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Kiln Controller Guide: KilnMaster vs Bartlett Genesis

How the Skutt KilnMaster and L&L Bartlett Genesis controllers work: cone-fire versus ramp-hold, 1-zone versus 3-zone firing, and which features matter.

By The Kiln Shed Team · Updated June 18, 2026
Interior of a ceramics studio at the Leach Pottery showing kilns and equipment
The controller is the interface between the potter's firing schedule and the kiln's actual behavior. Cone-fire mode handles the schedule automatically; ramp-hold mode lets the potter program every segment. Both Skutt's KilnMaster and L&L's Bartlett Genesis offer both modes. geishaboy500, CC BY 2.0 via Flickr

The kiln controller is the electronic system that manages the firing schedule. It reads temperature from thermocouples inside the kiln, compares that reading to the programmed schedule, and switches kiln elements on and off to follow the schedule’s ramp rates and holds. All electric kilns reviewed on this site include a digital controller as standard equipment.

Two controller systems appear across the kilns reviewed here: Skutt’s KilnMaster (on KM-series kilns) and L&L’s Bartlett Genesis (on the e23T). The fundamental difference is zone count: the KilnMaster is a 1-zone controller, the Bartlett Genesis is a 3-zone controller.

KilnMaster (Skutt)

The KilnMaster controller ships on all Skutt KM-series kilns including the KM-1027, KM-1018, and KM-818. It is a 1-zone digital controller: one type-K thermocouple positioned inside the kiln wall provides the temperature reading, and all kiln elements cycle on and off together based on that single reading.

Cone-fire mode: Select the target cone and firing speed. The KilnMaster runs its built-in schedule for that cone at the selected speed (slow, medium, or fast). Three speeds correspond to three different programmed ramp rates; slow schedules protect thick or damp ware, fast schedules complete in fewer hours. The controller fires through all segments and holds automatically without further input.

Ramp-hold mode: Manually program up to 8 firing segments. Each segment specifies a ramp rate (°F/hr or °C/hr), a target temperature, and an optional hold time at that temperature. After the final segment, the kiln holds at temperature (if a hold is programmed) and then begins cooling by natural convection when elements cycle off. Ramp-hold mode is used for custom schedules outside the standard cone-fire parameters.

Features:

  • Delay start: program the kiln to begin firing at a future time
  • Preheat: optional slow low-temperature hold to drive off remaining moisture before main schedule begins
  • Skip segment: advance to the next segment mid-firing
  • Hold: extend the current hold time while firing
  • Review: display current temperature and segment status during firing
  • Error codes: thermocouple failure, element fault, and temperature overshoot alerts
Small ceramic teapot and ceramic vessels representing the output of a controlled kiln firing
The controller's job is to fire the kiln to a repeatable standard. Whether a production run of mugs or a glaze test batch, the programmed schedule should produce the same result in every firing. The KilnMaster's cone-fire mode is the starting point; ramp-hold mode is where experienced potters tune schedules for specific results. (Photo: orcmid, CC BY 2.0 via Flickr)

Bartlett Genesis (L&L e23T)

The Bartlett Genesis is manufactured by Bartlett Instrument Company for L&L kilns. The e23T includes it as standard equipment. The Genesis is a 3-zone controller: three separate thermocouples positioned at the top, middle, and bottom sections of the kiln provide independent readings, and three independent relay circuits control the top, middle, and bottom element groups separately.

Each zone fires at its own rate to maintain equal temperatures across all three sections simultaneously. If the top zone reads cooler than the middle and bottom (a common condition as heat rises and the lid area loses heat), the Genesis drives the top elements harder to compensate. If the bottom runs hot, the bottom relay reduces cycling. The result is more even temperature distribution from top to bottom than a 1-zone system can produce.

Cone-fire mode: Same concept as the KilnMaster: select cone and speed. The Genesis programs the schedule and manages all three zones through the firing automatically.

Ramp-hold mode: The Genesis supports a larger number of programmable segments than the KilnMaster, with the same segment structure (rate, target, hold). The 3-zone management happens behind the scenes regardless of whether cone-fire or ramp-hold mode is used.

Features:

  • Independent thermocouple readings for top, middle, and bottom
  • Diagnostic mode: test individual elements and thermocouples
  • Zone-by-zone temperature display during firing
  • Delay start, preheat, skip, hold, and review functions similar to KilnMaster
  • Error codes for thermocouple failure, element fault, zone overshoot, and zone lag
Collection of finished glazed pottery pieces after a kiln firing cycle
Consistent firing requires consistent temperature across the kiln load. A 3-zone controller addresses the fundamental problem that the top section of a tall kiln behaves differently from the bottom during any firing. Work at the top and bottom of the load should come out at the same degree of cone maturation. (Photo: Robert Collins, Unsplash License)

1-zone vs. 3-zone: does it matter for home studios?

For most home studio potters, a KilnMaster 1-zone controller produces satisfactory results. The KM-1027 and KM-1018 are well-designed kilns with element placement that reduces top-to-bottom variation; many potters run these kilns for years without detectable consistency problems related to zone count.

