The stove must never be lit unless the water level is at least 2" above the weld connecting the chimney collar to the stove body. Firing the stove with inadequate water can cause physical damage to the firebox, chimney and firebox fence, and poses a real safety hazard. This can't happen if the water level is sufficient, so please follow the manual instructions carefully and ensure everyone with access to your tub does the same before every fire, especially after refilling or draining. Newer models are built with a fill-line marking and a QR code on the firebox lid — whereas older tubs must note the 2" measurement directly rather than relying on a visual marker. With proper water level maintained, the firebox is built to last 15+ years.

Welding can be attempted, but replacement is the more reliable fix. Pinhole leaks are usually caused by firing the firebox with insufficient water, or by rainwater mixing with ashes inside it. Prevent this by keeping the storage cover on whenever the tub won't be used for an extended stretch.

Likely condensation, or a chimney cap that isn't intact or properly seated — check that first.

This can happen with certain wood types or from incomplete combustion. A professional chimney sweep can clear it; no special precautions are needed beyond protecting the aluminum from abrasive tools.

Check that the black collar is fully tightened and that the O-ring is present and seated correctly. If the collar itself is cracked or broken rather than just loose, see the replacement heater connection collar above.

That's the pump cord. It plugs into the control/heater box at the blue, rubberized, watertight connector — reconnect it there and you're all set.

Ensure the four black ring gaskets are installed at the end of each hose connection and threaded connections are secured with teflon tape.

If a power outage occurs and there's a power surge when power returns, it can blow a fuse in your system. If your system stops working after an outage, check the fuses inside the control panel with the power off — look for a fuse that's turned black, shows a burn mark, or has a broken wire inside it. If you find one, a fuse replacement will get the system operational again.

Email hi@alumitubs.com for a replacement:

• F3 heater fuse — part #24514 for a 240V heater, or part #26982 for 120V.
• F4 and F5 board protection fuses — part #26983.

This typically points to a fault at the heater connection or moisture getting into the electrical components — not an issue with your home's wiring, especially if the tub is on its own dedicated breaker. Don't run additional heating cycles unattended until it's been looked at — email hi@alumitubs.com for support.

If you're seeing this pattern — the system powers on and starts priming normally, the pump runs and the heater engages, but after a few seconds to a minute circulation stops and the heater shuts off, the system re-enters a purge cycle or shows a flow/heater error, the displayed temperature jumps by a few degrees without the water actually changing temperature, and/or the jets start and stop inconsistently — and you've already confirmed the water level, both black equipment valves are open, bled the filter canister, tried a new filter, and power-cycled at the breaker, this usually points to a relay in the control board rather than trapped air. Reach out to hi@alumitubs.com — a replacement board is a straightforward swap.

First bleed the air out of the filter canister with the power off. To do so, open the air release knob on the filter canister until water flows out steadily, then close it and power the unit back on. If the short-cycling continues after that, it likely points to the control board and is worth a support email to hi@alumitubs.com.

This triggers if wood heat pushes the water temperature above 108°F on a Hybrid unit. This is inside the control box, so you'll need to flip down the cover (see the diagram in the manual for the dip switch location). While the power is on, move dip switch 1 to the ON position. Wait one minute and see if the error code clears. If it clears, turn the power off to the system, turn dip switch 1 off, then power the system back on — everything should be back to normal.

Email hi@alumitubs.com — we'll send a replacement touchpad.

If the touchpad is working and displaying normally but the water isn't heating, this can point to the heating coil (heater element, tube, and sensors) rather than the control board. Email hi@alumitubs.com with your address — we'll get a replacement heating coil assembly sent out.

Download the ControlMySpa app (iOS or Android), open Setup, confirm Bluetooth is on, and stand within about 10 feet of your tub with it powered on. The app will detect your WiFi module via Bluetooth — confirm the serial number shown matches the one printed on the back of the module, then enter your CMS code (provided with your tub) to finish setup. The app will only be able to connect to the tub in the first 10 minutes that it's powered on.

