How long does an engine coolant heater need to be plugged in?

[Bill_B]

I had one of the engine heaters that gets cut into the radiator hose. I would plug it in and hour or two before I wanted to start the tractor and it didn't seem to help at all. Did I need to leave it plugged in longer? Like over night? Was it a junk heater? Do they not really work below O degrees? Should I have had a battery heater?

 

[Cycledude]

Depends a lot on how cold it is, 1 hour helps a lot but when it’s much below zero I prefer to have mine plugged in for a few hours or more.
I also have experience with some tractors over 100 horsepower sitting outside when it was 10 below zero not plugged in and they start instantly and don’t even smoke.
I dont like hose heaters, I highly prefer block heaters

 

[jaxs]

Variables such as ambient temperature and shelter make a lot of difference in required time. Heater in lower hose only works when there isn't a t-stat at upper hose blocking circulation. Water warms as it expands pushing colder coolant in engine out to be replaced by warmer coolant. Not the best system but better than nothing. 2 hours isn't long enough for most heaters. Timer coming on hours in advance helps for early am start ups.

 

[Deere Dude]

It may not even work. I had a GMC diesel that I plugged in at work during some cold Wisconsin cold snaps and the truck started hard quit often but always started anyway. After quit a few years I sold the truck and bought a 2002 GMC diesel and did the same thing only at home. After a couple hours plugged in, the water was warm enough to start running the heater right away. The take away from that is, my original heater either had a blown fuse or broken wire or something else, I never found out. That was my first heater and thought it was working but it actually wasn't.

My JD tractor only needs to be plugged in an hour or so and will start very well in the coldest weather around here. Most of the time I never plug it in because I just don't go out in the cold, but I could.

 

[RjCorazza]

The block heaters I have used had a sweet spot of 3 hours on time to raise the block temp to around 40 degrees f over ambient.
Less time and the block was not uniformly warm, more time didn't raise the temp any more.

 

[oldnslo]

We always plugged ours in the night before I plan using them. The wattage they use isn’t even noticeable on the electric bill and figured that little bit of electricity won’t buy many parts.

 

[BlueKnife]

I had one of the engine heaters that gets cut into the radiator hose. I would plug it in and hour or two before I wanted to start the tractor and it didn't seem to help at all. Did I need to leave it plugged in longer? Like over night? Was a junk heater? Do they not really work below O degrees? Should I have had a battery heater?

It depends. Colder temps and/or wind require more heating time. Also, generally speaking, the lower in the system the heater is, the quicker it will work (heat rises). If it's in a hose at the top of the engine, it's gonna take a lot longer.

 

[CalG]

My tractor with a Mitsubish 4L 1.5 liter engine needs over an hour to start well in 20 degree F weather. About half that at 30 degrees.

Below zero? Why? ;-)

 

[mrmikey]

I have a 400W inline heater in my Iseki 3160, reason I used an inline is there's no place to mount a block heater, least none I could find. I plug it in at least two hours before I'm going to use it, three is even better.

 

[mikester]

If you clean snow at 6am set the timer to start at midnight. If it's colder out start earlier