The 3-zone advantage becomes more apparent in specific situations:

  • Tall, fully loaded kilns: the taller the kiln relative to its diameter, the more pronounced the top-to-bottom temperature gradient. The e23T’s tall proportions (greater interior height than many comparable kilns) make the 3-zone system particularly useful.
  • Work that is sensitive to even slight temperature differences: certain glaze effects, tightly tolerated porcelain firings, or matching color samples rely on consistent temperature throughout the load.
  • Production potters loading to maximum density: a 1-zone controller fires to the thermocouple’s location; work above and below that location may reach slightly different temperatures. This variance is small in typical studio conditions but cumulative in repeated firings.

For a home studio potter firing 25 to 50 times per year on standard stoneware with commercial cone-6 glazes, either controller produces reliable results. The 3-zone system is an upgrade; it is not a necessity for most home studio applications.

A digital kiln controller panel with keypad and temperature display
The controller is the part you actually operate: a digital keypad like this runs the ramp-and-hold schedule the elements follow. darkday via Flickr. CC BY 2.0.

Thermocouple maintenance

Both controllers use type-K thermocouples, a bimetallic junction that generates a small voltage proportional to temperature, which the controller converts to a temperature reading. Thermocouples drift over time as the junction ages from repeated thermal cycling. A thermocouple that reads 2232°F while the actual kiln temperature is lower or higher will produce inconsistent results that look like schedule problems.

Typical thermocouple service life: 300 to 500 firings for a type-K thermocouple in cone-6 use; shorter life at cone 10. Annual witness cone verification catches drift before it affects production. Replacement thermocouples are available from Skutt and L&L dealers and are an inexpensive service item.

Potter loading ceramic ware into a top-loading electric kiln for firing
Loading strategy affects how evenly a 1-zone kiln fires. Experienced potters place the most thermally sensitive work at mid-height near the thermocouple and use denser loads at the top and bottom to compensate for edge-of-stack temperature variation. A 3-zone controller reduces (but does not eliminate) the need for strategic loading. (Photo: Kampus Production, Pexels License)

Which controller for which kiln

The controller in each kiln is determined at purchase; both are included as standard and not independently selectable across models:

  • Skutt KM-1027: KilnMaster (1-zone)
  • Skutt KM-1018: KilnMaster (1-zone)
  • Skutt KM-818: Skutt FireBox (a simplified version of the KilnMaster with core cone-fire and ramp-hold functions)
  • L&L e23T: Bartlett Genesis (3-zone)
  • Paragon Caldera: Paragon Sentry 2.0 (1-zone, designed for the small-kiln format)

The Bartlett Genesis’s 3-zone architecture is part of the technical case for the L&L e23T in the Skutt vs L&L comparison. For firing schedule structure that works with both controllers, see the kiln firing schedules guide. For individual model reviews, see the KM-1027 review and L&L e23T review.

Frequently asked questions

What is the difference between the Skutt KilnMaster and the L&L Bartlett Genesis controller?

The KilnMaster is a 1-zone controller: one thermocouple reads temperature in one location and controls all kiln elements together. The Bartlett Genesis on the L&L e23T is a 3-zone controller: three independent thermocouples (top, middle, bottom) control separate element sections independently. The 3-zone system produces more even firing from top to bottom of the kiln. Both controllers offer cone-fire and ramp-hold programming modes.

What is cone-fire mode on a kiln controller?

Cone-fire mode is a simplified programming option where the potter selects the target cone number (for example, cone 04 for bisque or cone 6 for glaze) and a firing speed (slow, medium, or fast). The controller runs a built-in schedule designed for that cone and speed, handling all ramp rates and hold times automatically. Cone-fire mode is appropriate for potters learning a new kiln or running standard schedules, and produces consistent results without manual schedule programming.

What is ramp-hold mode?

Ramp-hold mode (also called manual mode) allows the potter to program each segment of the firing individually: the ramp rate in degrees per hour, the target temperature for that segment, and any hold time at that temperature. The KilnMaster supports up to 8 segments; the Bartlett Genesis supports more. Ramp-hold mode gives complete control over every variable in the firing and is used by experienced potters who need precise schedules for specific clay bodies, glaze chemistries, or special effects.

Does the L&L e23T come with the Bartlett Genesis controller?

Yes. The L&L e23T includes the Bartlett Genesis 3-zone digital controller as standard equipment. The Bartlett Genesis is manufactured by Bartlett Instrument Company specifically for L&L kilns. It controls the three kiln sections (top, middle, bottom) through independent relays driven by three separate thermocouples.

Can a 1-zone controller produce uneven firing from top to bottom?

Yes, and this is the primary argument for 3-zone control. In a 1-zone kiln, the single thermocouple is typically positioned in the middle of the kiln. The top section of the kiln loses heat through the lid opening and wiring; the bottom section may run hotter or cooler depending on element loading and airflow. A 3-zone controller adjusts each section independently to reach the same temperature simultaneously, producing more even results across the full kiln height.