Why the 2007 42′ Tiffin Allegro Bus has our Dream Specifications, and Newer Ones Don’t

This article covers why we would actually prefer an older bus, 2007, over newer models – say 2010 to 2014. . . and why a step-up of only two years – from 2005 to 2007 – was a good deal for us.

 (Written by the wife, Carolie, with all facts provided by the obliging husband, Steve.) 

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Twins!  Old(but loved) 40′ Tiffin Allegro bus on left.               New 42′ Tiffin Allegro on right.

First of all, going from a 40’ bus with six tires, to a 42’ with eight tires (“tag axle”) gives us a lot more room and more storage. But the bus handles almost identically because the wheel base from center of the front wheel to the center of the duals is only 6” longer.  Neither of us would ever want a 45’ bus, the biggest one made, because they are a challenge to drive, to turn corners, and to find RV parks to accommodate. So many RV parks were built after World War II, when RV’s were 30’ tops.

Replacing a 2005 Allegro Bus with a 2007 does not seem like much of an upgrade. But the 2007 was just new enough to have major upgrades, yet still old enough to have features we wanted that are becoming extinct – such as a queen size bed.  Since about 2010, the king size bed has been a no charge option, and most all buyers are taking it.  As the years go by, it’s getting harder and harder to find a used RV on the lot with a queen bed. The king bed might be fine in your home, especially if you have a big dog in the bed with you. But in an RV, the king leaves absolutely no room left to walk around the bed, and no night stands! How can you live without a nightstand for your Bose radio?

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We prefer a queen bed with two generous nightstands and spacious floor area, and now we have it!  If you factory order a bus, you most certainly can have queen bed. But we cannot afford a custom build, and we don’t think it’s financially smart to drive one off the showroom floor anyway. So when we say “new” we mean “new to us”!!  A new bus like ours would cost over $400,000, but we paid just $159,000 in 2014. What a deal!

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See, this 2010 Winnebago Tour with king bed has no space at all on left and about 8″ on right. Where do you put your book, coffee cup, Bose clock radio? How do you reach the corner to make the bed without kneeling on it?

Second feature disappearing – gas range. The new motor homes lean toward all electric, or the new induction surface. They are dropping the gas refrigerator and gas range. Who wants to cook with induction or electric? Not us! We are gas or nuthin! We have a 10×22” ribbed grill pan that covers two burners and we use it weekly to make divine steaks and tender crisp veggies – indoors with no muss or fuss. Yes, gas ranges are a pain to clean, but its so worth it. And hey- we’re retired now.

Third feature gone – dual gas/electric refrigerator. If you want to really enjoy the RV life, leave the crowds behind and go “dry camping” in the desert or beside the ocean. This means you have no electricity to plug into. Old style RV refrigerators could handle this – running on electric in town, then switching to propane out in the country, “off the grid!” How can you beat that? We refilled our propane tank once a year at most. (RV’s that heat with propane are a major headache in cold weather.) All the new RV’s use large, all-electric household type refrigerators that the uninitiated female RV shopper swoons over. But you might have trouble dry camping with this electricity hog unless you start your generator every morning to recharge your nearly dead household batteries. (It also depends on how much tv/computer and coffeemaker you use.) One workaround is to have solar panels on your roof, but the reality is, the sun does not shine every day.

(Editor’s Note: Whoops! We actually did have to settle for an all-electric refrigerator on our new ’07, but we took it because the seller had upgraded this bus with four 120-watt solar roof panels We should be able to dry camp without over-using the generator.)

Fourth feature – A bus without a dishwasher is becoming very hard to find. We actually prefer to handwash our dishes for two, and we get the bonus of a huge, deep storage area for all our pots and pans, directly under the stove, sooo handy! But darn it – we had to take a dishwasher on our new bus. I now have pans dispersed everywhere – in bedroom closet, under bathroom sink, above sofa, in hallway. Fun!


 Here are the major benefits we enjoy by stepping up from 2005 to 2007 bus:

–Three air conditioning units instead of two. This is a critical benefit. We could barely keep our bus cool in the Oklahoma summer. It can be 100 degrees and humid there for weeks, and it doesn’t cool off at night. Our AC was working nonstop to blow air out of the ceiling vents, and it is so loud you have to holler at your guests, and turn your TV way up.

— 10K Onan generator  vs. 7500. The new one is single speed, more powerful and super quiet instead of noisy. You don’t even know its running.

