How to fix a Bunn NHBX that produces warm, not hot, coffee?

SOURCE: Warming plate boils coffee.

Make sure you are using the type of commercial coffee pot like the one in the picture. They don't have to have to be plastic with the metal bottom, they can be all glass. The commercial pots are heavy duty and usually disperse the heat well.

If you are using commercial pots the only solution without replacing the warmers is to put three pennies on the warmer and to put the pot on top of them. The pennies will get hot so don't forget and grab them but the pennies help to move the pot just a little way away from the direct heat.

SOURCE: bunn coffee maker

It sounds like you have a pour over model and the problem is the tank isn't full. Turn the machine off (or unplug it). Put a pot on the warmer like you are going to brew coffee. Pour clean cold water into the top until it starts coming out the sprayhead (above where the coffee grounds go). Now plug it in and turn on. Let it heat up then you can brew.

The way your machine works is that there is always about 2-1/2 pots of water in the tank. The water you pour in to make coffee is actually pushing the hot water in the tank out. So, if you don't fill the tank before using it, you may be hurting the heating element since it isn't totally submerged in water.

SOURCE: bunn commercial coffee maker plug overheats, no hot water

Most likely this is your heating element, but it could also be your main thermostat

SOURCE: No manual with Bunn NHBX coffee maker.

Leave the unit unplugged and add a carafe of water to the top reservoir.
Close the lid.
Wait a bit to make sure the water has drained into the tank.
Add another carafe of water to the top reservoir.
Place carafe on warmer plate.
Close the lid.
When water stops going into the carafe, you may plug the machine in and make sure the "travel switch" is in the ON position. ON = |, OFF = O.
Wait at least 15 minutes for the water in the tank to heat up, and brew as you normally would for other BUNN coffee makers.

SOURCE: I have a bunn coffee maker the NHBX is the # it is

Please give Customer Service a call with the model and date code. If the machine is 3 years old or less, it will be replaced with a new machine. If it is older than 3 years, it can be exchanged for a reduced price.