A Bunn coffee pot may leak due to improper care and maintenance or regular wear and tear, including the breakdown of seals and gaskets within a brewer that naturally occurs over time. An accumulation of mineral deposit from water could also cause leaks.
Regular cleaning helps keep a Bunn coffee pot from leaking. According to Bunn.com, different models are prone to particular issues. The Bunn Velocity brewer is not meant to hold water in its top tray for extended periods of time, including overnight. The Phase Brew may have mineral deposits clogging its Pour In Bowl and require cleaning. The trifectaMB from Bunn may have coffee particles or oils in its brew chamber valve, which causes water leakage.