It Finally Happened

[MaverickBBD]

I was leaving a club outing on Sunday morning. The temperature got pretty chilly over night so I thought I would give my engine some pre-heat before attempting to start. I flipped the switch, hung the 'flags' on the switch and the cabinet in front of the driver's seat. After an hour or so started the engine. Saw the engine temp was 59 degrees upon starting. Took the reminders down and drove home. Put the motor home in the shop leveled it put the slides out and plugged it in. Yesterday (Tuesday) DW says she smells something funny like burning electrical in the shop. After 27 years working in an oil refinery I can't smell anything. Round up and check the usual suspects. Then just when I was ready to give up I checked inside the motor home and the pre-heat switch was still on. Engine temp. was a toasty 119 degrees. I hope I didn't burn it up. Will check it today. That is what I get for leaving it plugged in inside the compartment outlet.

[wagonmaster2]

I had read a warning before about being careful to turn off the engine heater immediately before/after starting the engine, but that was because if you dry camped using the invertor your coach batteries wouldn't last very long.

You've posted a good warning, and I'd be surprised if you ruined anything since as I understand the heater is just a water (or oil) heater for your engine. Kind of like the electric water heater element which some RVers say they leave on all the time they are out in it.

[MaverickBBD]

I agree I don't think I did any permanent damage except maybe burn up the heater. I will wait until the next time I use it to see if it does anything. I am not sure that circuit is supplied by the inverter so I might have been safe there. Good thing I didn't have to test it by trial and error.

[powerboatr]

the block heater has a thermostat, it will shut off once it reaches the temp its set at.
then cycle as the block cools,

the power consumption is high......
if it does run off your inverters, then the batteries will be dead in short order and the heater will be off......
my coach the switch is in the back of the rig, and no indicator on the dash....i need to put one up there, because last winter i left mine on for quite sometime before i remembered it

[DriVer]

I did not expect that there would be long term problems if one ran their block heater for extended periods of time since a lot of folks run over night or over the weekend. If the heater was drawing from the inverter, the heater would pull the batteries down pretty quickly. A block heater consumes about 1000 watts. Plugged in it could keep going like an Energizer Bunny.

[target]

Part of my job is to maintain backup generators for our 5 radio towers. These are just 4 cylinder John Deere diesel engines but have to start at a moments notice. The block heaters are left on 24/7, but the county picks up the tab