How a hot tub works
Xavier LabelleHow a hot tub works
The hot tub pumps water down from a filter through a system of pipework into a pump/motor which then pumps into a heating element and then
into the hot tub itself.
Controlling the temperature
Water temperature is controlled by a digital keypad on the top side of the spa. The majority of hot tubs have a maximum temperature of 40 degrees C (104 degrees F). Once you have selected the desired temperature the information is communicated to the control unit which regulates the temperature. The user can set temperature, filtration cycle and mode through the console. Control pads have various shapes and button configurations.
Filtration
Your Canadian Spa hot tub is a self-contained unit that does not
require a dedicated water connection and will automatically filtrate the water
without any need for user interaction. By default the filtration cycle will run
for 4 hours every 12 hours and allows your pump to run in low speed mode to
circulate the water. If you have a spa with a second pump or blower these will
also start up and run for a short period to recycle the water within their
plumbing. During this phase the water is drawn in through the filter to catch
large debris and then injected with ozone gas to help remove any harmful
bacteria. Suction filters skim the water for impurities before being drawn
through the pump.
With a Canadian Spa hot tub, you have the option of setting your
hot tub for 2, 4, 6, or 8 hours at 12 hour intervals, or to fc for continuous filtration, which acts as an”auto-cleaning” mode. Keeping your spa clean is a very simple task
when you understand how your spa works and can help save you time and effort.
TIP: The filter/s need to be rotated on a monthly basis to allow a
full flowing system. If you allow the filters to become built up with
contaminants this will then restrict the flow of spa water causing pressure on
your pump. Not allowing your filters to dry after being cleaned will also
cause flow to be reduced.
Ozonators
The ozone works by converting oxygen into ozone. When an air
stream passes a corona discharge (cd) chip or a UV lamp – ozone is created. The
airflow is created through a small tube mounted on the ozonator and on the
airline of the hot tub. The flow created by the pump creates a venturi suction,
which draws oxygen through the ozonator. The oxygen is then transformed into
ozone and added to the water, where it dissolves.
Ozone improves both the water quality in your hot tub and also helps chemical sanitisers work more efficiently.
Heating
Once the water is filtered, it is pumped through the heating
element where the water is warmed to the desired temperature. The heater is
fitted with either a flow switch or overheat high-limit sensors – their purpose
is to read the water flow through the heater so as to prevent the heater from
overheating or going dry due to insufficient water.
Delivering water to the spa
After the heated water has passed through a series of pipes it
reaches the jets. Canadian Spa hot tubs have a variety of sized jets that shoot
the water into the tub. Adjustable jets use air induction that allows warm
water to mix with air which gives you a more pressurised flow.
The jets in a hot tub
Canadian Spa Company carefully designs and places each jet within
the hot tub shell to maximise your spa experience. Using the newest and most
innovative jet systems available, featuring stainless steel ball-bearing
movement for smooth adjustable pulsating massage.
How jets work
Air is mixed with the water by using the air controls creating a
gentle or a most vigorous massage. Water flow is adjusted by simply
turning the outer face of the full sized jets. Our hot tubs have a combination
of pulsating, rotating, and directional adjustable jets.
Diverter valve control
On most spas there is a large diverter valve control located on
the topside of the spa, this valve physically diverts the flow of water from
one jet zone of the spa to the other – enabling more jet power being diverted
to one or more occupants giving them a more powerful massage.
Drainage system
Canadian Spa Company has conveniently located the drain system at
the bottom of the spa for easy maintenance.
Draining your hot tub:
- Start by shutting off the electrical circuit breaker connected to your spa
- Connect a hose to your drain and open the drain valve located at the side of the spa and let the water drain out
- Once the water has stopped flowing out of the drain valve, use a wet/dry vacuum to suck out any remaining water from each jet head (note: if your spa is equipped with a blower, briefly turn the power to the spa back on and run the blower for 10
seconds to remove excess water. shut off the power when finished). - It is recommended to turn off and drain your spa every 3 months, clean and then
refill through the filter housing. This helps to reduce the build-up of
contaminants within the water and reduce reliance on chemical sanitisers.
The main parts at a glance
| Part | What it does | What you might notice if it has a problem |
|---|---|---|
| Filter | Traps debris before water reaches the pump and heater | Weak jets, cloudy water, slow heating |
| Circulation or jet pump | Moves water through the filter, heater and jets | Humming with no flow, noise, no jets |
| Heater | Warms water as it passes through | Water not reaching set temperature, RCD tripping |
| Control pack | The spa's "brain": runs filter cycles, the heater and pumps | Error codes on the topside display |
| Topside panel | Where you set temperature, modes and jets | Buttons not responding |
| Ozonator | Adds ozone to help sanitisers work | Often no obvious symptom; water may need more sanitiser |
| Cover | Holds in heat and keeps debris out | Higher bills, heavy waterlogged cover |
One day in the life of your hot tub
- Filter cycle. At its set times the pump runs on low speed, drawing water through the filter, past the ozonator and through the heater.
- Temperature check. Sensors read the water temperature. If it has dropped below your set point, the control pack switches the heater on.
- Heating. The heater only runs when water is flowing. If flow is too low, a safety switch stops it.
- Your soak. When you press a jet button, the pump switches to high speed and the jets open up.
- Back to standby. After the soak, the spa returns to its filter and heating routine until the next cycle.
Plug and play vs hardwired: what changes inside
The parts are much the same. The difference is how much power the spa can draw at once. A 13 amp plug and play spa runs from a standard outdoor socket protected by an RCD, so it works within a lower power limit. A 32 amp hardwired spa can run more pumps and the heater at the same time, which suits bigger shells and longer soaks. Hardwired installation must be done by a qualified electrician.
Running cost basics
Most of the electricity a hot tub uses goes on heating. The heater replaces heat lost through the cover, the shell and the water you splash out, so the main levers are:
- A well-fitting, insulated cover kept closed between soaks.
- A steady set temperature rather than big swings.
- Sensible filter cycle times, with clean filters so the pump is not working against a blockage.
- A sheltered spot, out of the worst of the wind.
To compare your own costs, check your unit rate against the Ofgem price cap figures.
Frequently asked questions
Does a hot tub need a water supply?
No. You fill it with a garden hose through the filter housing, and the same water is filtered, heated and recirculated until your next water change.
Why does my spa run when nobody is using it?
That is the filter cycle and the heater keeping the water clean and warm. It is normal. Our guide to hot tub sounds explains which other noises are normal and which need a check.
What is the diverter for?
It moves the flow between groups of jets. Leaving it in the middle position gives an even spread. Our guide to single or twin pump hot tubs compares using the diverter with having a second pump.
How often should the water be changed?
Every three months is a good rule, sooner for heavy use or holiday lets.
Choosing a hot tub?
Compare our hot tubs and swim spas, or visit our showroom near Gatwick.