The hot tub heater is a cylinder that contains a heater element inside and a metal sheath or manifold on the outside. Two posts encased in epoxy on the top of the heater tube bring the necessary power from the circuit board to the heater. Heaters also have either internal or external sensors that sense temperature and overheat conditions. Older style spas have an external pressure switch that is sometimes mounted to the heater tube. Newer style heaters such as the Balboa M7 type have the sensors mounted inside the heater, eliminating the need for an external pressure switch.
Heater failure can manifest itself as a tripping GFCI breaker or that the spa does not heat despite power being applied from the circuit board to the heater terminals.
Caution, the heater terminals have full voltage and can cause shock, so it is recommended to only allow qualified persons to work on a spa and also that the power is off and the breakers also turned off.
Heater Repair Tips
When removing the heater from the plumbing, do not remove the screws that may be on the heater union. It is also a good idea to replace the heater gaskets when closing the heater tube back up.
Spa electrical and heaters should only be worked on by qualified persons as working on any appliance can be very dangerous and lead to electrical shock or other injuries. This article provided for information purposes only and is not intended to be a comprehensive how to guide. Call a qualified tech if you need assistance in repairing your spa. Qualified techs may use this information as a primer on some things that can go wrong with hot tub heaters.
When accessing the heater, the power pack door is opened by removing the top 2 screws on newer Balboa packs.
One of the number one causes of a tripping GFCI or hot tub heater failure is that a drop of water may find its way onto the heater post between the insulator and post causing a short circuit.
If removing the heater strap from the heater, hold the part with a wrench to avoid breaking the heater post.
To isolate the heater from the pack, the power of the heater is removed. If the breaker resets, then the problem is with the heater and it may need to be replaced.
Some may decide to try to replace just the heater element, but the epoxy that holds the heater post in place as well as the actual placement of the heater element makes this an exercise not recommended. It is best to replace the entire heater.
Another issue is the 0.3 amp system fuse on the circuit board which could render the entire spa in a non-operating state. Nothing will work including the topside control panel if the 0.3 amp fuse has blown. Whenever work is being done on the power pack, be sure the electricity is off/disconnected and breakers are off.
For assistance on getting a new replacement heater or other spa parts, contact Hot Tub Outpost USA.