20 Most Recent Bunn-O-Matic Coffee Brewer GRW8 - Page 5 Questions & Answers

Sorry this brewer is usually set up for a full pot brew. I have reset this for a small (but not half) pot brew as the customer wanted to use a metal carafe (with their own logo). I also tried once to get it to half pot brew but it can get tricky if you actually brew twice to get a full pot (in the same pot).
* there is a siphon action that starts once the boiler tank gets filled to a certain point. From that point it will continue to flow until the boiler is emptied to the level that stops the siphon action and leaves enough water in boiler to reheat for the next brew. Achieving the siphon point may be a larger volume of water for 1/2 a pot but may work for 3/4ths a pot. The 1/2 way mark may be affected by the brewers "level" while placed on a table or sagging in the middle of a weak table.
* Usually if you want a smaller brew then go with a smaller brewer. Though there is a hot water tap that will give you 2-4 cups of hot water (it gets tepid after that) which you can use for the "Mug" style brew. But it does get messy.ukeboy57
* Final, If you don't mind a little more than 1/2 pot brews then ask your vendor to adjust the machine for you. Though a reminder NOT the double brew in the same pot as it will overflow.
Aloha, ukeboy57

Bunn Coffee... | Answered on Jan 19, 2018

Sounds like water hammer. There is a small (very small) water hammer minimizer built in the Single and Dual brewers. If your looking at the water valve there is a small 1/4" copper tee with one end sticking upward. This usually has air trapped inside and tries to soften the water pressure as the valve open and closes. There are larger ones mounted in the bigger urns like the U-3 brewers. Though it's easier to have the plumber install a larger one at the mains to take care of the whole restaurant.
* It is possible to replace the copper water line (to the brewer) with a reinforced flex hose that will take up the initial pressure of water hammer but if you are running high water pressure then there is a danger of the hose bursting. Might be better to go with an armored hose (those used under sinks)
* There is one more thing is the water probe is getting too sensitive. Have the tech replace the water level board. He will want to do this as the constant clicking of the water valve will cause it to fail (like in a month or less)
* High pressure can cause sloshing in the tank. This creates waves in the tank but normally the water level board will ignore this splashing on the probe. Have the tech check and clean the probe anyway. It may be possible to reduce the flow rate to the brewer (thus the water hammer pressure) by adjusting the valve that supplies the brewer. Be sure to have the Tech label the valve as someone is sure to come along and open it wide again..
Aloha, ukeboy57

PS; double check if the valve is rated for your water source. Hot water supply requires a different valve (it's bigger too.). Most come with the standard cold water supply rated valve. ukeboy57

Bunn Coffee... | Answered on Jan 19, 2018

* tank overfilling. Shock hazard! Unplug. Check warranty. Call vendor for service or replacement.
* probably a leaking tank, valve, level probe, have tech check.
Aloha, ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

* Thermostat shorted. Unplug. Check warranty. Call vendor for replacement.

Aloha, ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

* Element or thermal fuse blown. Check for warranty and replace.
Call your vendor.

Aloha, ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

Ahh, why? These are really small home units that are not worth the time to fix. It will take an hour to replace to add to the cost of shipping and parts.
* you can find Bunn manuals on-line but go directly to Bunn.com don't get side tacked with "manual" as those sites charge you for the download.
* If your really curious then most of these small brewers have a single element that are usually coiled to fit the bottom of the tank. Most are like this but you may find a few that are U shaped though they are usually found in metal tanks. the plastic tanks keep the elements small and near the bottom to make sure it does not melt the tank if the water is very low.
* The element should be a copper clad tube, sometimes chromed or silvered to give the copper more protection. A used one may be covered with some calcium deposits. Heaver deposits will drop the efficiency and make it harder to remove (thus more labor) Brewers at this level of usage is best if replaced.
* There should not be any holes or "exploded", Ripped cuts in tube as it has a heating wire inside with a white powder to keep it centered within the tubing. If water gets inside it shorts to ground and boils without stopping. this will usually short out the tank and blow the thermal fuse. Either way, lots of damage and more parts to replace.
* Replacement will require all the washers and new lock nuts with a possible tank replacement if it leaks when you removed the element. As mentioned earlier; lots of labor.
* Final; I hope you called your vendor. If still under warranty they will probably just replace the whole unit.
Aloha! ukeboy57

