What is your Block Heater Temp setting???

120 degree in the ER set off alarms for us. Why would you want it so hot? 70-80 degrees should be plenty hot. Maybe even 60.

Which “engine folks”said you need the heaters on all the time? There have been a number of debates on the subject here. I just can’t understand why they need to be on all the time?

Can you link any MAN sheet specifying a requirement to use block heaters - let alone keeping them on 24/7?
In all their engines (yours 1550 included), heaters are not even included as standard, and are available as an option only if specifically requested by the boatbuilder.

I'm as curious as Dockmaster to know who these "engine folks" are, exactly.

Thanks God this ain't twitter.
I agree it's not your job to convince me of anything, but neither it is to post ironic replies and wrong statements, pretending they are supported by the engine manufacturers, when in reality they are not.

My Cat tech said leave the block heaters on all year as well. Keeps moisture out of the combustion chambers. I complained about the engines being too hot to touch at black heater temp. He changed from 110 to 240 units wired to my 110. Then the engines stayed warm not hot.

In my opinion, the temp need only be above the dew point[/QUOTE]

I would tend to agree with you as far as temp goes if you are planning to keep them on. I can’t see any value of keeping them that at a temp above dew point while not in use. The heaters in my new C-18’s will bring the the coolant temp up to 110-120 degrees F when I turn them on about 24 hours before firing up.

Maybe add a second heater that you can select and use at a lower temp for storage then turn the other one on 24 hrs before firing up to bring them up to a warmer temp?

I would tend to agree with you as far as temp goes if you are planning to keep them on. I can’t see any value of keeping them that at a temp above dew point while not in use. The heaters in my new C-18’s will bring the the coolant temp up to 110-120 degrees F when I turn them on about 24 hours before firing up.

Maybe add a second heater that you can select and use at a lower temp for storage then turn the other one on 24 hrs before firing up to bring them up to a warmer temp?[/QUOTE]

Well, it's both dew point and also location/weather. When the water is 70+ degrees, the block heaters really only provide a benefit prior to start. But certainly you're doing no one any favors except the technician and parts department together with the utility company by holding them at 120.

Another alternative is to add a simple heater to the ER to lessen the wear and tear on the block heaters. Then just flip them on prior to start.

All the block heaters I have used are on when ever they have power. In below freezing temps, I use Thermo Cubes to turn them on and off.
The cubes I use turn on at 35° F and off at 45°. They're available in other temp ranges, like needed for air conditioners. The cubes are on ebay and Amazon and cost about $15-20 and rated at 1500 watts.