Mueller Ultra Kettle M99S 1.8L Electric Kettle

Boil speed, energy and the wattage conflict

Measured performance is the strongest part of the record. Shouldit, working to a published methodology, took 1.5 L of 80°F water to a rolling boil in 7 min 14 s and used 148 Wh to do it. Their power meter read 113 V, 10.97 A and 1230 W. Wirecutter, testing the same SpeedBoil kettle, found it boiled as quickly as the kettle it recommends. Food Network, having tested more than 12 kettles, picked this one as its value choice and described it as no-frills but effective. Energy is modest too: at a typical US electricity rate of about $0.15/kWh, a 1.5 L boil costs roughly 2.2 cents.

Buy on the measured figure, not the nameplate. The M99S instruction manual cover is marked 110-120V 50/60Hz 900-1100W, while Mueller Living’s own product page and every retail listing say 1500W. No source explains the gap — it may be a manual shared across models or a labeling error — so plan for roughly 1230 W of draw and leave the rest of the circuit alone.

Heat retention, handle and lid

Glass is why the kettle looks the way it does, and it is also why the water cools. Shouldit recorded 203°F (95.5°C) five minutes after switch-off from 212°F, and attributed that to glass carafes holding heat less well than stainless. If you brew several rounds in a sitting, count on warming the water back up.

The rest of the handling notes come from the same test. The handle curve sits closer to the carafe than average and was judged inconvenient for larger hands. The lid is plastic inside and out, has no silicone sealing band, and gave off no odor on the first boil. Owners add that the lid is not removable, which makes thorough internal cleaning awkward, and that the lid-release button can get hot after boiling. The cord does not wrap tightly either, leaving roughly 3.74 in including the plug protruding.

What owners report

Owners consistently praise the speed, the blue LED, the clear glass and how clean it looks on a counter, and a few report long service: one used a Mueller kettle daily for over five years before the lid hinge failed, and another used an M99S daily since August 2019. The caution is early failure. The dominant pattern is the on/off switch or thermostat giving out, or the kettle shutting off before a full boil; a compilation of recent verified owner reviews lists units stopping after roughly 4 months, 8 months, a year, 16 months and 18 months, with several owners suspecting the power switch or reporting shorting out. One owner reported a ring of crackled glass at the base with pieces falling out, and another a loose screw rattling inside the base after less than three months. Lid and hinge issues recur, and hard-water owners see limescale within days to weeks. No source publishes a failure rate, so treat these as signals, not a defect rate. A single r/fixit thread about a Mueller kettle that kept shutting off never names the model, so it is a brand-level report rather than an M99S claim.

Repairs, upkeep and running costs

Upkeep is light: clean the interior and the removable mesh filter, and the manual covers cleaning, descaling, troubleshooting and warranty. The manual recommends descaling once a month in hard-water areas and seasonally for frequent use; there are no consumables, no filters and no subscription, so the only running cost is electricity plus descaler if you use one.

Parts are the weak point. No carafe, base, element, switch or thermostat for the M99S is listed by Mueller or by any parts supplier, and the box holds no spares, so a failed base means replacing the kettle. Warranty is 1-year limited per the packaged manual and the listing copy; one aggregator advertises 24 months, which no Mueller page confirms, and the Mueller Home warranty page defers the term to the sales platform, so check the term you are actually sold at checkout. Owners who failed inside the warranty period report that Mueller replaced units in some cases.

Is it worth it?

It depends where the number lands. Mueller Living’s own store lists the Ultra Glass Kettle at $44.99, Walmart showed $44.99 for the 1.8 L M99S and $42.00 for the 1.5 L variant on the same page, CostLess Wholesale listed it at $29.97, and two smaller sellers had it at $23.75 and $23.50. Food Network’s roundup quoted $36 against a $40 regular price, $45 at another retailer and $80 at Wayfair.

Below about $30 it is a defensible buy for a kettle whose only job is boiling, especially since there is no parts channel to pay into. In the $40-50 band the flimsy base and the missing parts channel start to show, and Wirecutter found a visually similar Cosori kettle with a similar boil time range, a simple on/off switch and much the same design, which is the comparison to make at that money. Above $50 there is no case for a single-temperature kettle with no service channel when a steel kettle with a water-level window or one with variable temperature costs similar. The store panel above carries the live figures.

Which model this is

This page covers the Mueller Living / Mueller Austria M99S, a 1.8 L borosilicate carafe on a cordless base, sold under several names: Ultra Kettle, Ultra Glass Kettle and Premium 1500W SpeedBoil. It also carries the internal code MLR0020, and several UPCs circulate for what looks like the same hardware. Published dimensions disagree by roughly an inch in each direction and by 0.6 lb, so treat them as unverified.

Keep it separate from the 1.5 L Mueller Living glass kettle, from the separate Mueller RapidBoil 1.8 L listing, and from stainless-bodied Mueller kettles; “Mueller” also covers unrelated plumbing, gas and electrical-component businesses, so match on M99S or MLR0020 when you compare listings. The US listing is ASIN B07TZ5YHJN.

Sources

Manufacturer:

• MuellerLiving Ultra Glass Kettle product page
• Kettles — Mueller Living collection

Manual:

• Mueller Austria M99S electric kettle instruction manual (Manuals+)
• Mueller Living Electric Kettle user manual for M99S / MLR0020 (Manuals+)

Independent reviews:

• Mueller Ultra M99S Electric Kettle review — Shouldit
• Shouldit kettle reviews, hands-on tests and buyer’s guide
• Wirecutter: The Best Electric Kettle
• Food Network: electric kettles tested and reviewed
• Video review of the M99S boil time (YouTube)

Retail listings:

• Mueller Ultra Kettle M99S at Walmart
• Mueller Ultra Kettle M99S at CostLess Wholesale
• Mueller Ultra Electric Kettle at Target

Owner reports:

• Mueller Ultra Kettle M99S owner comments (WaterZen)
• A Mueller kettle that kept shutting off (r/fixit)