Finding the correct replacement heater is one of the most important steps in repairing a hot tub or spa control system. Many spa heaters look similar, but differences in wattage, length, plumbing size, sensors, pressure switches, electrical connections, and control-system compatibility can make one heater correct and another completely wrong.
If you have a Balboa Water Group heater, the best place to begin is usually the identification label attached to the heater assembly.
Once you locate the heater part number, use our Heater Finder to determine whether the original heater is still available, has been replaced by a newer part number, or requires another compatible solution.
Where Is the Balboa Heater Part Number?
On many Balboa spa heaters, the manufacturer's identification label is attached directly to the metal heater tube or heater assembly inside the spa equipment compartment.
The label may contain several different numbers, so knowing which one is the actual heater part number is important.
In the heater-label example above:
- #1 identifies the heater description.
- #2 identifies the heater part-number information.
How to Read a Balboa Heater Label
In this example, the heater label displays the following number:
58083***1005140015
The important number for identifying the heater is the first five digits:
58083
The remaining characters may contain production, manufacturing, date, or other identification information and are not normally the replacement part number you would use to identify the heater.
Once you have the five-digit heater number, enter it into our Heater Finder.
What Does Balboa Heater Part Number 58083 Identify?
Part number 58083 identifies a Balboa M7-style heater assembly used with compatible spa control systems.
More specifically, the 58083 heater is a:
- Balboa Water Group heater
- 5.5 kW heater
- 15-inch heater assembly
- 2-inch plumbing configuration
- M7 sensor-style heater
This is a perfect example of why identifying the part number is preferable to simply looking at the heater tube. Many 15-inch, 2-inch spa heaters look nearly identical but are not necessarily interchangeable.
What If the Original Heater Part Number Has Been Replaced?
Older Balboa heater numbers are often superseded by newer replacement numbers as products are updated.
This means the number printed on your original heater may no longer be the number shown on the current replacement.
That does not necessarily mean the heater is unavailable.
Our Heater Finder includes known replacement relationships for many older and discontinued heaters so you can begin with the number printed on the original part.
Don't assume you need to find the exact same number printed on the original heater. Enter the original number into our Heater Finder. A current replacement or superseding part number may already exist.
What If the Heater Label Is Missing or Unreadable?
Unfortunately, heater labels do not always survive as long as the heater itself.
After years inside a hot equipment compartment, a label may become:
- Faded
- Discolored
- Cracked
- Water damaged
- Partially detached
- Completely missing
The label may also simply be difficult to see because of the position of pumps, plumbing, or other equipment inside the spa cabinet.
If you cannot read the heater part number, the heater can often still be identified using other information.
Use the Spa Control System to Identify the Heater
The heater is part of the complete spa control system, so the control-system model or part number can often help determine which heater was originally used.
Look for a label on the spa control box. Depending on the system, it may include:
- Balboa system part number
- Control-pack model
- System series
- Voltage information
- Heater rating
Our Heater Finder can also help identify heaters using spa control-system information.
Know Whether You Have an M7 Heater or a Pressure-Switch Heater
One of the most important differences among Balboa heaters is how the control system verifies water flow and temperature.
Balboa M7 Heaters
Balboa M7 systems use two sensors installed in the heater assembly. The control system compares the sensor readings to monitor temperature and help determine whether adequate water movement is present.
If your heater has two M7 sensors positioned near the ends of the heater tube, that is an important identification clue.
Pressure-Switch Heaters
Older and other Balboa systems may use a pressure switch instead of the M7 sensor arrangement to help verify water flow.
A pressure-switch heater should not automatically be replaced with an M7 heater—or vice versa—simply because the physical tube appears similar.
Check the Heater Kilowatt Rating
Balboa has manufactured spa heaters in several power ratings.
Two of the most common are:
- 4.0 kW
- 5.5 kW
The correct wattage depends on the control system and electrical configuration.
