Bunn Coffee Maker Troubleshooting Guide (Speed Brew, Velocity, Phase Brew)

Start With Which Bunn You Own

Most Bunn problems come down to three things: the tank switch, the 15-minute warm-up, and lime in the sprayhead. But BUNN sells four quite different home brewers, and the fix depends on which one is on your counter. A Speed Brew or Velocity Brew keeps a tank hot all day. A Phase Brew or Heat N Brew heats each pot from cold. A My Café brews single cups through slide-in drawers.

This page is the index. Each problem below gets the short answer from BUNN's own manuals and a link to the full guide.

---

Try This First

• Find the right switch. On glass-carafe Speed Brew and Velocity Brew models, the front warmer switch only heats the plate. The tank is on the side or back switch.
• Give it 15 minutes. That's how long BUNN says the tank takes to reach temperature after switch-on or a brew.
• Close the lid fully. Water doesn't leave the pour-in bowl until it does.
• Pour at least 20 oz. It's the smallest batch a Speed Brew or Velocity Brew makes.
• Clean the sprayhead if it's been more than 3 months.

---

Won't Turn On

No BUNN home manual describes a reset button or a fuse you can reach. On the always-hot models, check the outlet, then the tank switch (side on a Speed Brew; the vacation switch on a Velocity Brew, showing red when on). A Phase Brew or Heat N Brew starts with its On/Off or Brew button, and the red light should come on. Full steps: Bunn won't turn on.

---

Cold or Lukewarm Coffee

A hot warming plate with cold coffee nearly always means the warmer switch is on and the tank switch is off. The Velocity Brew manual says outright that the warmer switch "is NOT the vacation switch". After that, wait the full 15 minutes, and if the temperature has dropped over months, delime the tank. Full steps: Bunn not heating. Phase Brew and Heat N Brew owners: Phase Brew not heating.

---

Won't Brew

On a Speed Brew or Velocity Brew, nothing moves until the lid is closed and at least 20 oz is in. After storage or a move, the tank needs refilling through BUNN's Initial Setup, with power last. Water left standing in the pour-in bowl means a clogged sprayhead. Full steps, including the Phase Brew, Heat N Brew and My Café: Bunn won't brew.

---

Brewing Slowly

BUNN names two causes: clogged sprayhead holes, and lime in the tank and sprayhead tube. Clean the sprayhead, then run the deliming tool through the tube and the quart-of-vinegar clean. A healthy Speed Brew or Velocity Brew takes 3 to 4 minutes, while a Heat N Brew takes about 10 by design. Full steps: Bunn slow brewing.

---

Funnel Overflowing

BUNN lists three causes: non-BUNN filters, a missing sprayhead, and coffee that drains too slowly (decaf, fine grinds or soft water), for which it sells a flow restrictor sprayhead. Measure to the chart, too: 10-11 tablespoons for a 50 oz pot. Full steps: Bunn overflowing.

---

Leaking

Where the water appears matters. Water escaping before the lid is closed is the pour-in bowl's rubber stopper. Water under the base has one answer in the Speed Brew manual: call BUNN, and never disassemble the coffeemaker. On a My Café, a leak around the sprayhead is the sprayhead or its seal. Full steps: Bunn leaking.

---

Rumbling and Other Noises

A rumble after brewing, and now and then through the day, is the tank reheating, and BUNN calls it normal. Rumbling that never settles points to lime on the heater, so run the vinegar clean. A My Café that's suddenly loud, or whose pump keeps running, has scale on its water probes. Full steps: coffee maker making loud noise.

---

Codes and Lights

There are only a few.

A Phase Brew flashes CLE for a deep clean. A Heat N Brew shows CLEAN, cleared by holding H and M for 3 seconds after cleaning, and EE:03 when it detects no water. A My Café uses red and green lights. Speed Brew and Velocity Brew have no display at all. Full table: Bunn error codes and lights.

