Community Forums

Cat · 12-23-2014, 05:04 PM

I'm going to include a wiring drawing from C7, 3126B 3126E. As you can see it is run through a relay and is fused for 100AMPS and 130at 11 volts Dc. So normal amperage should be the 70-90 amp.

Cat320 · 12-23-2014, 06:55 PM

Quote:

Originally Posted by mchero

Block heater is 120VAC
Need to be plugged in OR fire up the genset. If the temps are around 32 deg. a couple to three hours, any colder leave on overnight.

My coach also has an Aqua Hot that has a preheat feature if AC power is not available.

Thanks to all who replied.

mchero · 12-24-2014, 05:23 AM

When we hit the road e plan on heading south to warmer climate!!
LOL

PatStab · 12-24-2014, 07:44 PM

I have a 92 Eagle, it has the cord for the block heater but I've never used it. It cranks right up and starts down toward 20 and doesn't smoke, but its also in a garage. Since I never had an issue never tried it, I may do it. Would it be easier on the engine if I did? Since I've never used it don't even know if the block heater works. It has a receptacle in the electric compartment for it but think I will just plug it into the receptacle where I keep it plugged in to keep the battery minder on instead for a few hours and see what happens.

mchero · 12-24-2014, 08:24 PM

Quote:

Originally Posted by PatStab

I have a 92 Eagle, it has the cord for the block heater but I've never used it. It cranks right up and starts down toward 20 and doesn't smoke, but its also in a garage. Since I never had an issue never tried it, I may do it. Would it be easier on the engine if I did? Since I've never used it don't even know if the block heater works. It has a receptacle in the electric compartment for it but think I will just plug it into the receptacle where I keep it plugged in to keep the battery minder on instead for a few hours and see what happens.

Locate the block heater on your engine and CAREFULLY check the cord back to the receptacle in the electrical compartment.

My block heater is connected to a lighted rocker type wall switch. Light turns on when you flip it on. Don't think it's working if that light goes on!

I thought my block heater was functional till I found the cable to the block heater frayed on the hot side of the cord!

The cord is also grounded to the block heater as well (three leads, hot/common/ground. My block heater cord has a female plug on the end that plugs into the block heater.

Much easier on the engine when you have the block heater on. I have started my CAT c7 in as low as 28 deg w/o a block heater. About a 5 to 6 seconds longer on the cranking but she will start. High idle kicks in when she smooth's out after about a minute. Have to wait 30 to 45 seconds, sometimes longer on the preheat.

My 93 Pace Arrow has the 8.3l Cummins. I have cranked her up in 10 to 20 deg. weather with no block heater. You have to floor the pedal while cranking then she will kick off & then smooth out. I love that 8.3, she fires off 1st crank!

gbburgess · 12-24-2014, 09:15 PM

I have a Cummins ISL 400 with HydroHot and a engine preheat. I keep the RV in a commercial garage and only have access to 20 amp, 120 volt electrical. I cannot leave it plugged in all the time. How long do you think I should leave it plugged in to get the engine preheat to warm the engine. I assume the HydroHot also would try to heat the coach at the same time. Any suggestion would help given we will have daytime highs in the low 20's when we get ready to head out.

mchero · 12-24-2014, 09:41 PM

If it's down to 20 I'd put in on the block heater the night before. I know nothing on the hydrohot.

Cat320 · 12-25-2014, 05:59 PM

Quote:

Originally Posted by gbburgess

I have a Cummins ISL 400 with HydroHot and a engine preheat. I keep the RV in a commercial garage and only have access to 20 amp, 120 volt electrical. I cannot leave it plugged in all the time. How long do you think I should leave it plugged in to get the engine preheat to warm the engine. I assume the HydroHot also would try to heat the coach at the same time. Any suggestion would help given we will have daytime highs in the low 20's when we get ready to head out.

