Block heater - Leaving them on- in storage

[newinlet]

My 37 is stored indoors in Ma. I had the bilges painted last week. to keep the boat warm I blocked off the air intakes and put on the block heaters, these are the type that an element goes into the side of the block and warms the coolant and there are no thermostats.
I checked on the paint job today and it is sweet. My question is the boat was so dry and warm I did not want to shut the heaters down.
Is there any downside to leaving the block heaters on while in storage? I assume as long as the coolant is full and the power to the boat is correct all should be well. anybody ever do this on the hard ? any issues ?
A few years back an old timer said leaving the block heaters on caused problems with the oil or cylinders or something like that . Any input would be appreciated.
Thanks ....

 

[34Hatt]

I have left my wolverine oil pan heaters on for the winter before. It does keep engine room nice warm and dry. It keeps the pan about 110 degrees so no problem with that. What temp are your block heaters at??
Also you can put a Thermostat in line also.

 

[Brian Degulis]

On many comercial boats with large engines it'a SOP to leave the block heaters on whenever the engine is shut down even in the summer. This eliminates condensation and minimizes expansion and contraction which results in longer oil change intervals, less oil leaks and longer engine life. The only down side I see is the electric bill.

Brian

 

[Silverado6x6]

Condensation in oil creates acids, in Alaska we find its better to keep a maintained heat level to prolong oil life.

 

[REBrueckner]

"Condensation in oil creates acids, in Alaska we find its better to keep a maintained heat level to prolong oil life."

This is why it is always recommended to change oil at the end of the operational season.

 

[hattitude]

I leave mine on 24/7, keeps the engine room nice & dry..

I have 8V71TI's with 1000 watt(per engine) Kim Hotstart heaters that have thermostats. The heaters kick on below 100 degrees and off at 120 degrees. Not sure how hot they would get without thermostats though.......

 

[spartonboat1]

I have left my wolverine oil pan heaters on for the winter before. It does keep engine room nice warm and dry. It keeps the pan about 110 degrees so no problem with that. What temp are your block heaters at??
Also you can put a Thermostat in line also.

Thermostats are definately indicated. I (or a tech?) left mine on once for a week, no thermostat and it got hot enough to bleed off some coolant.

 

[krush]

Electric bill sucks, as mentioned.

Useless info, almost every electric motor in/around a power plant has a small space heater in it for when it isn't running to minimize condensation around the rotor. I often think it's overkill though, especially if it is VERY cold out (and thus very dry).

 

[Brian Degulis]

That's very common on the old Diesel/Electric tugs especially the DC units. The strip heaters are always on when they sit because condensation causes all kinds of problems.

Brian

 

[MikeP]

I've heard all my life about how condensation causes problems but I've never seen any evidence of it and I've torn down engines that weren't run for several years in vehicles that sat outside in the northeast and in Alaska. Never saw any problems that one would expect to be caused by moisture/condensation.

No pitted bearings, etc. Years ago I came to the conclusion that the primary reason people change oil for storage purposes is because the OIL distributers sell more oil if you do that; just as Jiffy lube wants you to change oil in your car every 3000 miles...absurd, unnecessary, and a waste of money.

I quit changing the oil in vehicles for winter storage some time ago. I run them up to operating temp before storage and that's it. I don't run block heaters for storage for the same reason...IMHO it's a waste of money and no benefit OTHER than keeping the eng room warm while doing work in the winter.

 

[krush]

I'd say it depends on weather, humidity, and operations. If the motor is going to sit all winter and is fogged down---I see no real reason to waste the power.

If the motor is used each day and shut down each night, there MAY be a benefit to leaving it plugged in.

 

[Akyla]

I found that leaving my engines heated with the Wolverine pan heaters kept the condensation off the machinery resulting in minimizing the rust on the components. We have big swings in temps and humidity in the winter and before the engine blocks would get cold then the warm damp air off the Gulf Stream comes in and everything would sweat condensation and then start to get rusty. After installing the pan heaters and letting them run no more condensation and rust forming a thing of the past.

 

[hatteras4164]

Always keep warm if you can