Jabsco Twist ‘n’ Lock Manual Marine Toilet

The Jabsco Twist 'N' Lock Manual Marine Toilet is a raw-water toilet for powerboats and sailing craft, available as the compact 29090-5000 or household-style regular 29120-5000. Both models use a self-priming, double-acting piston pump, 19mm flushing-water inlet and constant 38mm waste path. The 90° locking handle closes the waste outlet valve after pumping to help guard against siphonic flooding and waste backflow.

Designed specifically for marine sanitation systems, the Jabsco Twist 'N' Lock toilet can be installed in power or sailing craft, either above or below the waterline when correctly plumbed. Waste can be discharged into an onboard holding tank, a suitable treatment system or overboard where national and local regulations permit.

The hygienic white vitreous china bowl is supplied with a standard-close baked-enamel wooden seat and cover. The pump and base use corrosion-resistant moulded components, with stainless steel fastenings and marine-suitable seals and internal components.

Model Options

• 29090-5000 – Compact Bowl: Space-saving circular bowl profile measuring 324 × 396mm. Overall dimensions are 330mm high × 445mm wide × 425mm deep. Replaces the Jabsco 29090-3000.
• 29120-5000 – Regular Bowl: Household-style elongated bowl profile measuring 365 × 460mm. Overall dimensions are 350mm high × 470mm wide × 485mm deep. Replaces the Jabsco 29120-3000.

How Does Twist 'N' Lock Work?

After the toilet has been pumped clear, rotate the handle through 90° to engage the Twist 'N' Lock mechanism. The pump piston then closes the waste outlet valve, helping prevent waste from flowing back into the bowl and reducing the risk of siphonic flooding.

Turning the handle back to its normal operating position releases the lock so the toilet can be pumped again. The locking handle supplements the correctly installed sanitation system; it does not replace seacocks, vented loops or other required anti-siphon protection.

Pump Operation and Performance

The manually operated pump uses a long-stroke, double-acting piston mechanism. Its angled housing and contoured handle reduce the effort required during pumping, while the flush-control lever operates an automatic vacuum breaker to assist bowl emptying.

• Flushing pump self-primes from dry with the water source up to 1m below the toilet base
• Waste pump discharges up to 3m above the toilet base
• Strong swirl action distributes flushing water around the bowl
• Constant 38mm waste path helps minimise blockages
• Full-bore aortic joker valve provides automatic backflow control
• Spring-assisted top-valve closure helps the pump prime
• Flush-control lever selects wet-bowl or dry-bowl operation

Construction and Materials

• Hygienic white vitreous china bowl
• Baked-enamel wooden seat and cover
• ABS or polypropylene pump and base
• Selected acetal-resin internal components
• Passivated 316 stainless steel fastenings
• Brass valve weights
• Neoprene seals and gaskets
• Crevice-free contours and skirted base for easier cleaning
• Front- and top-facing fastenings for maintenance access
• Renewable external seal housing
• Dual-function base plug for draining and cleaning access

Installation and Plumbing

Both models are supplied with the pump positioned for right-hand operation. The bowl and pump assembly can be reconfigured before installation to position the pump on the left-hand side.

The multi-angle discharge elbow can be rotated through 360° before the hose is connected, allowing the outlet to be aligned with the boat's sanitation pipework.

• Flushing-water inlet: 19mm (3/4") internal-diameter hose
• Waste outlet: 38mm (1-1/2") internal-diameter hose
• Flush-water source: Sea, river or lake water only
• Discharge: Holding tank, treatment system or permitted overboard outlet

Use reinforced, smooth-bore sanitation hose and secure each relevant hose-tail connection with appropriate stainless steel hose clamps. Keep hose runs short and avoid sharp bends that could restrict flow or increase pumping effort.

Can This Toilet Use the Boat's Fresh-Water System?

No. The Jabsco 29090-5000 and 29120-5000 are designed for raw-water flushing only. They must not be connected to the vessel's pressurised fresh-water or potable-water system.

Fresh water can be poured into the bowl manually when priming or servicing, but the toilet's inlet pump must be supplied through a correctly installed raw-water inlet system.

Key Features

• Genuine Jabsco Twist 'N' Lock manual marine toilet
• Available with compact or household-style regular bowl
• Manual double-acting piston pump
• 90° locking handle closes the waste outlet valve
• Helps guard against siphonic flooding and waste backflow
• Automatic vacuum breaker assists bowl emptying
• Strong swirl-action bowl rinse
• Self-priming flushing pump
• Waste discharge capability up to 3m above the base
• Constant 38mm waste path helps reduce blockages
• Full-bore aortic joker valve with automatic backflow control
• Pump can be configured for right- or left-hand operation
• 360° adjustable discharge elbow
• Front- and top-facing fastenings simplify servicing
• External seal housing provides accessible seal replacement
• White vitreous china bowl
• Standard-close baked-enamel wooden seat and cover
• Suitable for installation above or below the waterline
• Compatible with holding-tank or permitted overboard-discharge systems
• Raw-water flushing only

Which Jabsco Manual Toilet Should I Choose?

Choose the Jabsco 29090-5000 compact toilet where floor area and installation clearance are restricted. Its shorter depth and narrower overall width make it suitable for smaller marine heads.

Choose the Jabsco 29120-5000 regular toilet where household-style seating comfort is the priority and sufficient installation space is available. The pump system and plumbing sizes are the same; the primary difference is the bowl and seat size.

Servicing and Maintenance

Jabsco manual toilets are designed to be serviced without specialist tools. All principal fastenings face forwards or upwards, while the external seal housing allows the piston-rod seal to be replaced without dismantling the complete toilet.

• Major service kit: Jabsco 29045-3000
• Seal housing assembly: Jabsco 29044-3000
• Winterisation: Drain the toilet and connected pipework completely
• Cleaning: Use non-abrasive cleaners suitable for ceramic and enamelled surfaces
• Avoid: Acetone, neat bleach, aggressive chemicals and abrasive pads

Important Installation and Safety Information

Install full-bore marine seacocks on any relevant through-hull connections and position them where toilet users can reach them. A correctly positioned vented loop is required wherever the toilet rim or connected pipework may fall below the waterline.

The Twist 'N' Lock handle and flush-control lever must not be treated as substitutes for seacocks. Close the inlet and outlet seacocks after use and whenever the vessel is left unattended. Overboard discharge must comply with all applicable local and national regulations.