Hot tub overheating or showing OH?
An OH / OHH shutdown means the spa sensed water too hot and cut power. The usual causes are low flow from a weak or failing pump, a bad temperature sensor, a stuck heater relay, or scale in the heater tube trapping heat.
from $149 · $69 diagnostic credited to your repair
The spa shut itself down to protect you
OH, OHH, OHS and HOT are all overheat faults. The control board watches the water temperature, and the moment a sensor reports it has climbed past a safe ceiling — typically around 108–112°F — it cuts the heater and often the pumps, then displays the code. Like a flow fault, this is a safety response: the spa is telling you it saw a temperature it won't allow.
The most common real cause isn't that your tub is genuinely too hot to enjoy — it's low flow. When a weak or failing circulation pump moves water too slowly across the element, the thin sheet of water touching the heater superheats locally even though the tub as a whole is fine. The sensor reads that hot spot and shuts down. Scale narrowing the heater tube does the same thing, choking flow right where it matters most.
The other suspects sit in the control side. A failing temperature sensor can simply read high when the water isn't, tripping a false overheat. And a stuck heater relay that won't release keeps the element energized past the set-point, genuinely cooking the water until the cutout fires. Sorting a flow problem from a sensor or relay fault is what the diagnostic settles.
We'll confirm which for $69 — credited to the repair
A few clues lean one way; we verify it on site before any work.
Likely low flow / pump if…
- The circ pump is quiet, intermittent or warm
- You've also seen FLO or HL codes
- Flow feels weak even with a clean filter
- Heat-up runs hot then trips, over and over
Likely a sensor or relay if…
- Flow seems perfectly normal but OH still trips
- The water doesn't actually feel scalding when it faults
- The reading on the panel jumps around oddly
- The heater seems to stay on past the set-point
Find the false reading or the real heat, then fix it
Diagnose
We verify actual water temperature, measure flow across the heater, and test the sensor and relay against spec.
Flat quote
Once we know whether it's flow, a sensor or a relay, you get the published price up front — diagnostic credited.
Repair
We restore flow with a pump or descale, replace a drifting sensor, or fit a relay so the heater releases properly.
Verify
We confirm the tub reaches its set-point and holds it without tripping OH before we leave.
Most overheat repairs are completed same-day across Palm Beach County.
Don't just keep resetting an OH fault
Repeatedly clearing an overheat code without fixing the cause lets the heater keep running with poor flow — which scales the element faster and stresses the board. If the OH returns within a session or two, leave it off and let a tech find whether it's flow, a sensor or a stuck relay. Master Spas owners take note: an OHH on those is often calcium scale in the heater tube.
Flat-rate, published up front
Price depends on whether it's a flow switch, the circ pump, or a heater assembly — confirmed at your $69 diagnostic.
Not quite your symptom?
Sensor error (Sn1 / Sn3)
A temperature or hi-limit sensor reading out of range.
PumpFLO flow error
The flow switch can't confirm water past the heater.
PumpCirc pump replacement
A weak circ pump causing low flow and overheat trips.
HeaterNot getting hot enough
Scale or weak flow capping the water temperature.
Answers before you call
They're overheat codes. A sensor reported the water climbing past a safe limit, so the board cut the heater to protect you. It usually points to low flow superheating the element locally, a faulty sensor, a stuck relay, or scale in the heater tube.
Often the whole tub isn't overheated; the thin layer of water touching the element is, because flow across it is too low. A drifting temperature sensor can also report a false high reading. Both are confirmed at the diagnostic.
Don't override it repeatedly. If the cause is a stuck relay the water can genuinely overheat, and running on poor flow scales the element faster. Leave it off and have the flow, sensor and relay checked.
From $149 for a flow/pressure switch, up to a circulation pump or a complete heater assembly. You get the flat price before we begin.
Same-day across most of Palm Beach County, with a real arrival window rather than a vague all-day wait.
We'll find why it's overheating — today.
Flat-rate from $149. Same-day. $69 diagnostic credited to your repair.
Tell us when it trips — we'll call back within the hour
No call center. Just a local, licensed tech who'll check flow, sensor and relay and quote the price before any work.
Quote request sent
We'll call you back within the hour. Hot tub out cold right now? Call us at (561) 555-0143.