U.S. Patent No. 11,320,172
Air conditioner shut-off system and method to prevent drainage overflow
- Filed
- Issued
- Inventor
- David Todd Walker, Jr.
AC Flood Guard GraviTrip™
A gravity-activated shutoff for A/C overflow.
GraviTrip shuts off HVAC equipment when the condensate drain line clogs, backs up and fills the collection bottle. It works on weight, with no float mechanism.
See how it works
Three steps from overflow to shutoff.
Under normal conditions the bottle stays empty and the system runs as usual. GraviTrip acts only when overflow water has somewhere to go: into the bottle.
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Drain-line backflow fills the bottle
If the condensate line clogs or backs up, overflow runs through 3/4-inch PVC and the L-adaptor into the collection bottle.
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Water weight triggers the switch
At the set fill level, the added weight pulls the factory calibrated chain and physically actuates the weight-activated switch.
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24 V control circuit shuts off the HVAC
Wired in series on the 24 VAC R lead, the switch opens the control circuit and the system stops running.
What's in the box
A complete kit for one installation.
Every part is listed on the packing insert so installers can check the kit before they start.
| Qty | Item |
|---|---|
| 1 | Switch box assembly with UL 61058-rated switch, UL 94 V-1-rated switch box and wiring leads |
| 1 | Bottle hanger |
| 1 | Collection bottle |
| 1 | L-type adaptor (antimicrobial, to reduce algae buildup) |
| 1 | Chain assembly (factory calibrated length) |
| 1 | Chain clip |
| 2 | Mounting screws |
| 1 | Pair of 18 AWG UL 1007-rated red and black wire leads |
| 1 | Instruction and warning insert |
Specifications
Built for indoor 24 VAC systems.
| Function | Shuts off HVAC equipment when the condensate drain line clogs, backflows and fills the collection bottle |
|---|---|
| Activation | Gravity (weight) activated. The switch is factory calibrated to trip at a specified suspended load that includes the full factory chain. |
| Application | Indoor HVAC equipment with a 24 VAC low-voltage control circuit, where permitted by the equipment manufacturer |
| Control connection | In series on the 24 VAC R (red) control lead. Not for 120/240 VAC line voltage. |
| Drain connection | 3/4-inch PVC, with the L-type adaptor bonded using approved PVC cement |
| Components | UL 61058-rated switch, UL 94 V-1-rated switch box, 18 AWG UL 1007-rated wire leads |
| Mounting | Two mounting screws, into a stable support that holds at least 2.2 lb |
| Reset | Empty the bottle, refit it, then gently pull the chain |
| Maintenance | Test the switch and inspect the installation every six months and after any HVAC service. Clean with mild soap and water only. |
| Installation | Professional installation only, by a qualified HVAC technician or licensed electrician |
| Warranty | 3-year limited warranty, covering switch failure only |
A second line of defense
Safety float switches can fail. GraviTrip adds another layer.
Many air handlers rely on a float switch at the condensate line or in the emergency pan. With only 42% of homeowners having a professional service their A/C regularly, drain lines often go uncleaned and float switches go untested.
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Regular drain-line maintenance
A professional cleans the condensate drain line.
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Safety float switch
A float in the drain line or emergency pan rises with the water.
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GraviTrip gravity-activated shutoff
A supplemental shutoff that trips on the weight of overflow water collected in the bottle.
Patented technology
U.S. Patent No. 11,692,736
Air conditioner shut-off system and method to prevent drainage overflow
- Filed
- Issued
- Inventor
- David Todd Walker, Jr.
Important limitations
GraviTrip is a supplemental safety device, not a leak detector. It does not detect leaks outside the collection path, internal evaporator-pan overflows that aren't routed to the bottle, freezing, power loss, or improper installation. Professional installation only, on indoor 24 VAC low-voltage HVAC control circuits.
Add GraviTrip to the systems you service.
Ask about pricing and availability, or work through the installation guide step by step.