Aquah Tankless Water Heater Troubleshooting
On this page (6 sections)
The Short Answer: Most Aquah heaters are small units: portable propane models for outdoor showers and camping, and compact electric models for a sink or two. When one won’t heat, the cause is usually too little water flow to switch it on, dead ignition batteries, an empty or frozen propane supply, or an electric unit without full power. Portable propane units without a vent connection must only be used outdoors.
Which kind of Aquah do you have?
Check the label on the side or back of the unit:
- Portable propane (LP) tankless: a small box with a propane hose connection, a battery compartment for ignition, and no vent pipe. These are outdoor appliances.
- Electric tankless: wired to a 120-volt or 240-volt circuit, often under a sink or on a wall, with a kilowatt (kW) rating on the label.
If your heater has a vent pipe and is installed indoors, it is a different type of appliance; follow its manual and have it serviced by a gas technician.
Portable propane units: what usually goes wrong
| What happens | Likely cause | What to try |
|---|---|---|
| No click, no flame when water runs | Water flow too low, or dead or reversed batteries | Open the tap fully; fit fresh batteries the right way round |
| Clicks but does not light | No gas reaching the burner: cylinder empty or valve closed, regulator frozen, kinked hose | Check the cylinder and hose; try a full cylinder |
| Lights, then goes out | Low flow, wind, low gas pressure in cold weather, or an overheat safety | Increase flow; shelter from wind; let it cool |
| Water too hot or steaming | Flow too low for the gas setting | Turn the gas setting down or open the tap more |
| Water only warm | Flow too high, or very cold inlet water | Reduce flow or raise the gas setting |
| Error code on the display | Varies by model | Check the manual for your model |
Portable units start only when enough water flows through them to trip the flow switch. Garden hoses with low pressure, a kinked hose, or a shower head with a flow restrictor can keep the burner from starting. Many have a small screen at the water inlet that collects grit; if your manual describes cleaning it, do that with the gas off and the unit cool.
Cold weather causes two separate problems: propane cylinders lose pressure as they get colder, and water left inside the unit can freeze and crack it. Drain the unit as your manual describes before freezing nights.
Error codes
We could not find an Aquah code list we could verify against the manufacturer’s documents, and similar-looking portable heaters from other sellers use different meanings for the same codes. Use the manual that came with your unit, or contact Aquah support with the model number. If a code relates to ignition or flame and repeats after checking gas, batteries and flow, stop using the unit.
Electric units: power, flow and size
An electric Aquah needs its full rated voltage and a breaker sized for it. If the display or indicator is dark, check the breaker panel and reset a tripped breaker once. If it trips again, leave it off and call an electrician; see tankless water heater keeps tripping the breaker.
Size matters more with electric units. Each kilowatt can raise roughly 6.8 gallons per minute of water by 1°F, so a 3.5 kW sink heater raises only about half a gallon per minute by 50°F. That is fine for hand washing and far too little for a shower. If an electric unit heats well at a trickle but runs cool at full flow, it is working at its limit. More on this in electric tankless goes cold after a few minutes.
What a technician will check
For electric units, an electrician confirms the supply voltage, breaker and wire size, and the condition of connections. For propane units, a technician can check the regulator and gas pressure, the igniter and flame sensor, and the water flow switch. Low-cost portable heaters often are not worth repairing beyond batteries, hoses, regulators and cleaning; a cracked heat exchanger or failed control board usually means replacement. Similar portable units are covered in Camplux troubleshooting.
Frequently Asked Questions
Q: Can I use my Aquah portable heater in a camper or shower tent? A: No. Unvented propane heaters release combustion gases, including carbon monoxide, where they run. Use them only outdoors in open air, positioned as the manual describes.
Q: Why does my portable unit work in summer but not in winter? A: Colder inlet water needs more heat, and a cold propane cylinder delivers less pressure. Reduce flow, keep the cylinder out of the wind, and use a larger cylinder if your manual allows.
Manuals and supporting references
These links distinguish general safety information from model-specific documentation. A manual directory helps you locate your unit’s instructions; it does not establish that every model uses the same parts, codes, or test values.
- CPSC: carbon monoxide fact sheet (opens in a new tab)Carbon monoxide hazards and emergency response.
- PG&E: recognizing and responding to a gas leak (opens in a new tab)Emergency actions for suspected fuel-gas leaks.
- Bosch: electric water heater troubleshooting FAQ (opens in a new tab)Flow and heating-capacity behavior of the Bosch models listed there. Other models use their own limits.
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