Do not assume that installing a higher-kilowatt heater will make the spa heat faster or provide an upgrade. The circuit board, wiring, relays, breaker, and electrical system must all be designed for the heater being used.
Measure the Heater Length
Heater length is another important identification point.
Many Balboa flow-through spa heaters use a heater tube approximately 15 inches long, but Balboa and other manufacturers have produced different lengths for different control systems.
Measure the heater assembly rather than relying on memory or assuming all Balboa heaters are the same size.
Check the Plumbing Size
Many common Balboa spa heater assemblies use 2-inch plumbing connections, but plumbing size should still be verified.
The heater must properly match the existing unions and circulation plumbing.
Do not confuse the nominal plumbing size with the outside diameter of the threaded union or fitting.
Check the Electrical Connection
Balboa heater electrical connections have changed across different generations of spa control systems.
Depending on the system, the heater may use:
- Direct terminal connections
- Plug-style electrical connections
- Balboa Plug-n-Click connections
- Other control-system-specific wiring arrangements
The replacement must be compatible with the existing control system or include the appropriate conversion components.
Check for Mounting Studs, Brackets, and Other Differences
Even heaters with the same basic dimensions can differ in smaller but important details.
Compare:
- Mounting studs
- Sensor locations
- Pressure-switch ports
- Union orientation
- Electrical connection location
- Grounding connection
- Control-box mounting arrangement
These details can determine whether the replacement installs correctly in the existing equipment area.
Don't Identify a Heater by Appearance Alone
This is one of the most common mistakes made when replacing spa heaters.
A stainless-steel 15-inch flow-through heater tube with 2-inch plumbing can look almost identical to several other heater assemblies.
The correct identification should be based on as many of the following as possible:
- Manufacturer part number
- Known replacement part number
- Control-system model
- Kilowatt rating
- Voltage
- Heater length
- Plumbing size
- Sensor configuration
- Pressure-switch configuration
- Electrical connection
- Mounting arrangement
What If My Original Balboa Heater Is Discontinued?
Many older Balboa heater assemblies have been discontinued over the years.
A discontinued heater does not necessarily mean the entire spa is obsolete.
Depending on the original heater, there may be:
- A direct current replacement
- A superseding Balboa part number
- A compatible replacement heater
- A replacement requiring an updated electrical connector
- A heater that is no longer available but can be addressed through a control-system retrofit
The best first step is to enter the original heater number into our Heater Finder.
When Does a Complete Spa Control System Replacement Make More Sense?
In some cases, the heater is only one aging component in an older spa control system.
If the original heater has been discontinued and the control board, topside panel, sensors, or other system components are also becoming difficult to replace, a complete spa control-system retrofit may be a more practical long-term solution.
A retrofit can replace several aging components at once with a current system that has better future parts availability.
That decision should be based on the condition of the complete spa system rather than simply the price of the heater.
Have the heater part number? Use our Heater Finder to search it.
Can't read the heater label? The Heater Finder can also help you identify the heater using spa control-system information and other identifying details.
Before Ordering a Replacement Spa Heater
Before ordering, compare the replacement against the original heater and verify:
- Part number
- Known replacement relationship
- Kilowatt rating
- Voltage
- Heater length
- Plumbing size
- M7 sensors or pressure-switch configuration
- Electrical connector style
- Mounting configuration
- Control-system compatibility
A few minutes spent confirming these details can prevent ordering a heater that looks correct but cannot be used with your spa.
Need Help Identifying Your Balboa Spa Heater?
Start with our Heater Finder.
If you still cannot identify the correct replacement, give Bath & Spa Parts Online a call at 800-918-9143.
When contacting us, try to have:
- The heater part number, if available
- The spa control-system model or part number
- Heater wattage
- Heater dimensions
- Clear photos of the heater
- Photos of the heater label
- Photos of the sensor or pressure-switch configuration
- Photos of the electrical connections
That information can make identifying even an older or discontinued heater much easier.