Water Witch Bilge Switch 101, 12vdc

Water Witch Bilge Switch 101,12v
SKU: 543630
Mfg# 101
UNIT: Each
Voltage: 12vdcNote: Pump Not included
In Stock - Ships out in 1 Business Day


The Water Witch 12volt submersible electronic bilge pump switches allow boat owners to forever rid themselves of the archaic outdated float switch. Instead of an unreliable and short-lived mechanical float switch, our electronic bilge switches have no moving parts and require no adjustments. This eliminates the chance of your battery dying or your pump burning out because of a jammed-on float switch. Temperature, humidity and electrical noise will not effect this switch, nor will it interfere with other electronics. This switch comes with an unprecedented 7 year limed warranty (5 years for Model 101) and is in use by both the Canadian and U.S.Coast Guards.

  • 12V
  • Supports up to 15 Amps
  • 5 Year Limited Warranty
  • 2”W x 1.335”H x 1”D
  • Delay on 6-8 Seconds
  • Delay off 14-16 Seconds



Ratings & Reviews

3 reviews

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jacky patterson


first time to order so I will waite to see what i get.

Best no moving parts boat bilge switch float


I buy these WATER WITCH for all the boats I own. They work perfect, I mount them to the bilge pump as low as possible with zip ties
<br>When you power them up it comes on for 5-10 seconds as a self test. Then it shuts off.
<br>When water touches both the metal pieces it turns on the bilge pump. When water drops below the metal tabs it stay on for another 10-20 seconds to get the last bit of water out.

Old fisherman


It was a like for like product. The original one lasted 14 years. Hope to get at least that long out of this one. Ordering was easy, product was as described, received order a day earlier.


Customer FAQs


How do I replace my float switch with a Water Witch Sensor?

We have prepared a guide to answer this question, to view it click here.

What are the sensors and what are they composed of?

The sensors are 3/4 in diameter stainless steel disks that you see on the front of our switches. They transmit impulses which activate the pump, and turn it off.

Does water need to cover both sensors to start pumping water?

Normally, no. It depends on if the boat is in the water. Looking at the bilge switch with the wires coming out the top, the lowest sensor disk becomes the activation sensor (on model 217,230, and 23 series only, Model 101 and 10 series only have one disk and use the mounting tab as a ground) so the water needs only to barely touch that sensor for 8 seconds to activate your pump. However, if your bilge water is not grounded the water may need to touch both sensors to activate the switch Note: In some cases where there is a lot of rain water entering the bilge, the water may be too clean for our sensor to see. In these rare situations the best course of action is to manually activate the bilge pump to remove the rain water or add mineral (chlorine, salt, bilge cleaners) to the bilge.

What level do you mount the Water Witch bilge switch?

You should install it above the water level left in the bilge after your pump has completed its normal pumping cycle.

Why would the pump turn on when no water is on the switch?

Every time power is initiated to the boat system, or the Water Witch sensor(s), the switch will turn on the pump for 3 pulses. This is normal and is a good signal because it informs you that the system and pump(s) are operational.

How do I hook-up a 3-way switch?

It depends on the pump manufacturer and you should use their instructions. Please Note AUTO Position-Proper voltage must go to our RED wire MANUAL Position – Proper voltage connection must go to our TAN wire What Are The Water Witch Wiring Sequences? Tan Wire Positive (+) side of the pump Black Wire Negative (-) side of the battery Red Wire Positive (+) side of the battery.

What should I use on the electrical connections for best installation?

Connect to a terminal strip, or use quality butt connectors and apply a marine grade liquid electrical tape to prevent water intrusion on your electrical connection.

What size FUSE should I use?

It is important to use the size recommended by the pump manufacturer.

What can be used to clean the stainless steel sensors?

Generally, all that is needed is a wet rag. If your bilge has been extremely dirty, we suggest a quality bilge cleaner and wipe them clean. Do not use wax on the sensors.

Will the Water Witch function with oil or gasoline on the water?

While the Water Witch does not detect oil or gas, it operates with extended time delays. As the water continues to rise, it will lift the oil (hydrocarbons) above the sensors and detect the bilge water. This will activate the pump until the “water” is off the sensors.

How do I test the Water Witch?

Upon correct initial installation, the Water Witch will turn on your pump for 3 pulses  and then turn off. You can use any conductive material (wet rag works best) across both sensors for the delay time (8 seconds) to activate the pump (for the model 101, the second sensor is the mounting tab). Note: Depending on how it was installed, the Water Witch should also turn on when your vessel powers up

Question: During use what is the average current draw from the 12V battery.
Author: Maritin F. 
Answer: The switch itself draws .004 Amps. It can support up to 15 Amps depending on what the pump needs.



The length of the warranty may vary by product, please refer to your product for the exact terms and conditions of the warranty for your purchase.


  • All returns must be recevied within 30 days of receipt of the order.
  • Manufacturer defects reported within 30 days of receipt will be supplied a pre-paid label for return shipping upon approval.
  • Please contact Go2marine LFS Marine and Outdoor for Manufacture Defects, Returns and help with Warranties.