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Caution: Electrical repairs can be dangerous, especially around water. We recommend that repairs be referred to a qualified electrician or spa technician. Regardless of who performs the work, make certain that all electrical power to the hot tub or spa is disconnected prior to making any inspections or repairs. The information  provided here is for educational purposes only.


Spa Parts Catalog
Air Button Hot tub air button control Electromechanical spa equipment systems use air buttons to control components such as spa jet pumps, lights, blower, etc.  The buttons are connected to the control box air switches with flexible air tubing.  This allows switching spa components on and off without electricity at the spa side.
Air Control hot tub air control The air control is simply a valve, located topside,  which controls the amount of air introduced into the hot tub's jetting system.  Turning the knob counter-clockwise increases the air.  Turning clockwise decreases or shuts off the air.
Air Switch spa air switch At the other end of the air button tubing is an air switch. Located in the control box, these switches electrically control various components of hot tubs such as: jet pumps, lights, blowers, etc. 


Repair Parts Catalog
Blower hot tub blower Air blowers are used to pump outside air into the spa water.  These are used less in today's spas because they tend to waste energy by reducing the spa's water temperature.
Hot Tub Parts Catalog
Clock Timer spa control system timer clock Electro-mechanical hot tub control systems use timer clocks to control the run timing of the low speed pump circuit, which operates the spa's heat, filtration, and ozone functions. Multiple on/off cycles can be set per day. Electronic hot tub control systems use solid-state electronics to control these cycles, instead of a timer.
Contactor/Relay spa control system contactor or relay A contactor or relay is a switch that consists of two independent circuits. The lower power circuit controls an electromagnet which in turn operates the contacts, opening and closing the high power circuit (such as the heater or pump). When the control circuit is not energized, the spring pulls the contact armature away, the circuit is not complete, and the device (such as heater) is shut off.
Control System spa control system The control system or box is the brain of a hot tub, consisting of the clock timer (in electromechanical systems) and various switching components, and may also contain the spa's heater.  A complete spa pack equipment system also includes the pump.  Electronic control systems will have a printed circuit board inside, rather than individual replaceable components.
A - Pump suction, B - Pump discharge, C - Heater coupling
Spa Parts Catalog
Diverter Valve spa diverter valve A diverter valve allows zone control of the jet action in hot tubs.  Allows you to divert water from one group of jets to another.  Not all spas are equipped with diverter valves.
Repair Parts Catalog
Filter Canister hot tub spa filter cannister system If the spa's filter cartridge is not housed in the skimmer, it may be a separately housed in a filter canister in the equipment enclosure.  These are available with bottom plumbing (shown) or top plumbing; pressure, suction, or universal types are available.
Filter Cartridge hot tub filter cartridge element The spa filter cartridge element is either housed in a compartment in the spa itself, often with an integral skimmer basket, or may have its own standalone filter canister.
Fuse spa fuse High current fuse of the type typically found in a hot tub control system.  Current ratings range from 10 to 60 amps.
Hot Tub Parts Catalog
GFCI Weather-proof covered outdoor GFCI outlet

GFCI Disconnect with Branch Circuit

A GFCI is an electrical safety device which monitors current flowing from Hot to Neutral.  It trips and breaks the circuit if there is any imbalance, such as might be caused by a bad heater element. It can sense a mismatch as small as 4 or 5 milliamps, and react as quickly as 1/30th of a second. (Outdoor GFCI outlet pictured above).

Our Connecticut Electric GFCI Disconnect Box uses a special high-current GFCI for maximum protection (shown left).

