Balboa error codes
Updated October 2026
Balboa control systems are fitted to many makes of hot tub. Here’s what the messages on a Balboa panel mean, what you can safely check yourself, and which ones need an engineer.
Type your Balboa code into the troubleshooter for the safe checks.
Look up a codeWhat Balboa codes mean
| Code | What it means | What to do |
|---|---|---|
| HFL | Heater flow is reduced. The heater stops, then tries again after about a minute. | Do the flow checks below. |
| LF | Heater flow is still reduced after repeated HFL messages, so the heater is switched off. | Do the flow checks, then press any button to reset. |
| dr | The heater may be dry, or there isn’t enough water in it to start. The tub shuts down for 15 minutes. | Do the flow checks. Press any button to reset. |
| dry, dY | The heater is dry. After three dr messages in a row, the tub shuts down. | Do the flow checks, then press any button. If it comes back, call us. |
| OHH | Heater too hot. A sensor in the heater has read 47.8°C (118°F), so the tub shuts down. | Don’t get in. Reset with any button once the water is below 42.2°C. It’s usually a flow problem. |
| OHS | Water too hot. The water has reached 43.3°C (110°F), so the tub stops. | Don’t get in. Take the cover off. It resets itself below 42.2°C (108°F). |
| SnA, Snb, SnS | A temperature sensor fault: sensor A or B has failed, or the two sensors disagree. | This needs an engineer. |
| COOL | The water is 11°C (20°F) or more below the set temperature, usually after a refill. | No action. It heats back up. |
| ICE | Freeze protection. The pumps and blower run to stop the water freezing. | No action. It isn’t a fault. |
| Pr | Priming mode, for about four minutes after the power comes on. The heater stays off. | Run each pump to clear the air, then press a temperature button. |
| -- | Water temperature unknown, until the pump has run for about a minute. | Wait. If it doesn’t change, call us. |
Codes vary between Balboa systems and panels, so if your display shows something else, check your manual or our error code guide.
The flow checks Balboa recommends
Balboa’s own checklist for HFL, LF, dr, dry and OHH is the same every time. Switch off at the isolator before you take the filters out.
- Top up the water if it’s low.
- Take the filters out, clean them and refit them.
- Open any closed valves, and open the jets: too many closed jets cut the flow.
- Clear any blockage around the suction fittings.
- Clear trapped air: after a refill, run each pump during priming mode until water flows from the jets.
Don’t let a pump run without water flowing for more than two minutes. Balboa warns it can damage the pump and overheat the heater. If it won’t prime after a few tries, switch off and call us.
Words, icons and M-codes
Newer Balboa panels show messages as words or icons, and save each fault in a fault log with a message code, so an engineer can see what happened and when.
| Message code | What it means |
|---|---|
| M016, M017 | Heater flow reduced (HFL, LF) |
| M027, M028 | Heater dry, or may be dry (dry, dr) |
| M029 | Water too hot (OHS) |
| M030 | Heater too hot (OHH) |
| M031, M032 | Sensor A or sensor B has failed |
| M015, M026 | Sensor balance is poor: the two sensors disagree |
| M033 | Safety trip: suction blockage (not every tub has this) |
| M034, M035 | A pump appears to be stuck on |
If the panel says a pump is stuck on (M034 or M035), switch off at the isolator and don’t get in. Balboa warns the water may overheat.
Control faults sorted
From 47 reviews on Google
“Jon installed a new control panel and overlay to my Marquis Hot Tub excellent job and even managed a modification that the manufacturer had not allowed for. Any future problems and he will be the first person I call.
Nigel Lace, Penryn Cornwall”
“Jon an absolute legend, very friendly, came out diagnosed the issue went away ordered the part came back fixed it tested it fixed another problem that came up after testing again and all for a very reasonable price. Will use him again and again 🌟
Paul from porth / newquay”
“Jon was very helpful and friendly, diagnosed and fixed the problem there and then.”
Balboa code still showing?
Switch off at the isolator, then ring or WhatsApp us with the code and a photo of the panel.
If your tub is sunk into decking or the ground, or set against a wall, it helps to mention it when you book. If you’re not sure, a photo is fine.
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