Replies to This Discussion

Permalink Reply by Bob Von Kaenel on November 10, 2010 at 8:41am

Our Bunn makers, (airpot brewers model CTWF), will occasionally, like once a month, just starting blowing out steam and water without warning. It will definitely freak you out the first few times it happens. It's really not big deal, just get something in place quickly to catch the water. I never really knew why they do it but it seemed like the thermostat might have just gotten stuck and overheated the water until the over-pressure release valve let loose. We always just hit the button to run a batch of water and it always goes back to normal operation after that.

• ▶ Reply

Permalink Reply by Julie MacDowall on November 10, 2010 at 8:53am

Hi Bob,

Thanks for the quick response. Previous owner had a Bunn ICB Twin that would occasionally
blow water and steam and it was such a violent release once that water got into the circuitry and
fried the board (causing a small fire). We bought the business and repaired the Bunn but used
our backup Fetco CBS 2032 and had it happen to this machine.

We recently purchased a very new Fetco 2032s and are afraid that this one will fry too...Equipment
is too expensive to keep blowing up!



Bob Von Kaenel said:

Our Bunn makers, (airpot brewers model CTWF), will occasionally, like once a month, just starting blowing out steam and water without warning. It will definitely freak you out the first few times it happens. It's really not big deal, just get something in place quickly to catch the water. I never really knew why they do it but it seemed like the thermostat might have just gotten stuck and overheated the water until the over-pressure release valve let loose. We always just hit the button to run a batch of water and it always goes back to normal operation after that.

• ▶ Reply

Permalink Reply by Brady on November 10, 2010 at 10:51am

The Fetcos and Bunns I'm familiar with don't have an overpressure valve like there is on an espresso machine, just an overflow tube. On most, this tube runs down to a little port in the brew basket area.

What is your thermostat set to? If it is near the boil, small fluctuations may cause it to randomly boil. Check the temp of the water inside the tank with a good accurate thermometer and drop your set temp just a bit if it is too high.

On the Bunn CWTs (thermal pourovers) that have been plumbed in, water overflowing can be due to water pressure being too high. These ship with pressure reducers on the back, but sometimes they get lost when sold used.

There could be a number of things that cause your brewer to overheat or overflow. Time to call a tech.

• ▶ Reply

Permalink Reply by Julie MacDowall on November 10, 2010 at 11:04am

Thanks Brady...

We were actually on the phone with Fetco for an hour today...not much insight there.
We have all techs on deck for Friday morning. I will post results for those who experience
this problem.

Someone mentioned that because our coffee is so fresh and we grind right before brewing that perhaps the gases in the coffee are causing an increased bloom. Not sure if thats the case. What do you do?
Pre grind and let rest or grind for each air pot before brewing?


Brady said:

The Fetcos and Bunns I'm familiar with don't have an overpressure valve like there is on an espresso machine, just an overflow tube. On most, this tube runs down to a little port in the brew basket area.

What is your thermostat set to? If it is near the boil, small fluctuations may cause it to randomly boil. Check the temp of the water inside the tank with a good accurate thermometer and drop your set temp just a bit if it is too high.

On the Bunn CWTs (thermal pourovers) that have been plumbed in, water overflowing can be due to water pressure being too high. These ship with pressure reducers on the back, but sometimes they get lost when sold used.

There could be a number of things that cause your brewer to overheat or overflow. Time to call a tech.

• ▶ Reply

Permalink Reply by Greg Hill on November 10, 2010 at 3:10pm

fetcos and newer bunns have a dump valve and do not work like your standard bunn. if you have water coming out of the sprayhead (not the overflow valve off to the side) you need a valve kit or a cleaning of the valve. if the water is coming out of the little hole behind the sprayhead, the problem could be with the fill valve or fill probe. if the brewer doesnt generate a fill error, its a leaky fill valve.

all brewers will sometimes blow out extra water under heavy usage. all that cold water coming into the tank will expand as it heats and come out either the overflow or sprayhead (depending on the brewer.) this happens much more often on brewers without cold brew lockout or lockout disabled.

also, i have never seen a fetco extractor series send water to where its not supposed to be.

• ▶ Reply

Permalink Reply by Brady on November 10, 2010 at 3:13pm

Is it overflowing filters? If so, you may be using the wrong one.

You should not have to grind in advance to prevent overflow.

These brewers tend to be quite robust and easily repaired by a qualified technician. They will occasionally break (as all things do), but when they do they are repairable. Short of failed weld on a reservoir or being dropped (or used as a stepladder to erase the menu board - seen it) these things can generally be repaired pretty quickly and easily.

Please let us know what your tech finds out.

• ▶ Reply

Permalink Reply by Jason Shipley on November 10, 2010 at 6:19pm

Very fresh coffee and softened water with too much sodium content will cause the grounds to violently overflow. On the CBS2032 you can play with the prewet percentage and dwell time to help the situation. As far as random water dumps we had some issues untilled I upgraded to their cascading spray domes.

• ▶ Reply

▶ Reply to Discussion