Lets start with the basic facts: if your central vacuum uses a real central vacuum motor you do not need to worry about a suction relief valve. True central vacuum motors do fail for various reasons, but they do not under normal operation overheat and “burnout” from a clog in the system. Modern central vacuum power units already include a manufacturers built-in overheat protection system, some units even have more than one .
Auxiliary motor protection or suction relief valves sold as a “necessary part” by some online dealers are a cheap attempt at trying to make a few extra bucks. If a website promotes the use of suction relief valves it’s likely they are trying to pass off inferior central vacuums using cheap thru-flow motors from portable vacuum cleaners. True central vacuums use bypass motor systems and do not require suction relief valves.
The “motor protection” or “suction relief” valve is largely an internet product that gives our industry a bad name. Ask most professional CVS installers for a “motor protection” valve and you will receive a puzzled look. Your new central vacuum is already protected from overheating, usually with a thermal breaker either built into the motor or the control board.
The thermal breaker is much more effective and more reliable. Thermal protection requires no adjustment or settings and self resets once the motor compartments temperature falls to a safe level. Using a “suction relief” valve does just that, relieves your system of it’s suction when it is not necessary and may be harmful. If you suck up an object while your cleaning and it should become lodged in the tube system while traveling to the vacuums collection bin your “suction relief valve” will open the vent and the object will stop. Instead of applying more suction, which is what happens naturally in central vacuum systems, the “suction relief valve” switches the suction to an open vent and the object has now become a problem clog.
These devices are at best a nuisance which provide no value or protection and need constant tinkering. Many folks end up adjusting the valve so it never opens, or removing it from the system completely. It should also be noted that Hide-A-Hose systems can not tolerate a “motor protection” valve as they require full suction from your vacuum system to operate correctly.
Who should use a suction relief valve?
If your central vacuum power unit uses a portable vacuum motor (also called a thru-flow or “true-flow” motor) and does not have built-in overheat protection then an Airflow Relief valve is helpful. Whats better is to only use a central vacuum system which uses a true central vacuum bypass motor. Most “better than builders quality” central vacuums use bypass motors. All Aspria central vacuum power units
use only bypass vacuum motors.
There is a site that uses an image of a home on fire to sell their “motor protection valve”. I am not kidding. It is really stupid that some would resort to that in an effort to squeeze an extra twenty bucks from a customer. Get a real central vacuum with a bypass motor and save your money on “motor protection” or “suction relief” valves. In the next stinker product review we will be discussing the Tornado Power central vacuum “maintenance cloths”. In a word; Pee-Yew!