Bilge Pump and Float Switch in Frozen Water

[Claude L.-Auger]

Poster said boat is on the hard with batteries connected and to get charged periodically over the winter. So the bilge pump will start as currently set-up. But that does not prevent freezing. I would empty the bilge and the hose, disconnect the pump and add antifreeze in the bilge. Since you plan on visiting it is then easy to check situation.

 

[dLj]

No need to remove the batteries. Just make sure they are fully charged and watered. Then completely disconnect them. Cold weather slows the self-discharge rate and as long as they are fully charged with enough water, they won't freeze.

From US battery: "A fully charged battery has a freezing point around -80 °F while a discharged battery has a freezing point around 20 °F. By keeping the battery fully charged during the winter months, the electrolyte is less likely to freeze and cause unexpected failures. "

Now I've lived in some mighty cold climates in my life, but never where the temperatures dropped below -80 °F. I think the coldest I've ever personally experienced is about -52 °F. Now that's pretty darned cold, but its' still a good ways from the magic number to freeze a fully charged battery... So unless you are wintering over in, say Antarctica in the mountains, I think you can safely leave your batteries in the boat, especially if you have a way to keep them charged - or as @dlochner says above - disconnected.

dj

 

[Claude L.-Auger]

Not to hijack this thread about water freezing in bilge, but reading Maine Sail excellent report on batteries might help those who still remove and bring the batteries homes.As for me, I'm too old to do that. I've got enough other chores to take care of when winterizing. Make sure they're fully charged and disconnect. See Effect of Winter On Self Discharge

 

[Capt Robbie]

doubtful that the float switch can be damaged, however the pump impeller can be damaged or the pump its self could over heat and burn up. Batery can be drained if float switch gets stuck in on position.
Mine burned out many years ago due to frozen pump. Sence then I dry out bilge and add antifreeze thru it untill I see it run out the discharge.

One guy in the marina puts three pounds of rock salt in socks into the bilge then removes them in the spring. He said that the rock salt slowly desolves in the bilge water and keeps the bilge clear of ice. He is I fishermen and goes fishing a lot durning the winter. He has been doing this for many years with no issues.

 

[Scott T-Bird]

I just purchased the boat, and it's still at the dealer till the spring. It's on the hard. The batteries are connected, as the dealer says they'll periodically run AC power to charge them over the winter. They also say "they're responsible" for it over the winter. But when I visited it last weekend, I found water in the bilge. Yes, they're "responsible", but you know how that goes. My boat, my future problem. I'll be visiting it periodically, and will empty the bilge as often as I can. It's not plastic-wrapped, but it shouldn't add too much water (I hope). Yet, there is some there now, and it was there over recent below freezing days. Thus my question. Thanks to all for your answers, and to any other thoughts you may have!

Interesting development! Leaving the batteries connected for charging is one thing (a good thing), I would also suggest that the bilge pump should not be operational. If I'm not mistaken on my Catalina 320, the auto-bilge can be disabled simply at the switch. You might want to look into that because I agree that it should not be left to chance that it may turn on at a bad time. I'm surprised that you find some water in the bilge. Is there any explanation from the dealer? Is it a very small amount possibly from condensation or a greater volume, say from a possible leak? With a new boat that you just purchased, I'd look for explanation for that. Also, what do they say about adding antifreeze to the bilge? I've had it added to mine by the yard on occasion and I never liked it … it left a sticky mess. Personally, I'd rather deal with a small amount of ice and I've never had a problem with the bilge pump parts. But I would be very curious about what a dealer has to say about adding anti-freeze to the bilge, or if there is reason not to. I like the rock salt idea and I think it won't hurt at all to give that a try!

 

[MikeHoncho]

If your float switch blows apart from frozen water in it, you didn’t want to continue use it it anyway.

 

[Dalliance]

My boat is always shrink wrapped for the winter months, but I do sometimes get condensation in the bilge and I hate seeing my bilge pump and float switch sitting in a block of ice. I believe it is possible that ice could damage to them, so I always put some antifreeze in the bilge. Cheep insurance in my opinion.
The batteries are completely disconnected after being fully charged and they stay on the boat for the winter.