Best RV Tank Flush Valve (2026): 5 Picks Compared

The Camco Dual Flush Pro rinses and cleans RV waste tanks and sewer hoses. Its 3-inch gate valve fits most drain outlets in campers, travel trailers and 5th wheels, and the reverse flush valve backfills and flushes the tank and hose with high-pressure water, breaking up clogs and debris in the plumbing lines. The gate valve has two positions: closed, to flush grey and black tanks while stopping waste from entering the hose, and open, to direct water into the hoses for rinsing. The clear adapter shows when the tanks are clean, and the listing says the product is made in the USA.

Who it's for: RVers without a built-in black tank flush system who want to rinse tanks and hoses after dumping. Who should skip it: owners who only need to replace a leaking 571 check valve.

Its Solar Score of 9.7/10 comes from performance 33/35, build 21/25, value 21/25, safety 7/10 and warranty 3/5: 85 of 100 points, placed on our 9.2 to 9.8 scale.

Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.

What this listing states. Gate valve stops waste from entering the hose, and the backflow stopper guards the grey water hose connection, so safety scores 7 of 10. LIMITED 1 YEAR warranty. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.

Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.

This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

The Lisnhlin is a brass 571-VAC-CHK-A vacuum breaker check valve for B&B Model 571, part of the black tank flushing system installed between the freshwater inlet and the tank flusher. It is rated for water pressure from 8-125 PSI, with 1/2-inch NPT male threads on both the inlet and outlet, and it must be installed a minimum of 6 inches above the highest point of any item connected to the waste tank. It is designed to prevent backflow and back-siphonage, and it suits various RV models, campers, travel trailers and motor homes.

Who it's for: owners replacing a cracked or leaking 571 check valve who want brass construction with a stated thread type and pressure range. Who should skip it: owners whose valve is not a B&B Model 571.

Its Solar Score of 9.7/10 comes from performance 32/35, build 21/25, value 20/25, safety 7/10 and warranty 3/5: 83 of 100 points, placed on our 9.2 to 9.8 scale.

Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.

What this listing states. Prevents backflow and back-siphonage, keeping the freshwater source clean, so safety scores 7 of 10. 1 year manufacturer warranty. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.

Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.

This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

The Yunziling is a brass 571-VAC-CHK-A vacuum breaker check valve for B&B 571 check valves, part of a black water tank flushing system installed between the fresh water inlet and the tank flusher. It is made of brass and can withstand 8-125 PSI of water pressure, and the maker says it is less susceptible to freezing and cracking in cold climates than plastic. It must be installed 6 inches above the highest point of any item connected to the waste water tank, and the maker recommends asking a professional plumber if you are unsure how to install it. It suits all models of caravans and campers, and it prevents the contents of the black water tank from siphoning back into the RV freshwater system.

Who it's for: owners replacing a leaking 571 vacuum breaker who camp in cold climates and want brass construction. Who should skip it: owners who need a stated thread type before ordering.

Its Solar Score of 9.6/10 comes from performance 30/35, build 21/25, value 20/25, safety 7/10 and warranty 3/5: 81 of 100 points, placed on our 9.2 to 9.8 scale.

Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.

What this listing states. Prevents backflow and back-siphonage, keeping black tank water from mixing with grey water and freshwater, so safety scores 7 of 10. 1 year warranty. It does not say everything a buyer needs, such as who pays return shipping, so warranty scores 3 of 5. See How We Pick.

Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.

This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

The NOVINO is a 571-VAC-CHK-A vacuum breaker check valve for the black tank flush system, installed between the freshwater inlet connection and the tank flusher. It is designed to keep what is in the black tank from siphoning back into the RV water supply, and it works at 8-125 PSI with 1/2-inch NPT male threads on both the inlet and outlet. It replaces a failed leaky valve when the black tank flush line was blocked or faulty and leaking and wet the camper trailer floor. No warranty term is stated.

Who it's for: owners who need a direct 571 replacement with a stated thread type and pressure range. Who should skip it: owners who want a stated warranty term or a stated material, since this listing gives neither.

Its Solar Score of 9.5/10 comes from performance 29/35, build 19/25, value 20/25, safety 7/10 and warranty 0/5: 75 of 100 points, placed on our 9.2 to 9.8 scale.

Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.

What this listing states. Prevents backflow and back-siphonage, keeping the black tank contents from siphoning back into the RV water supply, so safety scores 7 of 10. No warranty term, so warranty scores zero. See How We Pick.

Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.

This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.

The Vypart kit is a 31705 RV toilet water valve kit designed for Thetford Aqua-Magic V high and low RV toilets, including hand-flush and foot-pedal flush models, and it is compatible with a wide range of models including 31653, 31688 and 31705. The kit includes the 31705 toilet water valve, a rubber flange seal and screws. It uses a robust valve body with a sturdier cover, thicker body and tighter thread, plus an added layer of elastic fiber material inside, and the maker says it resists hydrolysis, chemicals and frost, and that more than 400,000 RV toilet water valves have been sold. Installation needs only a Phillips screwdriver.

Who it's for: owners of a Thetford Aqua-Magic V toilet with a leaking water valve. Who should skip it: buyers shopping for a black tank flush valve.

Its Solar Score of 9.3/10 comes from performance 21/35, build 20/25, value 18/25, safety 0/10 and warranty 0/5: 59 of 100 points, placed on our 9.2 to 9.8 scale.

Taken from the seller's listing on 14 November 2026. Capacity and output figures are rated by the manufacturer.

What this listing states. This product does not plug in or run on a battery, so safety is not part of its score. No warranty term, so warranty scores zero. See How We Pick.

Follow the manual. Connect and use the product as the maker describes, stay within every stated rating, and read the manual before first use.

This is general buying information, not professional advice. Follow each product manual and local rules, and see our Safety Disclaimer.