–3000 watt Xantrex modified sine wave inverter, versus a 2000 watt Xantrex modified sine wave  inverter.

–Bigger house battery bank. The 40′ bus has four six-volt lead acid batteries. The 42′ bus has six six-volt lead acid batteries.

—  Side opening basement doors. This is a biggie for us. To access your bay storage on the 2005 bus, you had to kneel down and crawl underneath a top opening door, which was horizontal to the ground. It could not open any higher because it would hit the open slide above.  It is hard to lift 50 pound tubs when you’re on your knees and can’t get any leverage. The new bus has side opening doors so you can remain standing, no more kneeling on worn out cartilege-free knees. No more bumping your head when you stand up.


New Way!

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Old way!


–A separate washer and dryer. 40’ buses have a single, European-style combo unit, which is small and slow. You can’t put more than one sheet in it at a time, so it takes three separate loads to wash your sheets.

— Longer couch for guests. Two can sleep on our new, jackknife style sofa bed. Before, one sleeper had to lie diagonally to fit.

— Spartan chassis (larger radiator capacity for hill climbing).

— Tag axle (more carrying capacity and better driving in the wind).

.–Three windows in bedroom. Steve has his own window for the first time, and we are enjoying cross ventilation).

–Hydro-Hot (new name, Aqua-Hot) Even tho this feature is included on both our old 40′ and new 42′, I have to mention it because it is so critical we could not live a day without it. Hydro-Hot gives us unlimited hot water on demand for showers, and instant cozy heat when we get up in the morning, from the diesel heater booster. This is all radiator hot water heat that doesn’t dry you out like a gas furnace.


Here are additional upgrades the seller added to this 42′ bus:


  1. — Complete solar setup with four 120W rooftop panels and a 60V controller. This will allow us to watch TV, use our computers, make coffee, and keep the refrigerator running when we are dry camping.
  2. MCD Shades with all-electric remote. This divine upgrade is standard on Tiffins from 2009. It’s truly heavenly to have MCD shades, especially if you’ve lived with the old curtains.
  3. The seller upgraded our new bus to a 3000 watt Magnum pure sine wave hybrid inverter instead of 2000w modified sine wave. We now have more power and cleaner power. It automatically supplements with power from the house battery bank for overload demand, whereas our old bus would just pop a breaker.
  4. The seller upgraded from six lead acid batteries to eight six-volt maintenance free AGM’s. Steve once tried to make me look in a tiny mirror and add water to the old batteries up to a line I couldn’t see at all, without overfilling or splashing acid on my hand. I ended up shaking and crying, “Do it yourself, Steve!”
  5. The seller removed a dreadful large box in the clothes closet that just ruins your ability to hang and store clothes. This box is an electrical cabinet holding two breaker panels and a 12V fuse panel. The box is way bigger than it needs to be anyway. The seller cut a hole in the floor and moved two of the panels into an empty space under the closet floor, adding an access door. Then he relocated the fuse panel onto the far right wall in the closet. What a HUGE improvement this is! Now we have an unobstructed closet like we had in our 2005 bus.
  6. The seller installed See-Level Gauges with read-outs both inside the bus and in the wet bay. The usual factory gauges for black and grey tank levels are notorious failures because their sensors are inside the tanks, collecting muck. They like to read “full” no matter what your true level.  See-Level gauges are outside the tanks and shoot through for accurate readings.
  7. –Two roll out bay drawers instead of one. These are wonderful for accessing your stuff.
  8. — SilverLeaf Engine Management System with read-out on dash. This monitors all engine functions and is programmable to display favorite.
  9. –SWM equipped Winegard satellite (with multiplexed wiring, you can watch two different shows at the same time and record several if you have two DVR’s.)
  10. Bose sound system added to both front and back.
  11. A Kenwood Stereo unit with Garmin GPS was installed in front dash to replace the factory radio/CD player. This thing is amazing! It gives you an IPod input port, wireless telephone, GPS navigation, XM radio as well as AM/FM, and a USB port.
  12. In the wet bay, four heaters have been added to keep our water lines from freezing when we are stuck in snow, as we have often been. Two are pad heaters under the fresh water tank. Two are forced air heaters by the hoses and valves.
  13. Norcold 2.12 cubic foot basement freezer added
  14. The seller hard-plumbed a water line from the city water source into the black tank. so you can flush and clean your black tank with fresh water at the flip of a switch, instead of hooking up a garden hose.
  15. Seller added a fresh water pressure gauge inside the wet bay. This allows you to monitor the city water pressure coming in and to add a regulator if needed.
  16. You must protect all your RV electronics from electrical surges. The standard solution is to buy a $300 surge protector and plug it outside between the power pedestal (“current bush”) and your cord. These hang unprotected in rain and weather, and, sadly, are sometimes stolen. The seller equipped our bus with a Progressive Industries Electrical Management System (EMS) hard wired safely inside the electric bay.
  17. Most RV’s come standard with a whole house water filter, and a second for the refrigerator. This bus has two additional filters. Thus, our kitchen water is double filtered and our refrigerator door ice/water is triple filtered. I cannot tell you how wonderful this is for the clean flavor of the coffee and iced tea we make daily, no matter where we drive to in the country. In our old bus, we went from one crazy water flavor to the next. Sometimes we hauled heavy gallons home. Now we feel so spoiled, and we are drinking a lot more water.
  18. Seller modified the Hydro-Hot system to make it easier to service. My husband worked on the Hydro-Hot in our old bus and had to crawl to the back end of a small bay over three days. He came out bleeding and miserable. On the new bus, the seller moved the vacuum cleaner out of the Hydro-Hot bay, onto the ceiling of the next bay, out of the way. Then he moved a wiring panel on the back wall up, creating a large opening below, directly into the Hydro-Hot. We can’t live a day without the heat and unlimited hot water from our Hydro-Hot, but they do need servicing annually and can wear out. Most commonly, a cracked drain tube (loss of antifreeze) or dead heating element.
  19. The toilet has a maintenance switch that holds the flap open but that switch is impossible to access – it’s up inside the back of the toilet where you can’t get your head to look. Our switch has been moved out within easy reach.
  20. The outside front steps have a switch. If you leave the switch on, the steps will open every time you open the door, and retract every time you close the door. Most people prefer to keep the steps out all the time while parked. Because if you accidentally have the steps in, and then turn the step switch off, you can actually step out of the bus with no step below you and fall! This happened to our guest because we had turned the ignition key on. (Lawsuit?!) There is a light but it is tied to the step switch and only comes on when the steps move in and out. Our steps are always out, and our light has been rewired to come on whenever we open the screen door.  This is a much better, safer scenario for a complex system.


