Water gets warm but not hot

Possible causes may include:
Is the temperature turned up high enough?
Raise temperature on topside control. Follow directions in owner’s manual
Is the spa cover on?
The cover will keep heat in the spa and help keep heat from escaping.
Make sure cover is on at all times when spa is not in use.
See owner’s manual for cover  info.
Is the heater element coated with scale?
If scale has deposited on the heater element the heat will not transfer to the
water properly.
If this is the case, the element or heater will have to be replaced.
Is the heater element old and / or deteriorated?
If the element is subjected to chemical abuse, it will loose its ability to generate
The 240 volt 5.5 kW elements should test at least 10.5 ohms to heat properly.
If they test lower than this, replace the element or XL Heat Exchanger.
Is the filtration time adequate with the spa in economy mode?
If spa is in Economy mode, spa only heats during filter cycle, increase the
filtration time or set • the spa to “standard mode” (see your spa owner’s manual)
Does the temperature reset when the power goes off?
The automatic default for temperature is 100°F even when its set higher.
If power goes off then comes back on, the spa will reset to factory default
temperature of 100°F.

Water Does not Heat at all

Possible causes may include:
Does the spa have enough water?
Check water level. Not enough water in spa will keep heater • from operating.
Fill spa to proper level and make sure pump is primed.
Is the incoming voltage correct?
Check for Incorrect voltage. On 240 Volt or 230 Volt spas, • there needs to be
correct voltage (±10%).
Contact qualified electrician to provide proper electrical supply. See “240 volt
wiring diagram” for further information.
Is the filtration time sufficient to allow for heating of spa?
Filtration times or mode of operation is incorrect. See owners manual for proper
Reset filtration times or operational mode to allow for time to heat spa.
Are any error codes displayed on topside?
Follow the appropriate error message chart
“FL” means the pressure switch is defective. This will shut down the heater.
When was the filter cleaned or changed?
Dirty or clogged filter will restrict water flow and shut down heater.
Clean or replace filter to re-establish water flow.

Water is Too Hot

Possible causes may include:
What is the temperature set at?
If someone raised the temperature on the topside panel, the spa will stay at the
new temperature.
Turn set temperature down to desired temperature. Follow owner’s manual for
additional  information.
What is the filtration time set at?
If the filtration time is set too long, the equipment area gets hot.
During warm months, running the filter cycle for extended lengths of time can
cause overheating where heat transfers to the water from the equipment area
heating up.
Turn the filtration cycles down during the warm months.
Is there adequate cabinet ventilation?
Heat buildup from equipment needs to be vented, if there are obstructions to the
ventilation • or not enough venting, this can also cause overheating.
Make sure the cabinet ventilation is unobstructed. If there is debris, remove it
and make sure the air flow around the cabinet is open.
How long have the pumps been running?
If the high speed pumps run too long, they generate heat from the motor and
the friction of the impeller churning the water.
Given enough time, friction from the pump can overheat water.
During warm months, limit pump cycles to 1 or 2 (15 minutes to 30 minutes) to
help avoid water and equipment overheating.

Spa water is cooler than the temperature displayed on the topside

Possible causes can include:
The water temperature sensor is probably reading heat in the equipment area
instead of the actual water temperature.
This will give the controls false information and cause the heater to shut off due
to the false information.
Add extra insulation on the temperature sensor which force the sensor to read
the water temperature accurately and the controls will react accordingly
Issues Covered in this Section:
  • Water gets Warm but not Hot
  • Water Does not Heat at all
  • Water is Too Hot
  • Spa water is Cooler than the temp
    displayed on the Topside
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Cal Spas®,
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Technicians and is general information on the Repair and
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