Skip to main content ↑ ↓
Topic: Block heater question (Read 2076 times) previous topic - next topic

Block heater question

We're currently in St. Peters, MO and if you have been following the national news you know that most people are predicting major riots in the area when the Grand Jury releases their conclusions on the death of Michael Brown. Ferguson, MO is about 15 miles or so east of here. Temperatures are mostly going to be under 50 degrees. Will it hurt anything to leave the block heater on all the time?

Lest anyone worry, we DO NOT expect any rioting here, but we're also not going to wait until the rioters are right outside the door. We're monitoring local news and do have a plan to go elsewhere should it become necessary.

Re: Block heater question

Reply #1 –
I don't think it will be a major issue to leave the block heater on as long as the temperatures stay cold. We've left the block heater on for a month at a time with temps down in the single digits night and teens day and it seems to be just as good as it ever was. I started the rig up and drove it 25 miles this last Wednesday. Had the block heater on overnight.

We leave the block heater on our Dodge pickup with a Cummins diesel just like our RV all winter and have sincd 1994. But we use that more often in the winter.

Craig

Re: Block heater question

Reply #2 –
We would leave block heaters on constantly on plow trucks stored outside.  The only heaters you have to worry about are the ones that heat the oil.  Yours heats the coolant.

Keith

Re: Block heater question

Reply #3 –
Thanks. That's pretty much what I expected, but I thought I'd better ask those who know a lot more than me.

Re: Block heater question

Reply #4 –
Just be aware you're going to use a LOT of electricity.  I forgot I'd left mine on for two weeks and almost had a heart attack when I got my bill.  If you're in a campground then it's only an ethical issue.  I'd offer to pay.

Re: Block heater question

Reply #5 –
Why do you have to worry about heaters that heat the oil? Do the heaters get the oil hotter than the engine does?

Re: Block heater question

Reply #6 –
David,  if you want the engine to be warm for starting then 24-48 hours on the block heater should be sufficient especially at 50°.  48 hrs last winter here at -18 and it started right up.

A 2000 watt heater would cost 25¢ an hour to run, probably more in most places. $6/day adds up in a hurry.  They are probably not on all the time.

Roger

Re: Block heater question

Reply #7 –
If I remember correctly (NOT a safe assumption), I have a 1000W heater. Current temp is 54, so I'm guessing that the heater probably isn't running much. Temperatures are going to be all over the place for the next few days, so I'm going to leave the block heater on. No word on when the Grand Jury will release their findings, so things are still pretty peaceful here.

Re: Block heater question

Reply #8 –
I would have the heater on when ever the temp is below about 40 deg.  That engine should start anytime above that.  I've started our Cat at temps well below that.  Your call, whatever makes you feel safe and ready.  ---- Have a great day  ----  Fritz

Re: Block heater question

Reply #9 –
My 6V92TA with straight 40 weight oil in it will start on one battery down to at least 42 degrees. It'll start with all three batteries when it's a lot colder than that. It's a rough start with a lot of white "smoke" unburned diesel vapors and rough running and of course it's very loud for a bit until the computer senses the engine has all cylinders firing, then it smooths out and sounds almost normal. I'm sure it's not good for the engine to start it up cold with thick oil but if ya gotta, ya gotta.

I'm still curious why you have to be careful with oil heaters. Can they heat the oil hotter than the engine does? I'm planning to install a plug type heater in the oil pan drain on my next oil change. I was considering getting the most powerful plug heater but now I'm curious and considering possibly buying the least powerful plug heater if overheating the oil is a possibility. Is there any evidence of this? The most powerful oil plug heater I've found is 300 watt.

Re: Block heater question

Reply #10 –
Concern re oil heaters is possibility of condensation inside engine, with possible corrosion, if left oh continuously. Pad based pan heaters in general preferred over stick heaters, but of course more $$$

Re: Block heater question

Reply #11 –
Quote from: kb0zke –
... I have a 1000W heater. Current temp is 54, so I'm guessing that the heater probably isn't running much...
I've never heard of a thermostat controlled block heater on a Foretravel.  I know mine runs continuously when turned on.

