All electric coach. Space heaters needed?

[Alan Stater]

2024 Newmar MA 4118

Last night I set turned on the Oasis burner and electric #2. I set the interior temperature thermostat to 74 degrees, and floor heat to level 10.

The outdoor temperature last night dropped to 33 degrees, pretty cold. When we awoke this morning, the interior temperature was 61 degrees, not very warm. Not the 74 degrees I had set. I realize the heat pumps are not designed to operate below 40 degrees. I believe this only leaves the heated flooring, and the two internal electric fan heaters. The heated floor was warm in most places, too hot to stand on in a few places, and rather cold in other places, such as under the dining table, and in the stool room, both of which are located on a slides.

I realize this coach is all electric, without a furnace. Am I supposed to use electric space heaters on cold nights?

We will be at the mothership in Nappanee this April for both service and warrantee work. If there's something wrong with the heat on our coach, I'd like to have it corrected in Nappanee.

I thank you all for any thoughts.

[d23haynes57]

Your Oasis should be able to heat the coach on its own, with the burner as the primary heat source. The electric floor heat and heat pumps rely on you having power either from park power or generator.
Your thermostat should multiple settings for each zone. For heat the choices should be gas or electric. On Electric, the system uses the heat pumps as primary and may supplement with the Oasis. On GAs, the system will only use the Oasis. I don't know how your floor heat is controlled. Separate t-stats.
For my Foretravel I have kept the coach warm with the Oasis in temps in the upper teens.

[shepardmike]

It sounds like the Oasis was only running the electric heating elements and not the diesel burner. Make sure you have the setting correct.

[Alan Stater]

Thank you. The heat source (electric or gas) was set on "Auto". I now just changed it to "Both". We are connected to 50A shore power. With this change to "Both", perhaps we'll see a difference tonight.

[d23haynes57]

To put things in perspective. The burner provides a approximately 50K/Btus heater per hour. Both of the electric elements total ~10K/Btus/hr. About the same as 2 normal space heaters. That also tries to heat the tank and plumbing bays.
The only reason they even add the electric option is to help extended the fuel supply when unmetered electricity is available.
Here on Long Island electricity is ~$0.25/KWh. That is $0.75 per hour to run those heating elements. That is ~$0.75 for 10K Btu of heat.
Diesel is ~138,000 Btu heat per gallon. $4/gallon, $0.75 gives ~24,000 Btu even after some losses.

[Dutch Star Don]

You need to learn to manage your coach temps and after a few trips you'll realize what's needed. To start, the floors are not instant heat. In 33-degree overnight weather, the floors should have been turned on when you arrived at the campsite. This gives them time to radiate heat throughout the floors and warm the walls. The original floors had a High, Med and Low setting. The settings are just how many times the floor heat cycles on and off over an hour.

With 33 degree nights, I would have the floors running at about 5 to 7 on your style controls all day. If it gets too warm, turn it down a little. Around dinner time, turn them all too high.

Regarding the Oasis, the furnace is not really designed to heat the coach with just the electric elements. The electric elements can't produce enough heat to get the coach up to temp, unless it's much warmer outside. The coolant never develops enough heat, and the fans run forever trying to get the temp up.

If you want to use the furnace, the burner needs to be on. I was new to hydronic heating and wrote this post when we got our first Newmar with Oasis. It was called Oasis for Newbies. It's a quick read and will help you understand the capabilities of the Oasis unit.

Lastly, the cold spots on the floor are typically where Newmar mounts furniture like the front seats or dinettes. They screw those down so they don't want heated wiring under them that can be punctured by screws.

Oasis Use for Newbies

This is our first coach with hydronic heating and everything was new to me. I like knowing how something works and have done my own repairs and servicing for the past 35 years. We live in California and rarely see really cold days while camping. For that reason, learning how the Oasis system works has been a process. I thought I would post what I’ve learned or the past year for those using a hydronic system for the first time. This may be too basic for some and I apologize in advance. If you see any obvious mistakes, please feel free to correct me so we can get the best info out there.

The Oasis "Heating Module", on my coach, is located on the driver’s side about mid coach. When you open the bay you’ll see the rubber push button to power the unit "Power On’. The Oasis system has a second unit, called the "Distribution Module" which is located close to the heating module. Mine is located directly behind the heating module and is accessed from the passenger’s side bay.

When the coach is not in use, the Oasis unit is turned off at the power switch on the front of the unit. Before a trip, I typically turn the unit on a day before so I don’t forget. Simply turning the unit on does not activate any heating.

Side note: The Oasis unit on Ventanas and Dutch Stars, when turned on, will allow the engine coolant to heat the unit while driving. This means that when you arrive at your destination, you’ll have hot water and the ability to turn the furnace on and immediately have heat. On models above the Dutch Star, the heating works in reverse and the Oasis system can be turned on to preheat the engine coolant before travel. This option can be added to the Dutch Star and Ventana (see QT’s by PDR John).

