Bunn Pour O Matic 2 warmer. Pour in water and will run water out into carafe. I plug in and it boils and will make one pot of coffee but does not stop boiling. Boiling out sides and top. Help.

Due to UL regulations, warmer plates can't be sent out. However, you warmer plate can be repaired for a minimal charge. Please call customer service with the model and date code and we will be happy to provide you with the cost and address.

You must change the thermostat.

before plugging in place your empty filter basket in the coffee maker and place a pot under it. Slowly pour in two pots of water using the pour pitcher. Now you can plug it in. it'll take 15 min to heat up first time . when you brew your first pot leave your water level a little short,because the water will expand (only the first time)

It sounds like there is some build up in the brew line, find the nearest bunn dealer and get a delimming spring, then remove the shower and run spring through brew line.

open the cover on the brewer- depending on your model, it could be the front or the back cover. look for a brew timer dial. turn this up slowly, running a brew each time to see if you now have a full pot

You could have scale building up on the heating element and thermostat probe. try running a 1/3 white vinigar - 2/3 water mix into the brewer, let it heat up completely, then run several pots of clear water through the unit. keep pouring water through it until the vinigar smell is out of the water,

If you still have warranty on the machine take it in to the nearest service center.
Its probably a lose pipe in the machine. so if you dont have warranty left just open it up and look for lose pipes and reconnect them.

FOLLOW LINK

I had the same issue, poured in 8 and out came 6. Here's what I did to clean and fix.
1) Unplug the NHB
2) Remove accessories like the pot and basket
3) Bring NHB over to the sink
4) Snap off the entire top cover (not the swing lid) by starting at the front and lifting upward (the top cover is about 1/4" thick). The back of the top cover will pivot a bit and then pop off exposing the pour reservoir. Remove the flow stopper inside the pour reservoir by lifting it straight up.
5) Place the top cover and flow stopper aside.
6) Remove the brew diffuser (located underneath the top where the brew basket goes. Twist counterclockwise gently but forcefully enough to snap it past the lock tabs which hold it in place. You'll know that it you've done this correctly when it just falls out.
7) Still over the sink, tip the NHB in a fashion where the back side is facing upward and the brew side is facing down into the sink. You'll be holding the NHB horizontally by the top and bottom of the unit. This will allow any water in the tank to pour out the brew spout. Begin to tip the unit as if tipping upside down as this will allow any remaining water to drain out. If this does not work the brew spout hose may be clogged and you can just tip the unit entirely upside down to empty it from the fill hole in the pour reservoir.
8) Return the NHB to the upright position in the sink.
9) Using a scotch brite sponge and some baking soda, clean the inside of the pour reservoir and rinse.
10) Using the tool Bunn provided, clean out the brew spout hose which is located under the brew hat. This is the little hole where the water comes out. If you don't have the tool Bunn provided you could use something like a plastic tie-wrap. Don't use anything metal as the hose you're cleaning is made of plastic tube and could become punctured. Clean this hose for just a minute or two to ensure that there are no significant obstructions.
11) With the NHB upright in the sink, pour a slow stream of hot water from the faucet, about two cups, directly into the fill hole located in the pour reservoir.
12) Tip the unit horizontally, as in step 7, and place the tip of your finger over the pour reservoir fill hole covering it completely.
13) Shake the unit back and forth horizontally so the water in the tank splashes around and frees anything which may be built up in the tank. Some water may splash out of the brew spout hose.
14) Tip the unit as in step 7 to drain the tank water out.
15) Fill a 16 ounce glass with hot water and 2tbsp baking soda, mix and pour into the pour reservoir fill hole.
16) Repeat steps 13 and 14 once.
17) Repeat steps 11 through 14 three times.
18) Clean the pour reservoir cover, swing lid and flow stopper.
19) Put the flow stopper back in place.
20) Attach the top cover.
21) Clean the exterior of the NHB.
22) With the boil and warmer switches off, plug the NHB into the electrical outlet.
23) Turn the boil and warmer plate switches on.
24) Fill the NHB with one pot of cold water and close the swing lid. Wait one minute.
25) Fill the NHB with another pot of cold water. Place the pot on the warmer plate and close the swing lid. If water does not yet come out, fill with one more pot of water.
26) Allow water to drain from brew spout until it stops draining.
27) Empty pot.
28) Fill pot to 10 cup line and pour into the NHB. You should find that the NHB now delivers 10 cups back to the pot. Empty the pot.
29) Clean brew spout diffuser and replace back in the brew hat.
30) Clean the pot, pot lid and brew basket.
31) Wait ten minutes for the water in the tank to boil.
32) Brew your coffee as you normally would.

The only issue I experienced during this process was with the warmer plate switch. It appeared that the light in the switch blew although the warmer plate still warmed normally. Shortly after the water in the tank started boiling the warmer switch light started operating again.

The pour-over type of Bunn coffee brewers require several pots of water to fill an empty tank.
1. While unplugged, pour in two and a half to three pots of clean water (put an empty pot underneath the brew basket). When the tank is full, water will come out of the brew basket.
2. Plug the unit in and wait for it to heat - about 5 to 7 minutes. These brewers are meant to be left plugged in all of the time to keep the tank water hot. You will probably heat some rumbling noises which is normal as the water heats.

If for some reason the water isn't hot after 10 minutes you will need to check the thermostat. Unplug the machine and take the screws out of the top. The thermostat has a little dial or a t-bar that you can turn. All the way left is off and all the way right is boiling. Turn this up about 90% of the way and put the top back on the machine and plug it in. If it gets hot, you are ready to brew. If it doesn't get hot, you may have blown the limit thermostat and will need to replace it.

The limit thermostat isn't the same as the thermostat. It is a ceramic and metal item that senses if the tank gets too hot from having the unit plugged in without any or enough water in it. It is inexpensive and relatively simple to change.