---

Off Taste

The My Café manual answers "off taste" with its brewer cleaning (14 oz of vinegar, then three or more water cycles) and one habit: take used coffee or tea out of the drawer after every brew. The Heat N Brew has its own "off taste" row, so check your manual for its wording. On any Bunn, a vinegar smell after cleaning means the rinse cycles weren't finished. Full steps: Bunn descaling guide.

---

Cleaning and the Sprayhead

Every home Bunn wants a vinegar clean about every 3 months.

That's 1 quart on a Speed Brew or Velocity Brew, 10 oz with 30 oz of water on a Phase Brew, 25 oz with 25 oz of water on a Heat N Brew, and 14 oz on a My Café. Vinegar is the only cleaning liquid BUNN allows in the tank. The sprayhead comes off by hand after a 2-hour cool-down (1 hour on a My Café, where it turns clockwise to remove). Full steps: Bunn descaling and Bunn spray head cleaning.

---

When to Call BUNN

Stop using the brewer if:

• Water is pooling under the base
• There's a burning smell, or the breaker trips
• The cord or plug is damaged
• A My Café sprayhead seal is cracked or torn

Support: 1-800-352-2866 (USA), 1-800-263-2256 (Canada), or retail.bunn.com/support/products. Have the model and date code ready: they're etched on the power cord's metal prongs, or printed on the bottom or lower back.

Warranty: three years from purchase on a new Speed Brew, Velocity Brew, Phase Brew or Heat N Brew, glass carafe excluded. Two years on a My Café MCU. Every warranty excludes damage from "use with water having a high mineral content", so regular cleaning protects the warranty as well as the machine.

Repair or replace: BUNN publishes no parts list for its home brewers, and every manual says there are no user-serviceable parts inside. The parts an owner can get from BUNN are the deliming tool, a flow restrictor sprayhead and, for the My Café, a sprayhead seal. Anything inside the housing is a warranty claim or a service call.

---

Bunn Care Schedule

---

FAQ

Should I leave my Bunn switched on?

For a Speed Brew or Velocity Brew, yes. BUNN designs them to stay plugged in with the tank switch on, and the Velocity Brew manual calls daily use of the vacation switch unnecessary. Switch off only for setup, cleaning, or a break of several days.

Is there a reset button on a Bunn?

No. None of BUNN's home manuals shows one on the Speed Brew, Velocity Brew, Phase Brew, Heat N Brew or My Café. The only button combination is the Heat N Brew's H + M hold, which clears its CLEAN indicator.

Does a Bunn work at high altitude?

Standard Speed Brew models aren't designed for use above 4,000 feet, and BUNN sells high-altitude units. For the Phase Brew, it's the models with a "D" designation. The My Café has a high-altitude setting: press Pulse five times within 10 seconds.

What temperature does a Bunn brew at?

BUNN doesn't publish one for the Speed Brew or Velocity Brew. The Heat N Brew heats water to 200 °F (93 °C), and the My Café holds its tank at about 200 °F. Any other figure you see for the always-hot models isn't from BUNN.

How long does a Bunn warranty last?

Three years on a new Speed Brew, Velocity Brew, Phase Brew or Heat N Brew (glass carafe excluded), and two years on a My Café MCU. Repaired or replacement brewers received after the original warranty, and remanufactured brewers, get one year.

---

Related Bunn Guides

• Bunn Coffee Maker Won't Brew?
• Bunn Coffee Maker Not Heating?
• Bunn Coffee Maker Leaking Water?
• Bunn Error Codes and Lights
• How to Descale a Bunn Coffee Maker

Sources: BUNN Speed Brew Owner's Manual (53883.0002, models GRX/BX/SBS/CSB1/CSB2/BTX/CSB3T); BUNN Speed Brew Owner's Manual (53883.0001A, models BT/CSB/GR/SB); BUNN Velocity Brew 10 Cup Use & Care Manual (43097.0002D01, models NHS/GR/BX/BT/ST); BUNN Phase Brew 8 Cup Use & Care Manual (HT/HG); BUNN Heat N Brew Model HB Use & Care Manual (52774.0000a); BUNN My Café Single Cup Multi-Use Brewer Use & Care Manual (MCU, 43460.0002D).