This Weeks Sale This Weeks Specials!
Mon-Sat - 7am-7pm CT

Heater Troubleshooting

Unless it's a hundred degrees outside or you are a Polar Bear, sitting around in cold water is no fun and it's clearly not what you bought your spa for. In fact, a simple thing like a heater gone bad can turn your spa into a giant, ridiculously expensive ice tray. So when you find yourself saying "Holy guacamole that's cold!" instead of "Ahhhh, that's nice..." you know it's time to check your spa heater.

Common Symptom:
  • No hot water

Warning! WARNING: Electricity and water are a dangerous cocktail. DISCONNECT THE POWER AT THE GFCI SWITCH AND/OR THE MAIN PANEL CIRCUT BREAKER or FUSE BEFORE INSPECTING OR INSTALLING SPA PARTS. Do not attempt to install any powered spa part unless you are qualified. If you have even the slightest doubt, call a spa technician or electrician before proceeding.

Spa Heater Assembly
Spa Heater Assembly

Troubleshooting Your Spa Heater

Note: The following relates to electric heaters only. If your heater assembly generally looks like this, please read on. If not, please contact us.

Flo-Thru Heater Element
Flo-Thru Heater Element: enlarge

The "Flo-thru" Heater Element looks like this and it is housed in the Heater Assembly (above):

  1.  1. First, check to be sure your spa has electricity. Check your control panel to see of your spa is on, then check your GFCI (a breaker built into a power outlet or housed in a separate box), your high limit (see photo) and your home circuit breaker or fuse box. If your GFCI is tripped, there's a good chance your heater element is at fault. If your hi-limit switch is tripped (usually located on your heater or control box-see below), it probably means you are not getting water flow and you should check your pump(s) before going forward here. If nothing is tripped and you are still getting no power, it's time to break out the Yellow Pages and call a spa tech or electrician. If you have juice, move on the number 2.

  2.  2. If you have electricity but no hot water...Check to see if the spa is working. If you have a digital "topside" control panel, check to see if there are any error codes displayed; OH and FLO are the most common. OH means your spa is overheated and FLO means there is a problem with the water flow. If you have no water flowing from your jets, the water can't be heated and you should check your spa pump(s). If your water is overheating and it is not extremely hot outside, you may need to replace your thermostat or your Hi-Limit switch. If you hear the pump running but still have no flow, check to be sure your filter isn't dirty and the water level isn't low. If either of these conditions exist, correct the problem. If you have a digital control — turn the power off for 1 min to reset the error code. If you have water flow and the the Heat light is on (digital controls) but you still have no heat, go to #3. Keep in mind that fresh spa water will take hours to heat. 240v spas need 6 to 12 hours, 115v spas can take 12 hours plus.

  3.  3. Locate you heater assembly which is most often a metal tube housing a heating element and some other stuff. The "other stuff" includes a pressure switch (2 common types are circled here), sensor probes and heavy gauge wires.
Locate Your Heater Assembly Locate Your Heater Assembly

  1.  4. Check the terminals and wiring. Look for rust or excessive corrosion on the terminals or discolored wires. If you find any of these, it's usually best to replace your entire heating assembly as replacing only the element may be difficult or impossible.

  2.  5. If there is no rust or corrosion and the wiring looks good (and you are handy), you can try removing and replacing the heater element.
  • First, remove the entire heater body from the control box. There are no short cuts here.
  • Carefully remove the wires from the pressure switch, then unscrew the pressure switch.
  • With the pressure switch out of the way you can usually get at the small mounting nuts (usually 2), one at each end of the heater body — pay attention though, there may be more than two.
Remove the 1/4 nuts from the wire terminals
Remove the 1/4 nuts from
the wire terminals

  • Remove the 5/16" nuts from the element's wire terminals, be careful here — you may need to use a smaller wrench to hold the small area just below the terminals (this will help keep the entire unit from twisting off). This step is very important when reinstalling the element as well.
  • You may have a sensor cover. If you do, remove the small nut and pop the cover off. These covers can be stuck in place so don't be afraid to give it a tug.
  • Loosen the threaded end collars and are at each end of the heater. The entire unit should now be loose and ready to be removed. In some cases, there may be some additional wires that need to be removed so be sure to look for them.
Remove the large nuts
Remove the large nuts

  • Once the unit is out of the spa, remove the large nuts that hold the heater element in place.
Remove the large nuts
Push down on the terminals

  • Once the nuts are removed, push down on the terminals. They should drop low enough to pull the element out the end of the housing.

Remove the large nuts
Avoid bent terminals

  1.  6. IMPORTANT NOTE: In this picture, the terminals are bent over. Avoid this when installing the new element. If you damage the terminals or the epoxy that surrounds the terminals, the warranty will be voided.

  1.      After you receive your new heater element, you can re-install your heater assembly. To re-install, reverse the steps above. Take it slowly and be cautious. If your new element comes with washers, they will go on the outside of the assembly body. O-rings go inside the body. DON'T lube or use any silicone on these seals. Tighten the large nuts to approximately 20 foot pounds or snug but DO NOT OVER TIGHTEN.

Click here to select a new heater assemblyClick here to select a new heater element
Sign up to receive exclusive email news & offers!
Sign up to receive exclusive email news & offers!
Submit Email Address
MC VISA AMEX Discover PayPal Ask the Spa Tech
HACKER SAFE certified sites prevent over 99.9% of hacker crime.