Re: Block heater question

Reply #12 –
Happy to see this discussion. I found the outlet under the foot of the bed, the plug (not plugged in) and the switch for the outlet (with red light) about 3 years ago! ;D
I figured it was for a block heater, but never bothered to test it to see if it works. Today I Plugged it in through a Kill-A-Watt meter and found it draws 11 + Amps and uses about 1,390 Watts. Will start using it; and could have the past few days in Oregon.
Dick

Re: Block heater question

Reply #13 –
This is correct for the block heater on our coach as well. The cord is just a cord with with a grounded A/C outlet plug on one end and a threaded coupler on the engine end. The heater itself is just a simple resistance loop like the electric element on our house water heater. When we got the coach, the cable was unplugged under the bed and at the engine. Both the engine and coach ends were somewhat melted, though the engine end was so far gone that it was just a lump of stuff. I had a hard time finding the heater location on the block... I theorized at the time that the block heater must have shorted out and caused the meltdown. The A/C outlet under the bed appeared to be undamaged. I bought a new block heater and cord from Cummins... When I had the baseline service done on our coach up in Colton CA (all fluids and filters changed and a couple of misc items), I discovered to my chagrin that neither the new block heater or cord was with us >:D >:D Anyway, after we got back from Texas, I cleaned the melted gunk out of the terminals at the block heater end and plugged in the new cord and was surprised and happy to find the the block heater got hot, but cord stayed relatively cool. Moral of the story, I am reluctant to just turn it on and leave it on unless the temperatures are nearing freezing and staying there. There ways of safeguarding the system though...
this site has thermocubes (discussed elsewhere on the forum), heavy duty digital timers, block heaters, oil pan heaters (including a couple of interesting magnetic models (that only work on steel oil pans, of course).
Auto Air Conditioning Parts & Heaters by Auto Cooling Solutions
Don
Quote from: JohnFitz –
I've never heard of a thermostat controlled block heater on a Foretravel.  I know mine runs continuously when turned on.

Re: Block heater question

Reply #14 –
I turned the block heater off for now, but I'll turn it back on again before we head for bed. Supposed to be near 60 tomorrow, but then the highest temperature predicted is 43.

Re: Block heater question

Reply #15 –
In the 40-60 degrees F range, an hour or two is PLENTY of block heater time.

Re: Block heater question

Reply #16 –
David,

If your Detroit has the block heater up high on the thermostat housing, it will take 3X longer than the Cummins block heater. If fact, the Detroit thermostat housing location means it's not a real block heater. Some Detroits have the heater under the AC  compressor to block mounting plate low on the right side of the block. They work well.

Pierce

Re: Block heater question

Reply #17 –
Pierce, I think mine is the same as yours, about eye level on the left side as I face the engine from behind the coach.

Re: Block heater question

Reply #18 –
David,

Yes, that is the thermostat housing location for the heater.

If it's working, after about ten minutes, the crossover pipe should be quite warm to the touch. If not, check the outlet where it plugs into up high forward in the engine compartment. Pull the plug out and check for overheating. Mine failed at the connection at the block heater and the supply voltage fitting. It corroded and then overheated.

New block heaters share the same part number as the straight element CAT heaters and are available in several different wattages. Also, they are of slightly different construction so should be less prone to corrosion. I chose 1000 watts for ours. They come complete with new wires. Changing on a cold engine will minimize coolant loss.

Remember to switch heater off before cranking. At 50 degrees, one hour, 40 degrees, 2 hours at lower elevations, longer if higher. Our engines don't heat intake air like some others.

Found a NOS on eBay for under $40 delivered. Thermostat location heater is different and not interchangeable with AC compressor location.

Pierce

Re: Block heater question

Reply #19 –
How do you know that the two cycle Detroit Diesel doesn't have an intake heater? I was attempting to verify that but I can't find any statements supporting that conclusion from Detroit Diesel or anywhere else. Why does my voltmeter go way down when I turn on my ignition key and the red lights on the dashboard come on for a few seconds if there's no intake heater or glow plugs? Also, when I attempt to start the engine before the red lights go out it just cranks and cranks but doesn't actually start until after the red lights go out. It sure seems like it's waiting for something to heat up before it can start.