Spa Parts Catalog
Heater Element hot tub heater element The heater element consists of special nichrome wire which creates heat as a result of its resistance to the electricity flowing through it.  It is surrounded by a powdered ceramic, and encapsulated in a very strong metal sheath. Heater elements is spas usually fail due to corrosion from improper water chemistry.  When a small amount of water penetrates the sheath, the resulting short will normally cause the GFCI to trip, shutting down all power to the spa.
Heater Manifold spa heater assembly The heater manifold surrounds the heater element, allowing water to flow through and exchange heat.  It may also house the high limit and pressure switch and has plumbing couplings on either end.
High Limit Switch spa hi-limit switch with reset button The high limit is a safety switch which is normally closed until there is a problem with excessive temperature. Once the temp reaches its set point, it latches open, breaking the circuit. This prevents the heater from meltdown if there is an equipment failure. It must be manually reset by pressing its button, after the temperature condition has returned to normal. A tripped high limit causes power to be cut before the fuse, immediately shutting down both pump and heater.  High limit switches (A) sense temperature with a capillary tube attached to a bulb, which is housed in a thermowell. Type (B) is a surface mount sensor also called a thermodisc.  NOTE: on older systems, the high limit may only cut power to the heater element when tripped.
Repair Parts Catalog
Impeller Spa pump impeller The impeller is located in the wet end of the pump.  It spins with the pump motor, centrifugally pulling water in (suction side) and forcing it out (pump discharge end).
J Hot Tubs Parts Catalog
Jet hot tub jets Jets come in many shapes and sizes. Shown is an adjustable hot tub jet with air and water fittings.
Spas Parts Catalog
Light Assembly spa light with colored lenses The spa light assembly (shown exploded view) consists of colored lens cover, light wall fitting, nut and reflector/bulb-holder. Most spas use 12 volt light circuits.
Light Transformer hot tub 12 volt light transformer The light transformer reduces the voltage down to 12v for operating the spas low voltage safety/mood light.
Repair Parts Catalog
Ozonator spa ozonator The ozonator is a device which produces ozone for spa water purification.  The ozonator is connected electrically to the spa's controller to operate with the low speed pump.  The ozone is introduced into the jet lines using an ozone injector.
Ozone Injector ozone injector or Mazzei
The ozone injector is device which draws ozone into the water flow from the attached ozonator via flexible tubing or bypass manifold, using Venturi action.  Sometimes called a Mazzei injector.
Hot Tubs Parts Catalog
Pressure Switch/
Flow Switch
spa flow switch - pressure switch The pressure switch or flow switch is a safety device which shuts off the heater circuit if water flow is interrupted.  Closed during normal spa operation, it snaps open if pump fails or an air pocket forms.  This prevents the heater from meltdown if there is an equipment failure.
Printed Circuit Board hot tub printed circuit board If your spa's control box has a printed circuit board inside, it is an electronic control system.  This means that the timer and many other functions are solid state, rather than electromechanical components.
Pump spa jet pump The jet pump is what moves the spa water.  It consists of the motor, and wet end containing an impeller.  Most modern spa pumps are two-speed designs.  Unions are installed at either end.
Pump Seals Spa pump seal The pump seals separate the wet end from the pump motor, which is the dry end.  Bad seals are a common cause of hot tub leaks.
Spa Parts Catalog
Skimmer Spa skimmer and skimmer basket The spa's skimmer is located at the waterline, and may incorporate a removable skimmer basket (shown).  It is often where the filter cartridge is housed (not shown). The skimmer traps large debris prior to filtration.
Spa Pack/
Equipment System
spa pack A spa pack is the brain and muscle of your spa.  It may include the pump as well as the control system box which consists of the timer and various switching components, as well as the spa's heater.  Spa packs with pumps are referred to as equipment systems or spa skids.
(A) Pump suction (B) Pump discharge (C) Heater coupling
Spa Side spa topside control The spa side (topside) control is the keypad which controls various spa functions such as heater, jet pumps, etc.  It may be electromechanical (air switch), or electronic and may feature a digital temperature readout and thermostat control.  It connects to the control box.
Suction Spa suction fitting The spa's suction assembly (shown exploded view) is typically located in the footwell, and returns water to the pump.  It incorporates a cover to prevent debris entry.  Some spas will have more than one suction fitting as a safety feature.
Repairs Parts Catalog
Thermostat spa thermostat The thermostat consists of a rotating control for setting temperature level, and a capillary tube with bulb attached for remotely picking up the spa water temperature.  The sensor bulb is often housed in a protective thermowell.  For proper operation, the thermostat must be located in the spa plumbing between the suction point and the heater-- never after the heater.
Sensor Mount
hot tub thermowells and sensor mount options A thermowell is a protective housing for thermostat or high limit bulbs, which in turn sense water temperature.  There are several types: (A) is a replacement thermowell for an existing housing. (B) is a self-contained PVC thermowell fitting. (C) is not actually a thermowell, but a sensor mount which allows direct retrofitting of a thermostat sensor by tapping a threaded hole into existing spa plumbing. A sensor mount is often the easiest method for adding a thermostat to a system which does not already have a thermowell.
Hot Tubs Parts Catalog
Union Spa pump unions Pump unions are typically PVC fittings used to mate the pump suction and discharge to the spa's plumbing and heater connections.  The unions facilitate easy removal of the pump when servicing the hot tub.  Pumps utilize the buttress thread type (i.e. MBT = male buttress thread).
Spas Parts Catalog
Valve spa knife valve, spa ball valve Hot tub valves are typically located at the suction side of the pump and at the heater output.  Shown are the knife (slice) style gate valve (A) and the ball style valve (B).  The purpose of these valves is to allow removal of spa equipment without the need for draining the hot tub.
Hot Tubs Parts Catalog
Wet End spa pump wet end The wet end bolts onto the motor to form the pump.  It contains the impeller which moves the spa water; pump seals are located in the wet end.  The front is the suction side of the pump.  Wet ends are available in side discharge (shown) and center discharge configurations.

Hot Tubs Equipment Repair

Spa Depot, The, Spas & Hot Tubs - Dealers, Olympia, WA

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