Not every "won't cool" job is the same problem. Here's how our techs actually work through it — in order, cheapest and most likely first — plus real jobs we've closed out.
Cheapest and most likely causes first — this is the same sequence our techs run on a service call.
Confirm the chiller is powered and the compressor is audibly running before diagnosing anything else. A tripped breaker or a loose plug looks identical to a "broken" chiller from the outside.
Ice means a refrigerant charge or airflow problem — not something to run through. Unplug it, let it thaw fully (24 hours), and don't chip the ice off. Running it iced up damages the compressor.
A chiller can be 100% healthy and still fail to cool if water isn't moving through it fast enough. Check the filter for clogging and confirm the pump sounds normal before blaming the chiller itself.
If power, ice, and flow all check out and it's still not cooling, you're likely looking at a failing compressor — or, on a retrofit chiller, a unit that was never sized for your tub's water volume.
Anonymized from actual service visits — city, brand, and what our tech actually found on site.
Chiller running but unable to hold temperature. Diagnosis: failed compressor — no amount of flow or airflow troubleshooting was going to fix it. Compressor replacement resolved it.
Pump sounded crunchy, flow rate was low, and the compressor had started icing over. Manufacturer's own team confirmed: unplug, thaw fully 24 hours, then re-diagnose once the ice is gone.
Retrofit standalone chiller, every component tested healthy, still couldn't hold temperature. Working theory: a leak in the system reducing effective cooling capacity — flagged for follow-up pressure test.
Three things cause this most often: a failed or failing compressor, ice buildup on the coils or lines (a refrigerant or airflow problem), or low water flow through the chiller — if water isn't moving fast enough, the chiller can't exchange heat even when every component is healthy. A tech needs to listen to the unit, check for ice, and check your flow rate to tell which one you have.
Yes — stop running it and don't chip the ice off. Ice almost always means a low refrigerant charge or restricted airflow, and running it iced up longer causes real compressor damage. Unplug it, let it thaw fully (usually 24 hours), and have it inspected before running it again.
Yes, and it's one of the most missed causes. A partially clogged filter, a struggling pump, or a kinked line can all cut flow enough that the chiller genuinely can't keep up, even though the compressor itself is fine. We always check flow before assuming it's a chiller problem.
Yes. If a chiller was added to an existing tub rather than sold as a matched system, mismatched capacity for the water volume is a real possibility — the unit runs constantly and still can't hold temperature, especially in a warm climate or an enclosed space with poor airflow around the chiller.
Ice on the unit, a burning smell, a breaker that trips every time you plug it in, or standing water near any electrical connection. Unplug it and call — that's not a DIY situation. Text or call (619) 289-9282.
Every diagnostic visit includes a full inspection, not just the symptom you called about — and a same-day report with photos.