Check your secondary bilge pump and high water switches

This winter during annual maintenance checks I found both the secondary bilge and high water sensors/switches had failed on our 4 year old classic R27. They are both SPX Ultima switches. I was extremely surprised to find two critical solid state switches had failed. How they even fail I have no idea since there are no moving parts. I cut them open for failure analysis and found no indication of failure mode whatsoever. These two sensor/switches are really hard to access on the classic R27 so I suspect they are not often checked on a lot of boats. I don’t know if that is the case on the other models but I highly recommend these switches be checked regularly.

Here are a few items to consider when testing these systems for those that may not be familiar with them.
- both bilge pumps have two power sources drawn from separate batteries. The switches on the 12v breaker panel are powered from the house battery and bypass the Ultima switch and fuse connection from the thruster battery. This allows the pumps to be manually activated even if the Ultima switch has failed, thruster battery is dead, or the fuse (to the thruster battery) is blown. Testing the pump by activating the breaker switch does not ensure the Ultima switch has power or is working.
- the high water alarm dashboard control has a “test” position. This only tests the audible alarm. The Ultima switch nor the warning light are tested. There is also an “off” position. This only turns off the audible alarm the warning light will still light in the off position if the system is functioning properly. I made a “key” to lock the switch in the armed position.
- the Ultima switch has two raised circles on the side of the switch. To test the Ultima switch you can put two fingers on the raised circles to start the pump. If that doesn’t work you can remove the switch and drop it in a container of water. If that still doesn’t work it is either a bad switch, blown fuse, or loose battery connector.
- on the classic R27 the secondary (#2) bilge pump and the high water alarm switch are mounted on or next to the bulkhead wall in front of the engine. Access is via under the step so the the inspection should be done along with the impeller and or belt changes.
- removing the switch from the bilge pump to drop into a container of water or replace it is easy once you get access. You can grab the switch and pull straight up and it will come out of the bracket. Removing the high water switch is much more troublesome as it is screwed to the bulkhead. There are two square head screws. A small ratcheting wrench that will accept a square drive bit is what I used as there is no room for a screwdriver handle. This is all done blind (by feel) as you cannot see the switches from that angle (at least I can’t).

Just thought I would share to maybe save someone’s boat! The good news is that the switches don’t cost much. All the rest is not fun though.

Curt

Great info. as always Curt. With boat in the water could you test by pulling the fuse for the primary pump and dropping a hose in the bilge or is the level above an acceptable point? If you want to drop the switch in a bucket how long is the connection wiring or are you disconnecting and testing with a multimeter?

I test the primary using a stick with a rag wrapped around it. Easier on my back than hanging in the bilge.lt also cleans the sensors. I had an issue at one point where the bilge cleaner foamed and kept the pump running.

I keep a pretty close eye on these on my 23. They are easy to access and easy to test (sorry Curt ;-) so they are on my pre departure checklist. One finger on each circle and voila, tested. I might have to wet my fingers every once in a while but that has been it. They have worked until this winter.

This year when prepping for winter I drained the hot water tank into the bilges. Didn’t pay any attention to it as I had some other things to do. 15 minutes later I am back in the starboard compartment putting the drain plug back in the heater when I thought about the bilge. I hadn’t heard the pump so figured I would lift the center hatch and check. Crap, water sitting there. My first thought is that it wasn’t enough to trip the switch but upon a visual check, the switch was completely submerged. I tried the finger test, under the water, and the thing started right up.

I haven’t yet messed with this any more but feel like the clean water from the tank was too clean to trip the sensors on the switch. Once I put my fingers in there there was enough of a path that the sensors tripped. Not sure why but it will need some thought and experimentation. I only boat in saltwater and I know the switch works in that environment as I inadvertently “tested” it this summer through non-catastrophic user error ;-)

Just putting it out there as it is pertinent to this thread.

Chimo":25csn833 said:

Great info. as always Curt. With boat in the water could you test by pulling the fuse for the primary pump and dropping a hose in the bilge or is the level above an acceptable point? If you want to drop the switch in a bucket how long is the connection wiring or are you disconnecting and testing with a multimeter.

Click to expand...

Hi David!

I thought of disabling the primary but the secondary is pretty high up and I didn’t want to fill the bilge with that much water. Don’t know if it would start to cover anything you wouldn’t want but I think it would be pretty close. It would take a long time to fill as well. I wouldn’t recommend that approach especially when there are other better alternatives.

Yes, there should plenty of wire to pull the switch and drop in a container as long as you put the container down near the pump. You can also cut the tie wraps and then pull the switch up further. I did also check with a multimeter after cutting the wire to confirm it was bad but I would only do this after all else has failed. As stated the high water alarm is more of a pain because it is screwed to the bulkhead.