So, in summary, we are very happy with our “new to us” 2007 Tiffin Allegro, 42’. This is only the second RV we have owned, and we fully expect it will be our last one. We are going to live in this “BessyBus 2” from now until the cows come home to roost. Please get in touch if you have any questions at all!

Carol & Steve Dwyer




Nov 17, 2014




Girl-Friendly Explanation of the Aqua-Hot Heating System on your RV Bus

Editor’s Note: I truly don’t want to offend any wives by my title above. It’s meant in gentle humor. There are flocks of tech-savvy females on the RV circuit, but I believe the majority are like me. When I started out in 2008, I was mechanical systems clueless. I didn’t even know what a generator was. I was scared of my thermostat. How-to articles started out so far over my head, they were like foreign languages. So for all of us non-techie babes, I have written this article. 

Well girls, I have to confess I totally didn’t understand the Aqua-Hot heating system on my RV bus. I just flipped it on and wallowed in the nice hot water. But if you really understand how it works, you will be in awe of its beauty and complexity. This system really is a miracle. And it’s not over our heads at all, if you can just get a girl-friendly explanation of it.

All RV’s need heat when it gets cold.

Most RV’s have propane heaters (one in front and one in back.)

This RV has an Aqua-Hot system.

The propane heater is identical to the one in your stick house. It uses propane to keep a tank full of hot water ready at all times. This is a very energy-needy system. In cold weather, your propane tanks can run out of fuel every seven days. It’s a huge hassle to keep refilling these tanks. On a small RV you have to take the tanks out and drive to the store. On a big bus you have to pull up stakes and drive your bus to the store. If you decide to stay in one place all winter, you would definitely want to rent a larger tank and set it up.

The Aqua-Hot system, on the other hand, does not keep a tank of hot water ready. It works on demand, heating water just ahead of you as you are using it. What a great idea!

The Aqua-Hot has three different ways to heat itself up.

It can use electricity from shore power, or diesel fuel from your main engine’s gas tank, or heat coming off the engine itself while you are running down the road. Or a combination of these!

Last winter we were forced to park in the back yard of our old house and the long driveway is lined with vicious tree branches and tight curves, so we didn’t want to go in and out of there any more than necessary. With Aqua-Hot system of heat, we did not have to pull of stakes for the entire winter of below freezing weather. We used about 70 gallons of diesel from our 150 gallon tank.