PS. Don't feel bad. I'm a retired tech with nothing but time to type this long reply. Yes I've got a whole garage filled with old machines that need fixing. But who's got the time! LOL

Bunn Coffee... | Answered on Jan 18, 2018

* If this is a pour over (VPR, VPS, etc.) then you must pre fill it then pour in one pot of water to get one pot of brewing hot water out of it.
* If this has an external tank of water then it must be filled and make sure the float sensor works and pops up to indicate a filled tank.
* But most likely this is a CWTF, CW, or larger commercial brewer that has a plumbed in water line. If this is the case then the tank must be pre-filled and heater turned on. usually done by the vendor or installer. It should have been tested and brewed to check water level of brew. Follow the brewing instructions.
* Still not working? Call vendor for service. It could be timer, brew switch, water level board, water fill valve,brew valve. all need check and service to replace as needed. Many larger units have high voltages so call the tech to be safe.
Aloha, ukboy57

Bunn Coffee... | Answered on Jan 18, 2018

The following is for espresso coffee shots but it applies to all coffee brewer and home brewers as you control the beans and water used:
* pour pour, shot, puck, etc. are signs of an improperly prepared espresso. This can be caused by many things but since this is an robotic machine that performs the same time and time again then lets assume for now that the machine is working properly. If the machine is at fault then it will require service from your vendor or directly from the MFR.
* Did you change beans? Poor quality beans are usually easy to spot; Lighter color beans, Multi-color, very oily (shiny ok but not dripping like butter), flavored beans (poor quality bean with flavor added). All automatic espresso or cappuccino machines are expected to have Espresso roast with French roast or at least a Dark roast as the basis for any coffee beverage. Lesser roasts; regular, mild, house roast tend to make a poor cup. Clean out all old coffee and replace with a high quality ESPRESSO roast coffee (Lavazza is a good example) Run machine through 3 or more cycles to flush out old beans and oils. It may take 10 or more cycles so be patient.
* Did you change water source? Since this is a table top machine in which you fill the water tank. Try to use filtered (bottled ok) water. Do Not use Distilled or 100% pure water as this type of water will eat out the metals from your machine! Some places use a water softener as it tends to be better for the machine long term (years).
* Finally; Beans and Water are the two things you can control. If your still having problems then lets look at the machine: Can you reset it to original factory settings? Do so and check results. If it's okay then SLOWLY make your changes one at a time till you get the best result or stop if it gets worst. Note: once set to your liking then DON'T change beans or water as it will change everything. (even a batch of beans can be bad. Stay with a reputable coffee roaster!)
* Still got problems? Check with vendor or MFR for service or replacement. Most machines of this type do not have serviceable parts or adjustments.
Aloha, ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

Should be about 8-15 mins depending how cold the water was. Here are the instructions: Aloha! ukeboy57


Bunn Coffee... | Answered on Jan 18, 2018

* call vendor for service. Brew timer or water level float needs adjustment.
* Make sure your using the correct brew pot for this machine. It's 64 oz decanter if I remember right. Some of the older glass pots are smaller. Especially if it's the roundy one that looks more like a ball. It should hold at least 1 quart of water easily. Ask your vendor for the correct pots (they don''t like you using 'other' brands of coffee if it's printed on the pot.
* Long shot but possible the valve was put in backwards. Either way the vendor should replace it.
Aloha! ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

* Most decanters are made of tempered glass and unless cracked it should not leak.
* Make sure the two pots you are using (one to pour one to brew) is the same size. Check by filling one then pour into the other. If they don't match then get a matching one.
* Most overflowing pots are caused by over filling brewing tank. This can be caused by re-pouring additional water into the brew tank. (automatic brewers may have a leaking water valve - call your vendor for service)
* Partial brewing (taking coffee from a brewing pot) and then putting in more water.
* Removing the pot BEFORE it stops dripping. It leaves a puddle of coffee on the warmer plate
*Over filling the water tank. Most times the extra water will spill out the back. But some may overflow into the basket area then the warmer plate.
* Follow the MFR brewing instructions for filling.
* All brewers should stop water drips after brewing. If you get a constant drip AFTER brewing then have the brewer checked or replaced. Call your vendor.
Aloha, ukeboy57

PS: I've noted that you don't mention the brand nor model of the server you got from Kohls so I'm guessing it might be a dispenser or even a bunn dispenser which is different from a decanter as it has a serving spout. You find these at banquet halls where it's dispensed from a small faucet. You can find similar faucets from bunn.com or most restaurant supply stores as it's a very common item. Amazon.com has them too. the part tat leaks is the rubber boot or worn spring. best to buy the whole faucet and keep the old one for parts as needed. amazon link:

Bunn Coffee... | Answered on Jan 18, 2018

I thought these are pour over brewers? Which means you have to fill it with water in order to brew? It should happen when the unit is filled first, plugged in then turned on.(see link below for MFR instructions) Aloha! ukeboy57


Bunn Coffee... | Answered on Jan 18, 2018

Humm, G-3 grinders. Okay what common problems I've come across:
* Wrong setting for grind on label. Usually means worn out grinder burrs. But this does not happen often unless you are using it to grind commercial amounts of coffee? It's a retail level grinder meant to be user friendly and simple to use. Say grind a bag of beans once every 10 mins or so even with customers lined up to grind there own. Running a G-3 constantly is usually done by upcoming coffee vendors whom are using it for small flavored bean batches. But expect the burr plates to only last 3 to 6 months. We used to change it every month till the boss bought a bigger pro grinder. (whew!)
* Out of calibration (for grind) This usually happens as soon as it's installed. Either the grinder got banged (Dropped?) around or the lock nut was not tighten down. If caught quickly then it's a simple adjustment. Left unchecked will wear out the burrs or crack the plate.
* Trips out breaker. This is common at retail stores as it's located in a shelf rack that really does not have the required outlets. Many times there is a brewer(s) connected to the same line. It only trips out when one or both brewers are heating and the grinder is running a very fine grind.
* Trips out breaker when grinding espresso or very fine grinds. Worn burrs or slim chance the grinder was miss calibrated (but you would catch this when first installed)
* Shocks the customer. Dry climates or heavy air conditioning will build up static electricity at the chute. There usually a small chain attached to the chute to prevent this. Attach a SHORT metal chain or thin cable to the metal case of the grinder and add a metal clip to attach to the coffee bag. Many use a chain and clip just short enough to keep the bag positioned under the chute. Note many coffee bags come with bag clips. Just make sure the clip and chain can't get stuck in the grinder.
* Not working. This is usually the on/off switch as it gets beat up the most. There is sometimes a safety micro switch under the chute to sense if there is a bag there. I've found may have been defeated.
* No power, check cord, breaker (GFRI) outlet, Plug prongs if broken off or bent.
* power but no motor hum. Tripped thermal breaker (usually a red button on side or back. Some models may have it inside on the motor itself. Call for service to check.
* Turns on but loud hum (may be hot too). Burrs stuck. This could be from adjusting grinder while grinding beans and adjusting to a fine setting. Grinding finer slows down the beans feeding the burrs. Large settings flood the burrs with a lot of beans. Adjustments are usually done when the grinder hopper is completely empty. If loaded and turned down from coarse to fine grind the beans already in the burrs get crushed and stuck between the plates thus locking them in. It may be possible to clear the hopper and open up the grinder to its coarsest setting to jog out the crushed beans. Otherwise call for service to have the burrs cleared manually.
*Finally check with your vendor if your still having problems.

Aloha! ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

First, Though I have worked on many Bunn commercial systems. I'm not quite familiar with the newer MCU though I've worked on similar single cup home systems.
* Most single up systems like the Cup/Pod/Capsule usually have a air flusher that pushes all the water out of the brewer to extract all the flavor and prevent old liquids left in unit.
* If your still dripping, have wet pods/capsules/cups, then it sounds like the air pump is not turning on or not working properly. Bad pump could be a cracked or loose hose as the pumps don't really wear out as it's only air (hopefully clean air, no dust). Call for service.
* The brew cycle might not be completing thus not continuing on to the next step which is to pump air in. Brew sensor or timer out. call for service
* Computer is out or fried (especially after an electrical storm). Call for service.
* Finally, most of these home units do not have serviceable parts. Most take at least an hour to service. So if your not in the warranty period it may not be worth fixing. But be sure to call your service provider or MFR for advice.
Aloha! ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

