bilge heaters vs. block heaters

[holtcl]

Question: A couple years ago I had block heaters installed (the kind that probe into the engine) and really only have used them to "pre-heat" the boat for cold starts in cold weather.

I'm trying to plan for this winter season and wondering if folks run block heaters "continually" (mine do not have thermostats) to keep engine rooms and their associated equipment from freezing. OR is it better to get one of those "boatsafe"- type heaters?

I was amazed at how warm it was in the ERs after running the block heaters in the cold weather last year. But I hadn't thought about running them in a continuous fashion, due to potential for engine damage (?).

I don't care to actually winterize.

Cheryl
Cinderella
1971 53 MY

[Dan Mapes]

When we had our engines surveyed, they recommended Tstats on the block heaters. We have yet to put them in but having moved to SWFl we have no need for them any more.
If you are up on the hard, I would challenge heating them at all. But in the water I would say sure since you probably have adequate power available until there is a power outage.
Depending on your location Winterizing is cheap insurance.

[SeaEric]

I winterize my engines around the first of December each year. I have fitted, insulated covers with rubber gaskets that snap tightly on the ER vents on the hulls sides to keep the wind out. I have 250 watt Wolverine oil pan pad heaters, one on each engine that I leave on 24/7/365. Even on the coldest day with the marina basin frozen over I never saw less than 40 degrees on the engineroom thermometer.

[davidwigler]

I still have a pair of the thermostats, never installed, going cheap.

http://www.samsmarine.com/forums/sho...tats-1-2-Price

[jim rosenthal]

I leave the oil pan heaters on all winter long. They are on now, as a matter of fact. I also winterize the engines, the generator set, the fresh water system, the AC systems, the head, and the bilge pumps. Of course, she is out of the water all winter, beginning November. And under her winter cover as well.

I think you are making a mistake by not winterizing, since you brought it up. You have the risk of the engines being damaged from freezing, if the power goes off. Flushing the seawater side of the heat exchangers, pumps, etc, is not difficult- and then the engines sit with clean antifreeze in that circuit all winter long. Instead of Bay water etc. If you have the misfortune to have a hard freeze and the power off at the same time, the damage to your boat could be catastrophic. It could also sink you. I would not take that chance.

I installed winterizing Tees in the incoming sea water lines years ago. I shut the sea cock off, unscrew the plug in the winterizing Tee, screw in the adapter and hose, and put it into a bucket. I have a fresh water hose in the bucket and I usually run 3-4 bucketfuls of fresh water through each engine. Even at idle, the engines empty a bucket in about twenty seconds. Then I put in five gallons of pink antifreeze and run until the bucket is empty. By that time it's coming out the tailpipe. Any water that's gotten into the mufflers and tailpipes runs out when she's lifted for haulout. I grease the plug, with trailer wheel bearing grease, and screw it back in. Once she's out of the water, I open all the sea cocks so that they are free of water that might freeze in them and burst them during a hard freeze.

I realize you are on your boat all the time, but it's worth it to think about situations where you might NOT be on your boat, and she might be at the mercy of cold weather AND a power outage in the bargain. That would be a bad combination, and one we've seen fairly often around here.

As far as the block heaters go, you could put them on timers or thermostats without difficulty. But I still think you should winterize your engines.

[MikeP]

FWIW - If they are in-block heaters, they are likely at least 1000W heaters. The ones in our engines are 1500W each. So that's a LOT of power to be using. Obviously, T stats will reduce the 24 hour power draw but it's still going to be a good bit of power, in our case, around 25 A whenever they are on. If you are on the boat, there is a fair chance that you could trip a 50A breaker quite easily just doing normal stuff on the boat, especially when you consider that you will probably be using some sort of electrically-powered space heaters. Also, consider that the water heater will be cycling periodically - probably another 1500+ watts. Then there's the microwave/stove... I see a lot of breaker-tripping!

However, you are fairly close to the head of the dock so it's not a long walk to reset the breaker!

IMO, in-block heaters (unless they are very low power) are not suitable for what you are wanting to do simply because of the practical side of supplying power to them WHILE you also have to power the devices needed to support "daily life" with a 50A service.

[davidwigler]

Mine are 1000 watts each and I never tripped a breaker. I plug them into a digital wall thermostat that maintains the engine rooms at 50°. The blocks stay at 70 to 80 and the heaters come on intermittently. There is no condensation.

[jim rosenthal]

And if you are NOT a liveaboard, then not winterizing your boat is insane, plain and simple. No offense to present company but you have GOT to winterize her. We have had some serious weather around here in the last few years and much of it has coincided with conditions in which you really would not want to be driving around, or walking on icy docks.

[krush]

Who pays for the electricity? 1kw to 3kw continuous adds up over time.

[davidwigler]

I like to run the boat all year. I live aboard so that helps.

The block heaters are much more efficient than the forced air wall heaters. It gets down to 0 degrees here but the water temp stays above freezing.

I've been unwilling to trust winterizing a vessel that stays in the water. What if a seacock freezes?

With the blocks at 80 degrees it would probably take 24 hours for the ERs to reach freezing in a power failure. Time to exercise the generator anyway.

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