Not only does “Mr.” Aqua-Hot have three different ways of heating coming IN to the system, he has two different competing demands on him going OUT of the system.

He has to give you both heat AND hot water for your showers. When you combine all of these you get a duke’s mixture of possibilities, depending on how cold it is outside, how many people need a shower, whether you like your room 65 or 70 degrees. Or maybe it’s August and you’ve got the air conditioners running full blast.

Don’t be intimidated. Just approach the thermometer switch on the wall and set it to 70 degrees.  Now walk over to the panel above the driver seat and turn on the Aqua-Hot system with the switch that says “Electric.” Let’s assume for this day you are parked and plugged into 50 watt shore power.

The system has a little tiny plastic sensor in the living room that measures the temperature. Its 62 degrees. He sends a signal to the brain, “Hey, we need more heat out here.” The Aqua-Hot then turns on its electric heating element and begins cooking a tank full of antifreeze (50% water, 50% poison stuff) to 170 degrees. Then it pumps the hot antifreeze throughout the bus to small heat vents/outlets/registers. Just inside these vents are cute little bitty radiators with lots of surfaces. A fan comes on and blows air across these very hot surfaces, then out the vent hole, heating your room.

Now all is well, and you are at a comfy 70 degrees. But wait! There’s more! I said this system was complex and amazing.

This electric heating element continues to work as long and hard and as he can, no matter how cold it gets outside, but there is a limit to his ability. Because, did somebody say “Your turn, honey.”  Now you need shower, and where is all that hot water going to come from?!

Back at antifreeze central, just picture a long snaky pipe filled with clean water. It winds its way through the antifreeze tank, so it also stays heated to 170 degrees, same as the antifreeze. Turn on the hot water faucet on a warm summer day, and you will easily  have enough hot for two showers without any extra effort. But on a cold winter day, and he is working hard to keep the antifreeze at 170 and keep the rooms heated up. If you drain off all the hot water for a shower, you pull a bunch of ice cold water back into the pipes around the heater core, and you are giving that electric element the shivers.

Now he’s crying in pain, and reaches the limit of his electric capacity. Mr. Aqua-Hot  must choose whether to give you heat or hot water. The guys who built this system already told him, “If you get overloaded, forget the heat and just make hot water only. We don’t want the lady of the house hitting ice water halfway through her shower.”

But this is where the genius comes in! When you get in this situation, you just walk back to the panel over the driver seat and you flip the other Aqua-Hot switch, the one that says “Diesel”, and you will hear, from the bay underneath the bus, the sound of a diesel flame heater kicking in. You will come to cherish this quiet, gentle whoosh as the sound of luxury. This is “on demand” on steroids. Within two minutes, you have enough steaming hot water to shower your grandson’s entire little league team. You can now take a long hot shower on a cold winter day, but as you know, we RV’ers are way too sensible for that. And you will probably continue to take your little Navy shower just as always. And by the way, when you take a shower in the wintertime, I advise you to always switch the diesel switch on BEFORE you get into the shower. It’s no fun streaking through the bus soaking wet with no regard for your windows and neighbors.

To keep from scaring you early on, I failed to mention that your bus also has the words ”heat pump,” on the thermometer, which is a whole different system from your Hydro-Hot. We actually never use this heat pump. It is part of the air conditioning system. It uses Freon to heat instead of antifreeze. The only advantage we can see to the heat pump is that it won’t lower the temperature of your antifreeze and your hot water core. On the other hand, the heat pump only works well when the outside temperature is 40 degrees or above. So we’ve always been in the habit of using our furnace only. But would love to see a comparison of electricity usage on heat pump versus furnace.

When we were stuck in Oklahoma for the winter (I’ll explain why below) it drops below freezing at night and sometimes dips below zero. We found out that the electric heater kept us cozy in the daytime, but needed help after sunset. At bedtime we kept the electric heater on, but had to switch on the diesel boost and let that diesel burner run all night long to keep our bus at 65 degrees. Steve estimates we used 70 gallons of diesel over that bitter winter. With our 150 gallon tank, we could easily have lasted through a Canadian winter. It was a great blessing to us not to have to drive to the gas station once all winter. Compare that to propane tanks that must be filled once a week.

