The Workings of the Spa Pump
Spas or hot tubs are only good when their water is clean and when their jets can shoot out water with sufficient pressure. In order to assure these, it is necessary to have a functioning pump with enough horsepower to keep water circulating at a vigorous rate. The horsepower rating will vary with the size of the spa, but regardless of the size, spa pumps perform the same functions.
To keep the water clean, spa water must constantly pass through the installed filters. This is because every time you use your spa, you inevitably leave behind dead skin, body oil, hair, and sweat, not to mention your perfume and cologne. Although you may keep your spa covered at all times while not in use, dirt and debris can still drift into it while you are basking in its hot waters.
The spa pump draws water from the tub and forces it through the filter thus removing any extraneous materials floating in it. Depending on the type of filter, this is done before of after the pump and heater. Filters installed before the pump are called suction filters while those after both the pump and heater are referred to as pressure filters.
There are three main components of the spa pump –the intake nozzle, impeller, and motor. It is through the intake nozzle that water enters the pump. A pipe leading to the tub for access to the water is affixed to it. From there water flows through a spiral chamber to the impeller. It is because of this chamber that the pump’s casing is called a volute.
The impeller is what forces the water from the pump and eventually back into the tub. It is in a section of the pump called the wet end. The impeller functions like the propeller of a fan and is indeed similar in construction. As it rotates, the water brought in through the nozzle is agitated and forced out of another opening in the pump under strong pressure. It is rotated by an electric motor located in pump’s dry end section.
With this circulation, water is continually filtered thus keeping your spa water clean. It is, however, necessary to periodically clean or replace your filters to get the trapped substances out of the system. It is also this pressurized flow that makes the delivery of strong bursts of water into the tub through the jets.