Curt

I am not sure why these sensors keep failing. I have probably installed five between the high water and the primary. I have been looking for a different brand, but they all seem to have more than two wires for operation and the Johnson has just two leads. Such an important element for boat safety and it seems to be the weakest link.

knotflying":ognglo3d said:

I am not sure why these sensors keep failing. I have probably installed five between the high water and the primary. I have been looking for a different brand, but they all seem to have more than two wires for operation and the Johnson has just two leads. Such an important element for boat safety and it seems to be the weakest link.

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Agreed! I was convinced I had to be doing something wrong in the testing. How can two solid state electronic parts fail with no water intrusion, over current, or other visible cause? It’s a mystery to me!

Really good information about the bilge pumps and sensors. I’m sure our automatic switches aren’t working so I’m ordering three new ones. Before I replace them I’d like to check the fuse for the sensors first but I’m not sure where it is. Both pumps work fine when I turn them on at the circuit breaker panel but I have a feeling the sensors are bad. Thanks in advance.

Tim and Donna
Gratitude R27

The high water switch and #2 bilge pump switch are both powered via an in-line fuse (in a rubber holder labeled bilge pump #2) below the Thruster battery switch in the port side cockpit locker on our 2014 Classic R27. The breaker at the helm is powered via the house battery supply to the breaker panel.

FYI

Last year when I replaced my aft bilge pump, I replaced it with the same style Johnson pump with a mechanical float switch attached. It worked all season without problems, unlike the solid state switch.

Thank you for all the great feedback, gotta love Tugnuts! I’ve ordered two new sensors (I already had one in my spares box) so I’ll be installing them as soon as they arrive. This hasn’t been a big issue for us because Gratitude is stored inside when we’re not using her, but this year will be a little different. The green algae kept us off the water last year but this year we are talking about leaving her in the water at different marinas around Florida so we can explore new areas. We’ll see how that works out.

Tim and Donna
Gratitude

Hi All,
Interesting thread. I have the R23 and my switch just failed. I knew it failed because it failed in the on position. I keep the 23 in the driveway (fully covered) and while walking by it one evening I heard the bilge on. Sure enough the unit has failed. I immediately removed it and took it apart (smashed it open 😀 ), inside the electronics were damp. My bilge is always dry but live in the ‘wet coast’ so I suspect these units are not truely ‘sealed’ and are breathing in moist air as the temp and humidity charges. As an experiment I’m going to use a Marine seal/adhesive and completely seal the unit, I recommend you all do the same.

As a matter of practice I remove the bilge plug and the fuse for the bile pump when I store on the trailer. I found that even with the bilge plug removed the water does not fully drain at times and the pump can engage.

Also, As family guy has stated, I suspect that water is infiltration the sensor somehow. The only source that I observed is where the wires enter the unit. Although it looks like a tight fit, I swabbed silicone sealant around the whole area. Stay tuned.

knotflying":1su6seb7 said:

... I suspect that water is infiltration the sensor somehow. The only source that I observed is where the wires enter the unit. Although it looks like a tight fit, I swabbed silicone sealant around the whole area. Stay tuned.

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Water infiltration would definitely be a problem. However, there is some other failure mode going as well as both of my failed sensors had never been under water or even been sprayed by water of any sort. I opened them up and found no sign of moisture inside or any other indication of failure cause. Interesting, my primary sensor on the number one bilge pump often sees a lot of water and yet has never failed.

The electronic switches that was factory installed on my R-25 is especially sensitive to oil fumes. Over time, it seems impossible to keep a small amount of exhaust from accumulating on the sensors - causing one to fail closed and another one to fail open, not making connection when tested with a cup of water poured over it.

I replaced the switches with RULE switches - no more problems. I know RULE have their own problems, but the testing seems to be reliable.

Which rule did you use?

I used Rule-a-Matic model 35A

Well suited to my R25 because the base can be separately attached in the bilge and the switch snaps into the base after wiring.

Been reliable for 2 plus years



Stuart Bell
Ranger 25: Shearwater
(561) 352-1796

I used a 35A. It comes into pieces so you can install the base and just snap the top in. That way the wires don’t get in the way when you’re putting the base on.

Familyguy":2jetqb5f said:

Hi All,
Interesting thread. I have the R23 and my switch just failed. I knew it failed because it failed in the on position. I keep the 23 in the driveway (fully covered) and while walking by it one evening I heard the bilge on. Sure enough the unit has failed. I immediately removed it and took it apart (smashed it open 😀 ), inside the electronics were damp. My bilge is always dry but live in the ‘wet coast’ so I suspect these units are not truely ‘sealed’ and are breathing in moist air as the temp and humidity charges. As an experiment I’m going to use a Marine seal/adhesive and completely seal the unit, I recommend you all do the same.

Click to expand...

Exelent plan !!