I have a Bunn CWTF15. Water does not fill the coffee pot full anymore. Is there a float that needs to be adjusted? Would descaling help this problem? Thank you.

You should call your vendor for service on any commercial brewer. (Especially if it's on loan from them)
*** the following is for information only as all repairs should be performed by a qualified tech.***

The CWTF has a start switch activates the timer (analog or digital) board which turns on the water feed to the brew tank. This forces previously heated water out and sprayed over the ground coffee in the brew funnel. Coffee then drips into the decanter. Under filling is caused by un-calibrated timer or interment timing.
* The timer comes in two types; Dial (old) and Digital. If it's the dial then a simple turn of the dial will make less or more water flow to decanter. You MUST re-brew (no coffee, but use funnel) into the decanter or pot that you plan to use. Don't mix up different size pots as the timer is only good for 1 setting. Turn dial and brew once to check. Keep checking with a brew after each adjustment. Do a final brew just to be sure.
* The digital timer is a bit more complicated to adjust. Sorry, too many switches and options to go into it here. Check Bunn.com for a manual (FREE download) on line. Several methods are listed. The fill and stop is the easiest one.
* If it does not adjust or won't keep the set time then. Replace the timer. Digital timers tend to be sensitive to electrical storms. Analog timers have a dial and are more tolerant of electrical surges.
* Check the water fill solenoid. Should be a definite click when activated. Water filling sound should be very clear.
* No water flow then check the water supply line if it's on.
* Final; this brewer needs service. Call your coffee vendor for advice.
Aloha, ukboy57

P.S., Older timers usually are reliable. It may have been set for a larger decanter or pump pot. The pump pots come in 2.5L and 3L for the big boys. Decanters are 10 cup and standard 12 cup. Check your office as there may be an unused pump pot or small decanter in a cupboard that got put away for making "too little" coffee. Try a brew in this smaller pot. Any change in pot size requires an adjustment to the timer. This is the only way to get "Less" or "More" out of the brewer. (Yes there is a way to use the "Pour Over" function for one time special brews. Check the manual for this option.)

If u haven't cleaned it out using 3/4 vinegar to 1/4 water, some times this will happen. after running this thru ur coffee maker, (u won't believe the junk that comes out), then run full pots of water to rinse out (2x's). This should help it perform better.