1 gallon gallon gal. 231 in3 128 3,785.41 2 gallons = 1 peck

first, delime the sprayhead and the trough drain in the top with a flathead screwdriver to ensure maximum flow. next, you'll need a measuring cup or bucket that goes up to 64 ounces. then follow the instructions on the front panel

if it's actually boiling, replace the high temp limit fuse on the top of the tank on the inside rear of the brewer. may be stuck shut. if it's just overflowing the container, recallibrate by using a 64 ounce measuring cup and the instruction on the inside of the front panel

you'll have to recallibrate. use a 64 ounce measuring cup and follow the instructions on the inside of the front panel.

You should be able to pick up a replacement/new pot at your nearest Restaurant Supply store. Make sure you get a 64 oz./ 1/2 gallon pot.
Before plugging in your brewer, unscrew the sprayhead located just above where the filter basket sits and replace the basket, pour 3 pots of cold water through the opening on the top if the brewer is empty. This brewer has a reservoir that holds about 2 1/2 pots of water at brewing temperature when heated. Make sure you put an empty pot under the filter basket after pouring in the water. Water will flow from the brew basket when the reservoir has reached its capacity. Once water flows you can then plug in and energize your brewer and replace the sprayhead. It will take about 15 to 20 minutes for the brewer to reach brew temp, you will hear the heating stop. Put an empty filter and a dose of coffee (I recommend starting with a heaping measuring cup of drip ground coffee) into the filter basket, lightly shake it level, replace the basket and pour through 1 full pot of COLD water in the top. For best results pour the brewed coffee into a pre-heated thermal server if you plan on holding the coffee for more than 10 minutes or so.
Enjoy!