The H2S is the H2D’s platform with one hotend instead of two, and that single change ripples through its whole calibration picture. There is no second nozzle to reconcile, so the H2D’s signature step, nozzle offset calibration between two hotends, does not really apply here. What is left is closer to a large-format A1 mini or P1P: bed leveling, flow calibration, and vibration compensation, run on a 340 x 320 mm bed inside a 65°C heated chamber. The sensors doing the work are not identical to the H2D’s either, and it is worth being precise about which is which, because Bambu’s own documentation uses overlapping terms for genuinely different hardware.
How bed leveling actually works
Z homing and leveling on the H2S rely on two separate sensor systems, not one.
The first is a set of three force sensors mounted under the heatbed itself. Bambu’s HMS fault codes for the H2S group these under 0300-0A00 through 0300-0C00, with separate codes for low sensitivity, high sensitivity, and an external bump or disturbance on the plate. These are the sensors behind Auto Bed Leveling, the routine that checks the nozzle-to-bed gap at multiple points across the plate and compensates for an uneven heatbed or ordinary assembly tolerance.
The second is what Bambu’s H2S documentation calls the "extrusion force sensor," reported through the 0300-1800 code family (signal too low, too high, or abnormal). This name is easy to misread as a third, unrelated sensor. It is not. Bambu’s own H2S maintenance guide for replacing this part calls it the eddy current coil, mounted on the extruder just above the hotend heatsink, with an installation tolerance of 0.15 to 0.5 mm between the coil and the heatsink. In other words, the H2S carries the same eddy-current sensing technology as the H2D, just one coil instead of two, since there is only one hotend to track. The "force sensor" language in the error-code text and the "eddy current sensor" language in the maintenance manual describe the same physical part.
So the H2S’s leveling and Z-homing behavior draws on two different sensor families that happen to share overlapping vocabulary: heatbed-mounted force sensors doing corner-and-mesh probing, and a toolhead-mounted eddy current coil doing contact detection and extrusion-force sensing near the nozzle. A heatbed accelerometer (HMS code 0300-1B00) is a third, separate sensor that watches for a loose or damaged connection rather than participating in the leveling calculation itself.
As on the H2D, there are three passes available from the touchscreen under Settings > Calibration > Print Calibration: Auto Bed Leveling for routine use, High-Temperature Bed Leveling for ABS, ASA, PC, and PA-family filaments (run once the bed hits 80°C or above, using more measurement points for a more accurate plane), and manual bed tramming as a fallback if auto-leveling itself fails. Manual tramming on the H2S is a screw-by-screw process: loosen the fixing screws under and around the heatbed, run a leveling G-code from a USB drive that walks the toolhead through all four corners over three rounds, adjust each corner with a leveling feeler until you feel consistent resistance, then retighten. Bambu is explicit that this is a maintenance step for shipping damage or heatbed service, not something to run routinely, since the H2S ships leveled from the factory.
Vibration compensation and motion accuracy
Two more entries live in the same Print Calibration menu: Vibration Compensation and Motion Accuracy Calibration. Vibration Compensation adjusts toolhead position in real time when the printer detects vibration during printing, which is what keeps fine detail clean at higher speeds. Motion Accuracy Calibration is a separate routine aimed at absolute positioning error, useful mainly on large prints where small amounts of motion hysteresis or belt distortion become visible over a longer travel distance, which matters more on the H2S’s bigger bed than on a compact printer.
There is a dedicated fault family for X-axis resonance (0300-1000-0002-0001 and 0002), and the documented fix for the second of those codes is to clean the axis guideway and recalibrate. That phrasing is Bambu’s way of saying vibration compensation data can go stale if the rails pick up debris, not that the calibration routine itself is broken.
Flow calibration: eddy current, not lidar
The X1 Carbon calibrates dynamic flow by printing lines on the plate and scanning them with a Micro Lidar. The A1 mini and H2D do it differently: they purge filament at the wiper and use the toolhead’s eddy current sensor to read extrusion force during that purge, then calculate a K value from the result. Given that the H2S carries the same single eddy current coil architecture described above, its flow calibration almost certainly follows the A1/H2D purge-based method rather than the X1’s lidar-scan method, though Bambu has not spelled this out in an H2S-specific document the way it has for the other two machines.
Here is where it gets genuinely uncertain rather than just unconfirmed: the H2S’s own HMS index lists offline, dirty-lens, and calibration-chart-failure codes for something Bambu calls "Micro Lidar and toolhead camera" (the 0C00-0100 family), grouped as a single module. So the hardware is present. What it actually does on a single-nozzle machine, whether it participates in flow calibration the way it does on the X1, or is used only for reading the calibration sticker on the heatbed that Bambu’s own component guide describes as calibrating the toolhead camera, is not something the wiki states outright. Treat "H2S uses lidar for flow calibration" as unconfirmed, and "H2S has lidar-related hardware in the toolhead" as confirmed.
Separately, the touchscreen calibration menu still lists Nozzle Offset Calibration, the same entry the H2D uses to reconcile its two hotends. On a single-nozzle machine that reconciliation problem does not exist, so this is most likely a carryover from the shared H2-platform firmware UI rather than a step you are expected to run routinely.
Chamber heat and calibration timing
None of the above is measured at a fixed temperature, and the H2S’s chamber heater (a PTC element and circulation fan, rated to 65°C) changes the frame’s physical dimensions slightly once it has been running a while. That is the reason High-Temperature Bed Leveling exists as its own stored dataset instead of being folded into the standard pass. If a print is giving inconsistent first layers despite a clean leveling result, letting the heatbed and chamber sit at target temperature for ten to fifteen minutes before judging the first layer is more reliable than trusting a reading taken cold.
Common failure signs
A few patterns show up repeatedly in the H2S’s own fault codes:
Plate seating problems. Warped plate, debris, or a plate not fully clicked onto the magnetic bed shows up as build-plate faults (0300-0D00-0001-0003 through 000A) and as a missed build-plate alignment marker read by the chamber camera (0C00-0300-0002-000C).
Nozzle residue. Leftover filament on the nozzle tip throws off both the eddy current reading and the camera-based first-layer check, and is explicitly called out as a cause of abnormal heatbed homing.
Z-axis obstruction. Foreign material on the lead screws or timing pulleys produces its own fault family, distinct from a software leveling failure, and needs physical cleaning rather than recalibration.
Vibration or resonance. X-axis resonance codes point to a dirty guideway rather than a bad calibration run.
When to re-run calibration manually
Run Auto Bed Leveling after any heatbed or build plate swap, after the printer has been moved or shipped, or after any mechanical repair near the bed or Z-axis. Run flow calibration after a nozzle swap (manufacturing tolerances vary between nozzles), after switching to an uncalibrated filament, or after changing max volumetric speed or print temperature in a filament profile. Add High-Temperature Bed Leveling before your first print with ABS, ASA, PC, or PA-family filament, or after the printer has been sitting idle since its last one. A nozzle swap that fails to register correctly (the printer reports it can’t detect the hot end) is usually a seating problem with the heating assembly, not a calibration problem, and is worth checking before you assume a sensor has failed.
Related H2S guides
This is part three of a five-part Bambu Lab H2S setup series: Unboxing and Safe First Setup, First Print Walkthrough, Loading, Unloading and Changing Filament, and Bambu Studio Setup. For the dual-nozzle version of this same calibration architecture, see the Bambu Lab H2D calibration guide. If the printer throws a fault code, see the H2S Error Code Index.