It sounds like the T-Barbed fitting on top just before the brew head. There is a water by-pass system on large commercial brewers. The idea is that it's possible to over-extract the ground coffee if too much water is poured into the worn out ground. There are several types of systems and ideas on how to overcome this problem. over extraction is one of the causes of bitter coffee. You've tasted old peculated coffee from old brewers of the 1950-60's.
* the t-barb fitting comes from the main brew head valve then tees off to the bypass port which can have another solenoid or just a pin valve. the pin valve is manually adjusted to flow anytime the brew head valve is turned on. water is partially diverted to by-pass the grounds and drips directly along the inside of the brew funnel. Open it too much and you get weak watery coffee. Too little then stronger bitter coffee. I suggest turning it all the way clockwise (off) then opening it 3-1/2 turns. Check and adjust to taste.
* you should call your vendor for service and parts if needed.
* Parts are available from Bunn vendors,, Amazon, or your local restaurant supply as Bunn is a very common brand. Curtis parts may fit too. The barb is a standard 3/8th T fitting if I remember right. You may also find it at a Refrigeration plumbing supply like COSCO plumbing (Not the COSTCO membership store)
* It's just a divert-er so even a nylon t-fitting may work.
* Final; you can find the parts and manuals from Bunn.com even some of the discontinued models.
Aloha! ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

VPS are pour over brewers. Like the 12 cup brewers you find at home, they need to be filled with 12 cups of water (a full pot), heated and then peculated over the coffee grounds and collected in a decanter.
BUT there is one main difference! The VPR and similar COMMERCIAL coffee machines are quick brewers. They usually have a pre-heated pot of water stored inside the machine.
* VPR's and similar machines REQUIRE a pre-fill and heating period prior to brewing. This means it's sitting on a level table and filled with water until water sprays from the brew head. At this point the unit is plugged in and the heater is turned on (CWTF's have a toggle switch behind the machine). Brewer will pre-heat the water (there may be some water discharge from brew head as the water expands). Ready light will come on in about 15 mins.
* To Brew; Place coffee grounds in filter, place in funnel and brew head, clean empty decanter under funnel, slowly pour one full decanter of water (cold or hot) into brew tray. Do not overflow tray. Allow water level to sink before adding more water. Only fill with one pot as an equal amount will come out the brew head and funnel.
* FYI Coffee grounds are usually in pre-messured packets for office use. A simple guide is one tablespoon per cup. (level or heaping spoon is up to you)
* Since your brewer was bubbling at one point. I'm guessing it had water in the pre-heater at one time. But if it's not in use and left plugged in all that time then the water has probably boiled off. Hopefully someone unplugged the brewer prior to the unit blowing the thermal fuse.
* You can test the VPR by following the Pre-fill instructions I've listed earlier. If the brewer heats up and does not continuously boil (shorted condition) then try a brew. If it works then your okay. Otherwise the unit will need service for a blown high limit or bad heater element.
* Call your coffee vendor anyway. Many coffee vendors will service your brewer of even replace it as long as you buy coffee from them. Ask around.

Aloha, ukeboy57

Bunn Coffee... | Answered on Jan 18, 2018

Bunn machine smells hot
* Check for unusual sounds from brewer (other than sizzling from warmer plates). There should be a gradual boiling sound accompanied by some steaming at the top of brewer. This will turn off and ready light indicating the brewer is ready to brew.
* You may sometimes hear a slight boiling sound from time to time (about 15-30 mins apart). Notify your vendor as the warmer blanket may be out. (your brewer will still work but call them anyway.)
* Check your manual for setting up procedures and checks. It's available on line: http://www.bunn.com/product-manuals
* Constant boiling (more than 15 mins) with lots of steaming is a sign of an electrical problem. Unplug machine and call vendor for service.
* Final; Unplug unit and check for 'stuff' in pour over tray. I've found Chocolate, Cream, Milk, powder, sugar, honey, and a dead rat in the tray. Crew will repour old coffee or beverages into brewer to 're-heat' them. Notify vendor for cleaning or replacement (it happens all the time.)
Aloha, ukeboy57

Bunn Coffee... | Answered on Jan 17, 2018

1.check the setting of your timer
2. open the top and see if the pan is overflowing or water is sprayed from the jet .

Bunn Coffee... | Answered on Jan 03, 2018

Hello, Trent -

I checked the User Manual for the Bunn Speed Brew
< http://www.bunn.com/sites/default/files/care-and-cleaning/49740.0001.pdf >
and didn't find the problem you describe in the troubleshooting (Let's Solve) section.

Therefore, I recommend you telephone Bunn Customer Service and talk with a someone there. See this web page to find the right number to call and the days and hours of availability:

The company may need to send you a replacement machine.

Bunn Coffee... | Answered on Dec 24, 2017

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