Do you worry about your vacuum pump running endlessly?

Flush Guard protects your vacuum pump and ends your worry. With Flush Guard, your vacuum toilet pump runs only when you flush, never when it leaks. Great with guests, when underway, and eliminates the need to turn off the toilet when you’re away.

How does Flush Guard work?

The Flush Guard replaces your existing mechanical vacuum switch and electronically monitors the vacuum in the system to detect leaks. When a leak is detected, the pump is turned off, and will not run until the Flush Guard is reset. Resetting the Flush Guard allows the pump to run again, and is accomplished by momentarily turning off power (using a switch or circuit breaker) to the pump motor, or by pressing and holding the optional indicator/switch for 1 second.

If vacuum has not been lost, the toilet will operate as normal. Flushing will be detected, and the pump will run automatically until sufficient vacuum is developed.

If no or low vacuum is present when the toilet is flushed, or the pump does not run, reset the Flush Guard by turning the power off and back on. If desired, the Flush Guard can be reset each time before the toilet is used.

Add the optional indicator/reset switch

The optional indicator/switch provides a simple way to see when the vacuum has been lost, or the pump was unable to establish sufficient vacuum. When this is the case, the indicator will flash. Pressing the indicator/switch will reset the Flush Guard.

The indicator/switch shows the following codes:

OffFull vacuum – Toilet is ready to use
Single FlashFull vacuum was reached, but then was lost due to a leak
Double FlashFull vacuum could not be achieved
Steady OnThe pump is currently on

Can Flush Guard be installed in place of any mechanical vacuum switch?

Flush Guard replaces all Dometic and Sea Land vacuum switches including :

  • 385318032 (S-Series)
  • 385310540 (VG II, VG2)
  • 385311216(VG4)
  • 385311436 ((low-profile VG, VG3/VHT)
  • 385311187 (CVT Marine) and others

How is Flush Guard Installed?

The Flush Guard replaces the mechanical vacuum switch that is installed on the vacuum accumulator tank. Electrical wiring is unchanged, and no additional wiring is required.  Installation time is typically 10 minutes.

Flush Guard comes with all of the hardware required for most installations. You’ll need a few common hand-tools, a multi-meter and a small amount of silicone RTV sealant to complete the installation. See the Flush Guard Installation Manual for more information.

Included with Flush Guard:

  • Flush Guard module
  • Aluminum baseplate
  • Silicone gasket
  • 10-32 threaded/barbed hose fitting
  • 2″ of 3/32″ ID silicone tubing
  • Two #8 x 7/8″ stainless steel machine screws
  • Two #8 x 3/4″ stainless steel machine screws
  • Four #8 stainless steel lock washers
  • Four #8 stainless steel flat washers
  • Four #8 stainless steel nuts
  • Four #8 fiber washers
  • Installation manual

Included with the optional indicator/reset switch:

  • Stainless steel water-proof indicator/reset switch with hardware and 15’ marine grade wiring
  • “Toilet” and “Press if Flashing” labels
  • Two #6 Ring Terminals

Where can I purchase a Flush Guard?

Flush Guard may be purchased by contacting GRT Avionics at 616-245-7700 or The current retail price is $250. The optional Indicator/Reset switch is available for $39.

Flush Guard – Protect your pump, end your worry!

  • Vacuum pump will not endlessly run or cycle on and off due to leaks
  • Easily re-settable by cycling power via existing switch or breaker
  • Electronic – No mechanical parts to wear out
  • Connects to existing wiring
  • Safely allows leaving pump on when away
  • 5-year warranty
  • Waterproof
  • Works with 12 to 32V systems
  • Optional Stainless Steel Indicator-Switch provides an attractive status indicator/reset control

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