100TECH Marine Fuel Sending Unit Float Replacement 24in - Durable Reed

In this review of the 100TECH Marine Fuel Sending Unit Float Replacement 24in, the bottom line is simple: this is a practical, durable replacement sender for boat and RV owners who need a reliable level sensor without fiddly adjustments. The unit stands out because it uses an imported OKI reed switch rather than a swim arm thick-film design, which translates into fewer moving parts and better long-term reliability. Installation is straightforward and the package includes a gasket, mounting screws and clear wiring instructions so fitment is quick for anyone comfortable with basic tank work.

Key Features

• OKI reed switch: Provides improved durability and reliability over thick-film swim arm senders because there are no fragile moving contacts to wear out.
• 240-33 ohm output: Matches the American standard gauge range so it reads 240 ohms at empty and 33 ohms at full for straightforward compatibility.
• 316 stainless steel construction: Heavy duty materials and rugged build resist corrosion in marine environments and extend service life.
• Complete installation kit: The sender ships with a gasket, mounting screws and illustrated instructions, making installation easier for DIYers and technicians alike.
• Standard SAE 5-hole pattern: Fits common mounting locations without needing custom adapters on many fuel tanks and water tanks.
• Float size and hole guidance: The float is 1.38in diameter and a 1.50in hole is recommended if drilling is required, giving clear installation parameters.

Who It's For

This sender is best suited to boaters, RV owners and automotive hobbyists replacing an arm type fuel sender who want a dependable, low-maintenance sensor. It is particularly useful for those with 24in tank depths who prefer a sealed reed switch solution and straightforward electrical compatibility with 240-33 ohm gauges.

Those who should look elsewhere include owners who need a custom length not listed; while other lengths are available by contacting the seller, buyers needing immediate or highly specialized probes may prefer a custom manufacturer. Also, users expecting digital smart-gauge features or telemetry should consider dedicated electronics rather than this analogue sender.

Pros & Cons

Pros

• Durable reed switch design reduces risk of mechanical failure compared with swim arm types.
• Solid build quality with 316 stainless steel and neat heli-arc style welds noted by customers.
• Easy installation with included gasket, screws and clear wiring instructions.
• Direct compatibility with 240-33 ohm gauges for a reliable reading range.

Cons

• Only available in specified lengths up to 24in unless you contact the seller for other sizes, which adds a step for nonstandard tanks.
• Float diameter and recommended hole size require a 1.50in opening if drilling, which may not suit all retrofit situations.

Specifications

Brand	100TECH
Output	240-33 ohms (240 empty, 33 full)
Length	24in (610mm)
Material	316 stainless steel construction
Mounting	SAE 5-hole pattern with gasket and screws
Float diameter	1.38in (35mm); drill hole 1.50in (38mm) if required
Warranty	1 year limited plus free technical support

Our Verdict

The 100TECH 24in marine fuel sending unit is a sensible, cost-effective replacement for arm type senders, offering strong build quality, simple installation and reliable readings thanks to the OKI reed switch. It represents good value for boat and RV owners who need a durable analogue sender that fits standard gauges and common mounting patterns.

Frequently Asked Questions

Will this sender work with my 240-33 ohm gauge?
Yes, it is built to the American standard 240-33 ohm range and is designed to be compatible with gauges that expect that resistance curve.

Can I order a different length than 24in?
The listing covers lengths from 4in to 24in and the seller asks customers to contact them directly for other lengths beyond that range.

Is the unit suitable for marine use?
Yes, the heavy duty 316 stainless steel construction and sealed reed switch design make it appropriate for fuel or water level sensing in marine environments.