Once you arrive at your camping destination, you have a choice of methods for heating the unit. The Oasis unit can be heated electrically by two heating elements or by the diesel burner. The controls for the unit are located in the control panel above the windshield. The two heating elements can be turned on separately or together. Typically, if you’re on 30 amps, you would use one element. 50 amps would allow both to operate at the same time.

Side Note: When the electric elements are turned on, the indicator lights, adjacent to the electric element switch will light. Once the unit reaches temperature, the lights will shut off.

The diesel burner is also turned on at the control panel and can run in parallel with one or both electric elements.

The Oasis system has a "summer loop" and a "winter loop". The word loop refers to circulation of the boiler fluid. In the "summer loop", only water for the faucets and shower are being heated. In the "winter loop", boiler fluid is being circulated to the various heat exchangers (small radiators in the coach).

The "summer loop" is activated by turning on one or both of the heating sources (electric or diesel) while keeping the "Furnace" turned off at the thermostat. In this mode, you’ll have unlimited hot water.

The "winter loop" is activated by turning the "Furnace" on at the thermostat. You can leave the "Furnace" temp at a level below that of the coach and the system will continue to stay in "winter loop" and circulate boiler fluid to the various heat exchangers. When the thermostat temp is increased to something above room temperature, fans located behind each heat exchanger will come on and begin heating the coach.

There is a reason for a "summer loop" and a "winter loop". If you leave the coach in "winter loop" (Furnace on) during hot weather, boiler fluid will continue to be circulated to the heat exchangers. Even though the fans aren’t running, the exchangers will radiate heat, unnecessarily raising the interior coach temp .

The use of the Oasis system has been a learning experience for me. It takes some managing depending on how you like to use it. We recently did our first really cold weather trip and I learned several things, which is primarily why I’m writing this.

Depending on how you use the system, it requires some management. We arrived at a campground with an outside temp of 40 degrees. We had full hookups, so I turned on just the two electric elements. We like to sleep with a cool coach and I set the furnace to 60 degrees. In the morning, I turned up the furnace to 68 degrees and my wife jumped in the shower. The heater was still running and trying to bring the coach to temp. My wife ended up with a lukewarm shower.

The heater shut off at 68 degrees and I took my shower. It was hot. I thought the running of both electric elements would be the equivalent of running the diesel burner. Not so. Several factors came into play. The ground water was very cold and was being fed directly into the system when we showered. (Oasis technicians recommend using the onboard coach water in really cold weather and then replenishing it later.)

During our summer trips, we found two electric elements were plenty for a hot shower, especially since the system was not heating boiler fluid for the heat exchangers. Now in cold weather, with the heater running and showering at the same time, we needed the diesel burner and both electric elements. On this same trip, we boon docked for 5 days. The diesel burner is sufficient to heat everything by itself.

So here’s what we found. If we have 30 amp or 50 amp hookups during a summer trip, we’ll turn on one or both electric elements and have hot water. If we have 30 amp or 50 amp hookups during a cold winter stay, we’ll turn on both electric elements and the diesel burner. The electric burners will maintain temp and the diesel burner will supplement during high demand.

It’s apparent the diesel burner will provide all heating needs, but I don’t like to leave it on as the sole source of heat in a campground with hookups. Running the electric elements and the diesel burner will keep it from running unnecessarily.

Some other things.....When we first got the coach, I didn’t feel that the shower was getting as hot as it should. I called Oasis and they recommended that I turn up the flow valve. The valve is located inside the "Distribution Module" and requires removing the cover. This helped, but didn’t solve the issue. Another poster recommended that I remove the handle on the shower faucet and look for a restrictor. Sure enough, there was a red plastic ring used to restrict the travel of the handle. I removed the restrictor and have been very satisfied with the temp.

Oasis offers a service kit for $100.00. It includes tune parts, filters and a large diesel fuel filter. The filter is similar to the engine filter and is located in the generator bay on my coach.

The unit also uses Century Transfer Fluid in the boiler system. The overflow canister for the system is at the rear of the coach in the engine compartment.

[wildcat30]

Hi Alan, we have the same coach!