We also had to wrap heat tape around our water hose, and leave the faucets dripping all night. Our water hose still froze up on bitter cold nights but the next morning the sun would shine and by early afternoon the hose would thaw. Many times the hose was buried in a blanket of snow, and this actually insulated it from cold, as non-intuitive as that sounds. You can ask the bunnies and polar bears about that.

A couple times our water froze right inside the bay and we found out that ice cold air was sneaking into the bay through the big opening of the sewer hose. It was just like leaving a door open! On extra cold nights we had to go out and unhook the sewer hose and cap off the black tank. And that ended that.

Even if our thermostat on the furnace is set to the “off” position, Mr. Hydro-Hot knows he has to keep making hot water for us. Whenever the temperature of the antifreeze drops below 140 degrees, the electric burner kicks on and reheats it, even on a hot summer day. When we draw hot water, this pulls fresh cold water into the pipe, cools down the antifreeze and signals the burner to kick in. The element heats to a maximum of 170 degrees and then floats, similar to a battery floating to maintain full charge.

Now let’s say we pull our electric plug outside and park our bus on BLM land atQuartzsite,Arizona. We are dry camping for two weeks. What fun for us, and for our flexible, ingenious heating system.  We have no electricity, so we might as well turn our thermostat to the OFF position. We would never attempt to do “dry camping” in a cold climate. But here in Quartzsite, let’s say it’s a balmy 70 degrees outside so we don’t need heat anyway. We can even open our windows. But we would like a little hot water for showers. And how do we turn the lights on?  Hmmm?!

The answer is – generator – that thing your husband rushes to Lowe’s to buy when bad weather hits and power goes out all over town. Your generator runs on diesel so you don’t want to squander it, and it makes noise, so you don’t want to run it at night when other people nearby are trying to sleep. So start it up in the morning and power will flow from generator to inverter, converting that power to electricity. It flows through all the outlets marked “inverter.” Now you can run your lights, coffee pot., toaster oven, radio, computer and big screen TV all at once. The generator will also recharge your house batteries. Once you turn it off, you will still have six fully charged batteries so you can run your TV, computers and lights quietly for the rest of the evening. .Run your generator a couple hours in the morning when you get up, and a couple hours in the early evening, and you are sitting pretty until your diesel runs out, or your dirty tanks get full.

As far as hot water, there is no electric element heating except while the generator is actually running. The burner has been trained to shut off whenever the generator shuts off. Otherwise it would drain your house batteries in a hurry. Even if you have the Hydro-Hot electric switch in the ON position while dry camping, the system will not run off your batteries.

So if you want to take a shower, you can do it while the generator is running. Or if you turn the generator off, the water will probably stay hot for 45 minutes or so. But remember your magic switch – the Hydro-Hot diesel, which you haven’t even touched yet. Just flip it on and the magic diesel burner comes on, heating water with diesel fuel from the motor. It doesn’t even need the generator to do its job! Within two minutes you have enough hot water for that ball team. Seriously, it is heating the water on-demand, just ahead of you. So no matter how long you leave the hot water faucet running. . .I wouldn’t, though, because God only gave you a 65 gallon storage tank for your used (“gray”) water. And once that’s full, you’re up a different kind of creek. Also, you are carrying a tank of 90 gallons of fresh water. Be thrifty with your water usage and you will be able to have fun out in the desert for seven whole days before you have to drive into town to refill your fresh water and empty your used water.

Well class, I think that’s enough for one day. You have to agree the Hydro-Hot system is amazing. It does take maintenance and after several years the heating element, pumps or fans may certainly need to be replaced. You can save a lot of money if you work on it yourself, but some systems are easier to get to than others. In the case of our 2005 Tiffen Allegro Bus, Stephen spent a week with bloody arms and hands and he looked like a sausage with his 6’3″

 250-pound frame stuffed into a tiny opening. Here are a few photos of Steve repairing his system.

Best of luck, guys. We couldn’t live a day without our Aqua-Hot!

 *Why we spent the winter in Oklahoma:

We had a photography business in our home for 22 years. In order to sell it in 2008, we had to hold the note for the buyer. He was newly self-employed, out-of-state, and in a bad economy. We only did it because his parents co-signed and had good financials. The buyer defaulted after one year! We offered to settle for $94 when he owed $5600, He chose instead to declare bankruptcy, taking his parents with him.  What a tragedy. We lost our shirts financially, got the house back and parked our RV in the back yard to babysit the house while looking for a new buyer – one with a bank loan.


– Posted by Carol Ann Dwyer