Bunn Dual Wamer not keeping coffee warm

Couple of ideas.

Your weak coffee could be due to the machine not getting hot enough, which is usually caused by calcium scale buildup on the heating element (the "burner").

Try descaling with a citric-acid based cleaner, such as Dezcal or Durgol.

The second is the coffee your using is a weak blend. Try changing to a different coffee and see if the strength is better.

There are two heaters in a VRP unit (Pour over style) The brewer has a tank that your last office person poured in a full pot of water. The main heater senses the colder water and begins to reheat the water to near boiling. The new water pushes out the same amount of water into the brewing basket (funnel with coffee). Once the new water has come up to temperature then the main heater turns off. There is a warming blanket around the inside tank. This keeps the water hot and ready to brew. It uses less power than the main heater. If this blanket fails then the water will cool down to a point where the main heater heats everything back up. You may not notice this as the only indication is luke warm coffee on a freshly made pot or a 'boiling' noise every 15 - 25 mins. This VRP probably needs servicing (check Thermal blanket and Thermal fuse)

Sounds like the hi-limit thermostat on the boiler is damaged, also check to make sure thermostat is set correctly.

Check the Hi-limit thermostat on top of the tank, then the pressure stat setting and then the inline fuse and then elements.

The brewer has not had enough time to reach its operating temp (usually 7 mins after a brew cycle). If that is not hte case then the machine needs to be descaled.

Sounds like the thermostat is bad.

Best to contact a local Bunn service dealer for repair

We left vinegar in the coffeemaker overnight. Seems to have done the trick - water is heating up now after 20 or so minutes instead of several hours.

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.

You can either replace the warming element with a new one, or some people put 3 or 4 pennies on the top of the warmer tray. Don't laugh- this really does work!

Try connecting two elements in series. See if this keeps it hot enough. (One switch controlling both burners.) See if another brand of burner will fit in the hole. Check to see if the wattage is lower.