Regarding heat in your floors, remember that the heating mats (under your tile) do NOT extend under the tile of your slides. So under the dinette or directly in front of your dresser/wardrobe in the bedroom, those tiles are not heated. As Dutchstar Don said, it can take some time to figure out what works for your comfort level of heat and what combinations of sources to use: Oasis heat, floor heat or heat pumps (heat pumps when temps are above 40-degrees)

Note the radiant floor heat in your coach works on a 20-min cycle as follows:

• One bar: Floor Heat Off
• Two bars: Store mode (Floor Heat will not operate in this mode)
• Three bars: On ~2 minutes (“Off time” Remainder of 20 min. cycle)
• Four bars: On ~4 minutes (“Off time” Remainder of 20 min. cycle)
• Five bars: On ~6 minutes (“Off time” Remainder of 20 min. cycle)
• Six bars: On ~8 minutes (“Off time” Remainder of 20 min. cycle)
• Seven bars: On ~10 minutes (“Off time” Remainder of 20 min. cycle)
• Eight bars: On ~12 minutes (“Off time” Remainder of 20 min. cycle)
• Nine bars: On ~14 minutes (“Off time” Remainder of 20 min. cycle)
• Ten bars: On ~16 minutes (“Off time” Remainder of 20 min. cycle)
• Eleven bars: On ~18 minutes (“Off time” Remainder of 20 min. cycle)
• Twelve bars: Heat mat is activated (constantly on)

[MarkMaxPayne]

In the winter you should be able to take the coach from below freezing (even in the high teens) to the 70's in less than a couple of hours. I do this more than once a month on my rig. While in storage for winter I start my generator and let it run for a couple of minutes to warm up.

I then go to the climate menu, oasis, turn on my burner and both AC elements, set mode to both (or sometimes even automatic), go back to climate and select heat for all zones. I also make sure to have the Oasis fan switch on the dash set to ON so the register under the dash center console (floor level at the kick plate under the drawers aiming at main room of coach) cycles on and off with the rest of the Oasis registers. Forgetting this fan register can almost double the time it takes to heat the coach.

After about 2-3 minutes of the Oasis warming up (mainly by burner) all the registers will kick on. The roof AC/Heaters also cycle blowing hot air as well. In about an hour and a half to two hours the interior is toasty.

Before I turn off my generator I go to the climate menu, turn off the heat for all zones, go into Oasis and turn off the burner and 2 AC elements. After the generator has been without the load for a couple of minutes I then turn it off.

On my previous rig (a Tiffin) I used to have to trick the roof AC/heaters to work along side my furnace by setting my desired temp to no more than 4 degrees above the current temp. Once that was reached I'd bump the desired temp up another 4 degrees. Rinse/repeat until in the seventies. If they quit coming on, verify the delta in current temp from desired was 4 degrees or less. On my Newmar I was delighted to find I didn't need to use this trick; it just works.

Best,
-Mark

[NCC-1701A]

A couple of weeks ago we were in the parking lot of Midway RV in Grand Rapids, MI the first night in our new-to-us 2021 3545 New Aire. We had just traded in our 2013 MA 4336.

It was cold and temps dropped to 10° F that first night. I had the system on the Oasis with the burner going all by itself...neither of the electrical elements. I set the temp throughput the coach at 70. I also had the floor heat set at 6. The coach held temp perfectly. We stayed in the lot three days at those temps...no issues.

Thx Wildcat for explaining the floor heat settings. I only had low, medium, and high on my MA and low was always great plenty. I haven't gone through all the details in the manuals yet, so was a bit disappointed with the floor heat on the low end in the New Aire. I was correlating a 2 or 3 setting with "low" and per your scale, especially at the temps we were at, that was nothing!

[d23haynes57]

Is your floor heat electric? Were you running the generator just for the floor heating?

[Alan Stater]

I thank you all for your help!! I tried turning on the Oasis burner, and electric 1 &2, then set the heat to "both". In the mornings the inside is toasty! I love this forum!! I thank you all again!

[wildcat30]

Glad you are toasty now! These things have a bit of a learning curve...ask me how I know...

[twojayhawks]

Originally Posted by Alan Stater

I thank you all for your help!! I tried turning on the Oasis burner, and electric 1 &2, then set the heat to "both". In the mornings the inside is toasty! I love this forum!! I thank you all again!

Sounds like you are all dialed in. When I got my DS 10 years ago I was new to Oasis & I overused the burner. Nothing wrong with using the burner at all it uses so little fuel it's not even worth mentioning. In time I realized in many applications the electric alone is all that's needed. I leave AC1 on 7/24 for summer camping and AC2 on 7/24 for cold camping. With night time lows in the 30's, using floor heat, stat on furnaces, I can heat the coach just fine with electric only. Newmar coach's are very well insulated. I don't use the heat pumps, personal preference, so strictly furnace & floor heat for us. Obviously if the coach accidentally dropped to low 60's overnight like you described & you want it warm asap the burner is required, electric only will not be up for the task. Lastly, if you are maintaining comfort level with electric only you likely will still need the burner for showers. In our coach we typically turn burner on for showers & then off after that in cold temps. Summertime camping burner is typically not used at all.

[Alpine36]

Space heaters…I never leave home without a couple. Just be sure to use them safely and run them on separate circuits. If your paying for FHU why pay to operate your petro based furnace? Earlier this year we developed a leak at the fresh water pump inlet filter, which flooded the basement with about 50 gallons of water while in transit. Sure glad I had those heaters and a small wet/dry shop vac with us.