My Aqua Hot has three switch positions: Water Heat, Coach Heat, and Eng Pre Heat. If you want the coach heated you must turn on the "Coach Heat" switch, the Eng Pre heat will heat the engine coolant only. I also have AC power where my coach is stored, and I turn on the AC Eng Pre Heat (not the Aqua Hot) switch and plug in the cord attached to a timer. I time it so the eng pre heat comes on about four to five hours prior to departure.

gbburgess · 12-25-2014, 06:54 PM

If I understand you correctly I need to turn on the HydroHot electric switch (not the diesel heat switch) and the engine preheat switch. I assume that I need to set the coach thermostat for some temperature (45 degrees or less) so the Hydrohot electric heating elements will come on. At this point the pumps for the interior heating and the engine preheat begin working. I assume the 1650 watt heating element will take forever to heat the interior and the engine block. How long do you think it will take to heat the diesel to make starting easier?
Thanks

Steve Ownby · 12-25-2014, 07:49 PM

Quote:

Originally Posted by gbburgess

If I understand you correctly I need to turn on the HydroHot electric switch (not the diesel heat switch) and the engine preheat switch. I assume that I need to set the coach thermostat for some temperature (45 degrees or less) so the Hydrohot electric heating elements will come on. At this point the pumps for the interior heating and the engine preheat begin working. I assume the 1650 watt heating element will take forever to heat the interior and the engine block. How long do you think it will take to heat the diesel to make starting easier?
Thanks

You have something of a misconception of the HH operation. All HH functions are accomplished by a reservoir of coolant which is kept up to temperature by either an electric element or a diesel burner. The diesel burner is high BTU and will bring the coolant up to temp in short order. The electric element is really to keep the temp up after the diesel burner has done the heavy lifting. This reservoir is pretty well insulated and to operate efficiently the temp should be maintained by one or the other of the heat sources. I leave both my diesel and electric switches on 24/7 and have for the 8 years I have lived full time in my coach.

The fresh water is heated by running through a fresh water copper loop inside the hot coolant reservoir. There is also an engine coolant loop that is heated by the HH coolant. The engine preheat switch turns on a circulation pump that controls the coolant circulating to the engine. The thermostat controlling the furnace function turns on circulation pumps to the various heat zones in the coach. All of these functions are accomplished by utilizing the heat stored in the coolant reservoir in the HH.

The HH has the smaller reservoir at about 6 gal of coolant. The AquaHot has a reservoir of about 16 gal of coolant. Because of this smaller reservoir, the HH prioritizes the hot water function. If you are taking a long shower the furnace function will shut off until the hot water demand is over.

Steve Ownby
Full time since '07

gbburgess · 12-26-2014, 05:42 AM

I agree with your analysis. The RV is stored inside a building and I cannot turn on the diesel AquaHot portion while inside due to the fumes emitted. Therefore, I either attempt to start the diesel engine normally or see if the AquaHot system, on electric only, will warm the engine block enough to make starting easier. What I do not know is if this can or will work and if it does work how long would it take using only the electric (a 20 amp 120 volt service) portion of the AquaHot system. This is the first time I have dealt with a diesel and am still learning. Thanks for your help!

Steve Ownby · 12-26-2014, 05:50 AM

Quote:

Originally Posted by gbburgess

I agree with your analysis. The RV is stored inside a building and I cannot turn on the diesel AquaHot portion while inside due to the fumes emitted. Therefore, I either attempt to start the diesel engine normally or see if the AquaHot system, on electric only, will warm the engine block enough to make starting easier. What I do not know is if this can or will work and if it does work how long would it take using only the electric (a 20 amp 120 volt service) portion of the AquaHot system. This is the first time I have dealt with a diesel and am still learning. Thanks for your help!

Do you have a separate engine block heater element? If you do and you are not using the other functions of the HH and the systems in your coach are winterized and you are not in danger of the fresh water loop freezing, then I would use your limited electric on the block heater. You will be applying more of your available power toward heating the engine.

Steve Ownby
Full time since '07

mchero · 12-26-2014, 07:49 AM

Thanks for the pictures CAT.

gbburgess · 12-26-2014, 08:39 AM

The RV does not have a block heater so all I have is the HydroHot and whatever I can do with the engine preheat. I have completely winterized the HydroHot water system with pink antifreeze. I guess I will just turn on the HydroHot a couple of days before we want to leave and take whatever I get. Heating the pink antifreeze should not hurt it or the system any and I will drain it as soon as I hit Oklahoma. I guess something is better than nothing. I hope it warms up a bit in the next couple of weeks. Thanks