When choosing a primary or secondary bilge pump for your boat, there are many factors to address, such as gallon-per-hour rating, mounting location, cartridge versus non-cartridge, quantity, and brand. With an ocean of articles covering these subjects, I’m skipping ahead to an aspect of bilge pump selection less commonly addressed: choosing a bilge pump system and component type that’s most ideal for your boating routines and needs, primarily dealing with automatic versus manual bilge pumps, and the switch options and variations to control the pumps.
Since slight variations in terminology can indicate different products/traits, it’s important to understand the different primary components most commonly used for standard bilge pump systems:
Float-switch: mounts to the bottom of the bilge, which works much like any other float-switch; when water levels increase, the float is raised, which activates the the pump. Manual Bilge pumps that utilize float-switches become automated, and are commonly referred to as “automatic bilge pumps”
Bilge pump switch (non-float): mounts to the dash. Depending on the switch, you’ll have the option of “on/off” or “Auto/Manual/Off”. “Manual” or “On” will be for when you want the pump on, regardless of water level readings by the pump (or float-switch). Auto will activate the functionality of the float-switch or built in sensor, allowing the bilge-water removal process to be automated.
Automatic Bilge Pump: have built-in water sensors that periodically turn on to check for water. If water is present, the pump will activate. The sensor will usually turn on once every few minutes. The advantage of automatic bilge pumps is that you get an automated water evacuation system without requiring any components other than the pump and wiring hardware to connect to the electrical system, which is simple and takes up minimal space. The biggest disadvantages of an automatic bilge pump, assuming it’s not connected to a bilge pump switch, is that if the pump is not disconnected from the battery, it’s sensor will continue to periodically activate. If you store your boat outside of the water, this feature becomes pointless and will slowly drain your battery. The second disadvantage is the lack of manual on/off control, though there are some exceptions
Manual Bilge Pump: activated by either a float-switch or a (dash mounted) bilge pump switch. If a float-switch is used, the pump becomes an “automatic” bilge pump, but rather uses a float-switch to activate the pump rather than the water sensor. It’s common for manual bilge pumps to be sold with float switches and be labeled as as “Automatic”. If you have a system consisting of manual bilge pump, float-switch, and bilge pump switch, you’ll have full control of how and when the pump activates. The auto feature will use the float-switch to activate the pump, with on/off turning the pump on/off regardless of float-switch readings.
With the above components options, you have several ways you can choose to manage your primary or back-up bilge pumps system:
- Manual bilge pump with 3 way pump switch and float-switch: complete control of your pump including choice of automated water evacuation.
- Manual bilge pump with float-switch: Bilge pump becomes automatic, but doesn’t allow for direct on/off control.
- Automatic Bilge pump with 2 or 3 way pump switch:Automated bilge pump with the ability to turn it completely off. Some Automatic pumps give the ability to manually turn the pump on, which would have the same results as a manual bilge pump system that uses both a float-switch and a bilge pump switch.
- Automatic Bilge Pump with no switches: Automated bilge pump without the ability to manually turn on or off (some exceptions) and will drain battery if not disconnected.
Relatively speaking to the rest of boating, bilge pumps and components are exceptionally inexpensive, making not “cheaping-out” almost painless.
If you’re in the market, we carry bilge pumps from Rule, Johnson, Attwood and SeaSense who all offer a wide variety of top quality pumps, cartridges and switches. Addionally, with the iboats.com Low Price Guarantee, you can be sure to get the very best price available.