Have a question about APUs or Truck Generators? This is the place to get your question answered,

Incoming search terms:

21 Customer Reviews of “APU FAQs”

Review by Pete 379, July 22, 2010

I see wildy different BTU’s when I am looking at different APUs and Generator systems how come? Does it really matter?

Review by admin, July 22, 2010

@ Pete

Good question. What this really boils down to is the components being used for the air conditioning and heating. For example a system that uses an electrical heat strip type system for heating will typically be limited to 10,000 BTU (which stands for British Thermal Unit). Some of the more powerful Air Conditioning systems out there like Comfort Master and Blackrock are pushing 33,000 and 26,000 BTU respectively. This is possible because they are using compressor driven systems and the amount of APUs is limited only by the compressor capacity. The down side is obviously that the bigger compressor is the more horsepower that is needed, this is more than likely why the Comfort Master uses an Isuzu 3 cylinder engine.

Often overlooked is airflow which is measured in CFM or Cubic Feet per Minute. The higher this number is the better. Put simply, this is a measurement of how quickly that hot or cold air is being pushed out into your sleeper. The higher the better.

Review by gene, August 15, 2010

where does it connect to the battery and is it hooked to my trucks battery or does it have its own.Been trying to start it and the battery is dead but my trucks battery has plenty of charge.

Review by admin, August 15, 2010

Hello Gene,

Thanks for the question. To help us understand a little better, what APU are we talking about here? Most APUs connect directly to the trucks battery box. Not only do they receive their battery power from the trucks batteries but they also keep the trucks batteries charged and even conditioned (at least on the better units). What leads you to believe that the APUs batteries are dead? Are you getting a specific message? Is there a sound you are hearing? It could be a starter, a failing ground wire, corrosion at the battery connections. These are all things I would look at for starters. If it is a Comfort Master check the connections to the front alternator. Good Luck!

Review by Jimmy, November 8, 2010

this site is not objective by any means. It doesnt even have tripac in the top 5.

Review by admin, November 8, 2010

Hello Jimmy,

We appreciate your opinion but beg to differ. If we were not objective as you suggested we would simply remove your comment 🙂 The fact of the matter is we have no control over what order APU’s are ranked, you do. The rankings are derived from their “user” reviews. If you have experience with Tri-Pac by all means leave a review.

Review by June Marcum, February 11, 2011

My question is this. What type APU would you recommend for special equipment besides say TV/DVD/Fridge/Phone charger, etc.? This issue was brought about by the use of a CPAP machine to treat sleep apnea that is used every night including while on the road. Usually plugs into a 110 wall outlet at home but is there a unit that addresses this type of issue. Thanks!

Review by admin, April 1, 2011

Hello June,

Sorry for the delayed response. When dealing with medical equipment you should always seek the advice of a licensed, professional electrician and medical professional such as your doctor. Now that we have the liability issue dealt with, everything else is nothing more than my own meandering advice.

If it were my CPAP machine I would want the electrical signal to be as clean and pure as possible. Yes, there is clean power and dirty power. The easiest mental picture I can provide is a heart monitor in a hospital. We have all seen the machine that shows the heart beat in a graph form. Well electricity is very similar and just like the heart we prefer smooth consistent ups and downs (clean power) as opposed to radical spiking ups and downs (dirty power). I am sure I will get at least 100 emails correcting me but roughly that gives you a good idea of the difference.

So how do I get clean power? Well in the mobile environment you are in there are basically two main types of APU’s that provide power, the generator type and the alternator/inverter type. In your case I am going to lean towards the alternator inverter type. But this next part is important, you should absolutely make certain that you are using an expensive “sine wave” inverter with your alternator/inverter setup. Yes, I said expensive. There is a time to cheap out and hope the Chinese crap works but when it comes to your health that’s not the right time. When it comes to inverters you get what you pay for. One brand I am comfortable with recommending is Xantrex.

There are a whole host of other reasons I would recommend the Alternator/Inverter setup for your situation. To make it short, you can be plugged in receiving power regardless of whether the APU is running or not. Most of these types of APUs will automatically start and keep the batteries charged when the voltage drops. This will allow you to get a good nights rest without having to worry about running the APU all night. Great question, hopefully this has helped.


Review by kevind4379@yahoo.com, July 30, 2011

I have 400 lb. boat anchor on the side of my truck the name on it is Comfortmaster. After 223 hrs. it quit suppling power to the cooling fan. Traced it to the computer. Any ideas on where this problem can be fixed? ***Edited – We do not allow personal attacks*** They do not answer phone calls and WEB site is gone. Would like to know which location of fast food resturant where they are now serving fries.

Review by Charles, November 16, 2011

I changed the fuel filters along with the oil and oil felter. Now it will not start how do I prie the fuel system, or could there be another problem I need to look at?

Review by Ricardo C.Lopez, September 10, 2012

I’ve trying to change the existing program on my preowned truck APUbut I’cannot access the required code on the thermostat and I’dont have the owner’s manual can you please help me to find a way to change the code

Review by Matt, November 7, 2012

I am looking for a wiring diagram for my promax apu. If you or someone you know has one please send me an email. mattxti@yahoo.com. Thank you for your help

Review by steve, March 24, 2013

unit has a 5hr run limet how do i change that

Review by jerry, January 5, 2014

I just want it to heat up the motor I doint need it to be ac or heat in the truck I just need on that runs when I park on cold night any company make that

Review by TriPac Dude, August 14, 2014

Come on guys quit spamming this site and get back to talking about APUs. The last ten or so comments are total garbage you can’t understand and have nothing to do with APUs, and I enjoy reading this site, at least until these spam messages keep showing up. Many thanks to the owners of this site if you delete the irrelevant spam and get back to talking APUs!

Review by TriPac Dude, September 5, 2014

Get back to talking APUs please! No more Spanish junk either because most of us don’t understand it!

Review by admin, October 20, 2014

Hello Guys & Gals,

It’s been a while and I apologize. This site costs money to maintain and thus requires I have a real job to support, so that’s where I have been.

The spam has been cleared out and I am looking at a major update that would freshen up the look and feel, clean up and add some pages and more organized Q&A area.

In the mean time, if you guys do have a question please be sure to be specific. That is, if you have a question about your unit PLEASE BE SURE TO TELL US WHAT KIND OF UNIT YOU HAVE. Without telling us what kind of unit you are asking about your question will likely never be answered.

Thanks for your support and keep those wheels turning!

Review by John, April 26, 2015

The original truck APU that started the industry almost 30 years ago (invented by a trucker with truckers in mind) outperforms all other APU’s currently available. With years of feedback and design improvements, today’s Pony Pack not only provides the best driver comfort, it can also provide backup alternator and A/C compressor to the trucks system to keep you moving down the road. Almost all parts are commonly found parts that can be picked up at auto or truck parts stores anywhere. Where other APU suppliers want you to depend on them and their expensive parts to keep you moving, the Pony Pack is designed to minimize your down time.

Review by foxtail, July 26, 2015

i have a carrier apu 6000. ac compresstor is getting hot as fire and trips the braker off. anybody got any ideal my

Review by Laura, October 4, 2015

Got hit and I am no longer driving have the comfort master apu. thinking of going off the utility use apu for energy. People are trying to purchase it from me . Have not decided. These apu cost so much kind of be bad to loss all that money. What kind of price do all of you recomend

Review by Larry Black, February 8, 2017

My controller is reading “Inactive System” No clue what that means. Can you please tell me? I have a Dynasist APU

Write a Review