Troubleshooting

This page is deliberately not a repair guide. A hyperbaric chamber is a pressure vessel and, in most configurations, an oxygen-enriched environment, and the failure modes that matter are the ones where an owner's improvisation makes things worse. What follows is a triage framework: how to describe a symptom accurately, which symptoms mean stop immediately, and what information a service technician needs so the first visit is the only visit.

Symptoms that mean stop now

These are not "monitor and see" items. Stop the session, decompress according to the manufacturer's procedure, and do not use the chamber again until a qualified person has examined it.

• Any sign of heat, burning smell, smoke or discolouration. FDA has published reports of fires with HBOT devices resulting in serious injuries and deaths, with root cause not known (FDA, 25 August 2025).
• Visible damage to an acrylic window — crazing, cracks, scratches, cloudiness, or impact marks. ASME PVHO-2 makes the user responsible for the window's safe service life and defines formal inspection levels including a Maintenance Visual Inspection by a qualified inspector (ASME PVHO-2-2019 preview pages). A window is not a cosmetic component.
• A relief valve that has lifted, or that you suspect has lifted. Published settings give you the reference point — the Sechrist H-series publishes two relief valves at 35.00 psi on the 3300H and 36.00 psi on the 3600H and 4100H (specifications).
• Emergency vent or decompression control that does not respond as documented. The Sechrist H-series publishes an emergency vent from 30 psig to 0 in a maximum of 119 seconds (specifications) — if your chamber does not behave as its own specification describes, that is a stop.
• Occupant distress of any kind, including ear pain. Middle-ear barotrauma is documented at meaningful rates in supervised clinical settings — 262 cases among 2,610 patients in a five-year analysis (PMID 32574438), and 68.7% of 67 users in an earlier report (PMID 8470522), with onset especially during compression (review of middle ear barotrauma after HBOT).
• Any electrical fault — tripped breaker, hot plug or cable, burning smell from the compressor or concentrator. FDA recommends ensuring the device is properly grounded (FDA, 25 August 2025), and electrostatic sparks are a documented ignition mechanism in hyperbaric oxygen (PMID 4163554).

Symptoms to log and report, not to fix

Slow pressurisation, or failure to reach set pressure

Record the target pressure, the pressure actually reached, the time taken, the room temperature, and whether the behaviour is new or has been degrading. Do not adjust relief valves and do not restrict a purge or vent path to hold pressure — a purge flow is a safety function, published as 80–400 lpm at 15 psi for the Sechrist H-series (specifications), and an oxygen accumulation caused by inadequate ventilation increases chamber fire risk (chamber ventilation study).

Suspected leak

Note where, whether it is audible, whether it varies with pressure, and whether it started after a specific event such as a move or a cleaning. On fabric chambers, zips, seams and gasketed penetrations are the usual locations; the clearance description characterises these chambers as urethane-coated nylon inflated by a small electric pump (K072757). Do not apply sealants, tapes or adhesives that are not specified by the manufacturer — an unapproved material introduced into an enriched atmosphere is an unassessed flammability risk, and product flammability increases with oxygen fraction and pressure (PMID 18349735).

Compressor behaviour: cycling, overheating, noise change

Record ambient temperature against the chamber's published operating range — the Sechrist H-series specifies 50–100 °F and 30–90% relative humidity at 77 °F (specifications) — and check whether the machine has adequate clearance and airflow. Also record what else is on the electrical circuit, since the published electrical data for these products is a circuit requirement rather than a load: "Standard 120V / 15 AMP Circuit" (Summit to Sea Grand Dive), "110-120V" for the Fortius 420 compressor (OxyHealth), and no electrical specification at all in the Sechrist brochure. Do not defeat a thermal cut-out.

Concentrator output low, or alarming

Compare against the published specification rather than an impression: the AirSep NewLife Intensity 10 publishes 2–9 L/min at 92% ±3% and 10 L/min at 90% ±3%, with a 20 psig outlet, and an operating temperature range of 41–95 °F (specifications). The literature describes medical concentrators generally producing 90–96% oxygen (PMC8275632). Check that the unit is inside its temperature range and not sitting in the chamber's own heat before concluding the machine has failed.

Occupant reports the oxygen "feels weaker"

Before suspecting the concentrator, check the interface. In a 17-person study, properly fitted masks produced 96–99% end-inspired oxygen at sea level and at 2.4 ATA, while improperly fitted masks ranged from 64% to 100% (PMID 871282). A comparative study of delivery systems found acceptable inspired oxygen fraction reliably achieved with a continuously ventilated hood, or with trained supervision of a demand-valve oral-nasal mask system (PMID 8931286). Fit and interface are the more common variable.

Noise complaints

Establish whether the noise is new or inherent before treating it as a fault. Across 41 hyperbaric centres at 2.4 ATA, in-chamber levels ranged from 40.5 dB(A) without ventilation to 100.4 dB(A) with ventilation running (sound level study across 41 centres). Ventilation is loud by design, and reducing it to reduce noise is trading a safety function for comfort.

How to write a service report a technician can act on

Most avoidable second visits happen because the first report was "it isn't working properly." Send this instead:

• Make, model and serial number; for rigid chambers, the vessel identification and window fabrication date.
• Total sessions and cumulative pressurisation cycles to date — you need this anyway for the ASME PVHO-2 window service-life question (preview pages).
• Exactly what you observed, in numbers: target pressure, achieved pressure, elapsed time, flow settings, alarm codes verbatim.
• Room temperature and relative humidity at the time.
• What changed before the symptom appeared: a move, a clean, a new consumable, a power event, a new appliance on the circuit.
• Whether the symptom is repeatable, and under what conditions.
• Photographs and a short video with sound, particularly for noise and for anything visible on a window.
• Your maintenance history, including last filter change and last relief-valve verification.

What not to do, and why

• Do not adjust relief valves. They are set to published values and are the last defence against overpressure.
• Do not restrict purge or vent paths. Inadequate ventilation allows oxygen accumulation, which increases fire risk (ventilation study).
• Do not substitute non-specified materials — lubricants, sealants, tapes, cleaning products, skin products. Flammability potential rises with oxygen fraction and pressure (PMID 18349735).
• Do not add oxygen to a chamber not cleared for it. FDA states that it "has not cleared these bags for use with oxygen tanks or oxygen concentrators," and describes such configurations as homemade HBOT devices posing risk of fire and suffocation (FDA consumer update, archived; content current 26 July 2021).
• Do not operate outside published environmental limits while waiting for service.
• Do not run unattended sessions to "test" a fault. The two most recent MAUDE death reports under product code CBF both describe flash fires during self-treatment (openFDA MAUDE).

Reporting problems beyond your own service call

Adverse events involving medical devices can be reported to FDA through MedWatch, and the MAUDE database is where those reports become searchable (openFDA MAUDE for product code CBF). It is also worth knowing that regulatory action happens in this category: one recall record lists "The Rejuvenator" with the cause "No Marketing Application" (FDA recall record). Checking whether your model has a recall history is a five-minute task with a real payoff.