First, double-check that the serial number on the WiFi module matches what's shown in the app during setup — a mismatch is the most common cause. Also check that IPv6 is disabled on your home WiFi network, as this can prevent the module from connecting. You can also read the module's status light for a quick diagnosis:

• Solid red — not connected to the tub's system at all.
• Blinking red — connected to your home network, but not talking to the tub's control board.
• Blinking green — connected to the tub, but no internet connection (check your home router).
• Solid green — everything's working.

If the serial numbers don't match, or the light suggests the module itself isn't communicating, email hi@alumitubs.com for a replacement.

The ballast has its own status light. Solid green means it's powered and running normally — this should always be lit whenever the system has power. Solid red means the UV-C lamp itself is actively on. If you're not seeing green at all, it's a power or connection issue rather than a bulb problem.

Clean the quartz tube every 6 months.

In over 26 years of building AlumiTubs, we've found leaks trace back to one of three things: the tub froze with water left inside, the base isn't fully level and supported, or the firebox was lit without enough water in it (or the tub was drained while the firebox was still hot). All three are covered in your manual, and all three are fixable once identified.

• Froze with water inside: ice expanding inside the tub can pop the aluminum rivets holding the structure together, which shows up as a leak at a seam. See your manual's freeze prevention guidance for your system type.
• Base isn't level or fully supported: see below for the fix.
• Firebox lit with insufficient water, or drained while still hot: see Firebox Issues above.

Not sure which applies? Send a few photos or a short video of where it's leaking to hi@alumitubs.com and we'll help you pin it down.

Marine-grade aluminum can develop surface changes from electrochemical reactions combined with imbalanced water chemistry or hard/soft water extremes — this is cosmetic, not structural.

Before considering a recoat, there are two things worth trying first, since minerals in your fill water (like copper or iron) are a common cause: a hose filter when filling the tub (a PreFresh Hose Filter is a good option), and a descaling product like Spa Scale Defender, since minerals are sometimes left behind in filters and crevices even after a fresh fill — a descaler can help clear the source.

• Tubs built after June 2026 have a protective coating rated to 350°F and are safe with all approved treatment methods.
• For tubs built before June 2026: restore the surface by removing deposits with a plastic spatula or lightly sanding to bare aluminum. Contact hi@alumitubs.com for support with water chemistry, electrochemical balancing, and information on applying a protective coating to prevent recurrence.

This applies to seam sealant. Clean the area with lacquer thinner or acetone, remove the old sealant with a putty knife, and reapply SikaFlex. Note: this seam sealant is a separate product from the clear coating on the aluminum interior — use the right process for the right surface (see below).

This is likely due to the tub not being fully supported, causing a hairline crack in the sealant. Resolve this by fully supporting the tub, then reapplying a heavy bead of sealant 1ft in each direction of the leak, pressing and smoothing it with a gloved finger, and letting it cure for 24 hours.

Check the drain kit connection first and reseal at the base outlet if needed — most post-move leaks trace back to the drain fitting needing to be re-threaded after the tub was dismantled and rebuilt on a new platform.

This is a different process from seam sealant, above:

1. Clean the area — wash with a high-volume hose and mild pH-neutral soap, or Nyalic Right Rinse. Don't use a pressure washer, shop air, or solvent cleaners, as these can damage the coating. Let it dry completely.
2. Inspect for chips, scratches, or rust beneath the clear coat.
3. Spray a thin layer of Nyalic aerosol over the damaged area — it self-levels and blends with the existing coating.
4. Let it air-dry fully. Avoid moisture or temperatures below 55°F (12.8°C) for at least 48 hours, and don't return the tub to service for 2 weeks to allow a full cure.

Use Thompson's Water Seal (clear wood sealer) — this is best applied before installation so all sides of the cedar can be coated evenly.