Bunn coffeemaker leaks cold water from bottom?

The NHS-B has a semi-sealed tank that keeps +1 pot of water heated and ready to brew. Pouring in a full pot of cold water will fill the top tray and allow a slow trickle of cold water into the top which forces hot water to over flow into the brew basket. This continues until all the cold water drains into the heater tank. So the brew is matched volume per volume. UNLESS the thank was empty or not filled prior to brewing. Follow the brewing instructions from Bunn (on line for *FREE* download at Bunn.com)
* If it leaks (from the bottom) only when you pour in water. Then your pouring it too fast and over flowing the fill tray. slowdown, watch the level in the tray. do not fill past the lid.
* If it leaks just sitting (not brewing) then there is a hole in the tank. Call for service.
* If it leaks after filling the tray half way. then the top of the tank has a leak, loose, cracked, or missing gasket. There is quite a few gaskets on the lid. Call for service.
* Final; Leaks are always bad around electrical equip. Best to unplug and call for service to be safe.
Aloha, ukeboy57

P.S. If you did splash too much water then wipe up as much as you can. Leave it out on a towel or paper towels to allow the excess moisture to evaporate. If you dump all the water out of the brewer (and tank) then you will need to pre-fill it with a pot of water PRIOR to plugging in the brewer. Follow the set up instructions in the manual. Let it heat up and try again. If it's still leaking then there is a hole in the tank. Call for service.

after nearly 8 years of service a water leak shorted the heating element and the short caused a small metal thermal fuse to open

Tank and tank components should be delimed regularly
depending on local water conditions. Excessive mineral build-up
on stainless steel surfaces can initiate corrosive reactions resulting in serious leaks.

If you will call 800-352-2866 with the model and date code and we will be able to help you resolve your issue.

The brewer probably has a bad seal or gasket. By the date code, your machine is 5 years old. If you call Bunn Customer Service they will be able to offer you an exchange of your old brewer for a new one at a reduced price.

If you will call Customer Service with your Model and Date Code located on the bottom of the brewer, we can assist you with this problem.

If you can provide the date code located on the bottom of the brewer, I will be happy to offer a solution to your leaking problem.

Sounds like a leaking water pipe from the water source, unless you have a over temp heater and this results in steam and dripping.

you can always clean a coffeemaker with vinegar, but always pour in cold, so you can do it twice or more, but dont re-use the stuff you just used, wait till it's cold or just use some other.after use clean by let water through 2 or 3 times, (also only cold water)

Hook it up to cold water. It has a heating element in the tank that heats the water.