Hot tub not heating? Common causes and what to do
Nothing kills the relaxation vibe faster than lifting your hot tub cover and realizing the water is still cold. If your hot tub isn’t heating properly (or at all), the issue can range from a quick fix to a part that needs professional repair. Let’s break down the most common causes and what you should do next.
Dirty or clogged filter
Clogged filters are one of the most common heating problems. When water cannot flow properly, the heaters switch off to prevent damages.
If you believe you have a dirty or clogged filter, remove it from the hot tub and rinse it thoroughly. If you believe it may be greasy or scaled, try soaking it in a filter cleaner which can easily be found online.
If your filter is over a year old, it is always best to replace it so you know your hot tub is being filtered correctly.
Low water level
Hot tubs need adequate water flow to heat safely and their sensors will soon know if the water level has dropped. If the water level drops below the skimmer or jets, the heater may not engage.
If you believe it may be an issue with the water level, check the water is covering all jets and refill as needed. If you have refilled the hot tub at all, restart the system and see if the heaters then kick in after a while.
Low water is easy to overlook but surprisingly common.
Tripped breaker or power issue
Sometimes the hot tub’s heater may not be the issue and it could be because it is not getting any power.
If you believe it may be a power issue, check the GFCI breaker and reset it once. Do not reset this multiple times as this may cause more damage. If the tub turns back on, look for any error lights or codes which may then diagnose the issue.
If the breaker keeps tripping, call a professional. This could either indicate a heater issue or an electrical failure.
Faulty heater element
Heating elements wear out over time, especially in older hot tubs or tubs with poor water chemistry.
Here are a few signs that the heater element is faulty.
Water temperature stays the same
Hot tub runs normally otherwise but without being heated
No visible error codes
Unfortunately, you will need to contact an engineer to resolve this problem as it is not a DIY-friendly repair. An engineer will be able to test the element and replace it safely.
Circulation pump problems
If the water isn’t moving around your hot tub, heat will not be able to distribute or turn on at all.
Common issues which can suggest circulation pump problems can include weak or no water flow, unusual noises or the heater failing shortly after being switched on.
If you believe this is a problem with your hot tub, check for any air locks and make sure the valves are fully open.
If the above options have been completed, it may be time to call an engineer to diagnose the problem.
Thermostat or control board issues
Your hot tub may think the water is already hot or it cannot communicate with the heater. Therefore, it won’t heat. Signs this is what is happening to your hot tub may include incorrect temperature readings, the heater not engaging at all or random system behavior.
This issue usually requires expert diagnostics.
When to call a professional
You should contact a hot tub engineer if the breaker keeps tripping, the tub shows error codes you can’t clear, the water isn’t heating after basic troubleshooting or you suspect heater, pump, or electrical problems.
Trying to force a fix can lead to bigger and more expensive repairs.
If you would like to book a callout to diagnose and fix any hot tub issues, contact us directly through our website or call us on 01604 312773.