Community Forums

Max Hubrich · 01-06-2010, 09:39 AM

We are experiencing unseasonably cold weather here in South Mississippi.

We've been down to 25 F twice now. The hose fittings and external water filters on other RV's are busting around here like popcorn.

I guess I've not used the combination of heat pumps (2) and the furnace before. I had weird things (so I thought) happening. I finally dug out my operators manual for the Duo-Therm control unit.

This is what I found and it might be of interest to some of you folks with similiar units- (I have the 5 button control- vs the 4 button):

"When in the HEAT PUMP mode, if the outside ambient temperature is measured to be below 30 F and the vehicle is equipped with a furnace connected to the Comfort Control Center, the control will automatically select the FURNACE operation and the HEAT PUMP will shut down.

When this happens, the AUX. HEAT and the HEAT PUMP indicators on the LCD will illuminate. Once the outside ambient temperature is measured above 38 F, the control will return to the HEAT PUMP operation and shut down the furnace if it is connected to the Comfort Control Center."

Golly, again--- It's all automatic!!

So there you are---

-- Hope this helps someone understand the system better than I did

.

GaryKD · 01-06-2010, 10:03 AM

Hi Max,
Does your coach actually work this way? I'm attending the Tampa RV Super Show next week. This may be the first time I get to check to see if this feature works.

Thanks for the post. I thought the only EMS in my coach was me.

buck62 · 01-06-2010, 10:17 AM

Mine works automatically exactly as you described. I always have it on the heat pump setting since I am getting electricity included with the camp site fee. If the temperature drops below the heat pumps set temperature limit the gas furnace kicks in automatically to supplement. Pretty neat system.

Route 66 · 01-06-2010, 10:17 AM

Max is correct, except I believe most rigs, mine included, switch to the furnace when the outside temps are in the high 30's.

The furnace is controlled by the zone 1 (front ac/hp) settings, so make sure you have the zone 1 temp set where you want it.

Also as temps approach 40*, the HPs will periodically go into the defrost mode, which sounds bad, but it's normal.

MonacoMama · 01-06-2010, 11:52 AM

Gosh...I almost missed this post!

Max - we have a similar system, but our system is set to switch to the furnace when the outside ambient temps are in the low 30s.

We also have a switch on our Control Panel that is called "System Heat". We will turn that switch on when we might experience cold weather. It does not kick on until the temps in the wet bay reaches into the very low 30's too. This turns the heater on in the wet bay to avoid freezing.

BTW...I used the foam pipe wraps on my water hose and also a styrofoam cap on the top of the spigot to avoid broken pipes when I was up in the snow.

Route 66 · 01-06-2010, 11:57 AM

It sounds like the Monaco system is different than the Newmar/Dometic system being discussed here.

MonacoMama · 01-06-2010, 12:01 PM

Quote:

Originally Posted by Route 66

It sounds like the Monaco system is different than the Newmar/Dometic system being discussed here.

...yes & no...which is why I brought it up.. since this is not in the Newmar section - I felt folks should know that their system might be different

. You might notice other members besides me answering are not all Newmar owners!

tmar10 · 01-06-2010, 01:09 PM

Our system functions the same way. The furnace is ducted to the basement area while the heat pumps are ducted through the roof vents. Regardless of the need for heat in the basement areas, the heat pumps are not real effective as the temps fall toward freezing without the support of the furnace and heat strips.

Max Hubrich · 01-06-2010, 05:05 PM

Garykd,
My system works exactly the way I described it in the original post.

Route66,
Thanks for your concern. I didn't post the reason I entered this thread here- but it's because a widow, and friend of ours, ran out of propane and her rig got real cold. She has a Monoco Monarch SE. It has the exact same system as mine. When the ambient temperature went below 30 F yesterday morning she ran out of propane and had no source of heat except for two Pelonis units she had in her rig. When I went over to her coach I hooked up a full propane tank for her and then the furnace kicked in. later in the day as it warmed up the heat pumps came back on. I got into my manuals and operating booklets and our two systems work identical.

Her husband drove the brand new Monarch for 15 miles before he died. She lives in it full time and some other folks hooked an auxillary tank system into the coach's internal propane system. That's what "Bill", her husband, wanted. They moved out of a large 5th wheel where he had auxillary tanks before.

I just thought since hers is a Monoco and mine is a Newmar, some of the coaches we own, run similiar systems.

MM,
Hi,

By the way, since so many folks are letting their water run during the night and an above ground water pipe got a crack in it (from the freeze), we have low water pressure. Our Oxygenics shower head is great

. I know I can run the 5.7 GPM water pump, if needed, but we are fine without it.

In summary, with a system such as mine, all one has to do is set the temperature you want on the heat pump at bed time, zone 1, make sure you have adequate propane, and you'll hear the furnace roar into life as it gets below 30 F degrees. That will put heat into the bays (as long as the basement fan switch is on) and keep you comfortable in the coach. Next day as things warm up the heat pump/s will come back on and the furnace will turn off automatically.

Cheers,

bdaball · 01-06-2010, 07:22 PM

Hey Max,
You sure would need both of those systems here now up at the HABAH!

I got to try that in the morning to see if mine works the same. Pretty sure I don't have to worry about if it's high 30's or low 30's. We haven't seen either one of those recently and looks like we won't either before we leave.

RV Wizard · 01-07-2010, 03:38 AM

The heat pumps are not actually measuring outside temperatures to bring on the auxiliary heat. The "freeze sensor" detect the evaporator coil is freezing up and causes the change over. This can happen at many different outside temperatures, depending on relative humidity and how long the unit has been in operation. These units do not have a defrost cycle like residential or commercial heat pumps; they just shut down and change over to auxiliary heat. For the auxiliary heat to work, you will need to have that system working, have fuel and the proper controls set if you have hydronic heating. Good luck and everyone stay warm.

Route 66 · 01-07-2010, 06:15 AM

Quote:

These units do not have a defrost cycle like residential or commercial heat pumps; they just shut down and change over to auxiliary heat.

Mike, can you clarify?

When it's around 40* or lower, my heat pumps periodically stop blowing air, make strange noises and go through what I've always understood to be a defrost cycle.

Tincup · 01-07-2010, 07:27 AM

GAD ZOOKS

the wonders of electronics never ceases to amaze me!
Our '05 Bounder works the same way

Gary RVRoamer · 01-07-2010, 10:45 AM

My Coleman heat pumps also seem to pause for awhile and then resume when it gets cold outside, e.g around 40. When that starts occuring frequently, I shut it down, so I don't know if it would activate my aux heat or not. I do know the t-stat doesn't switch on the aux heat (propane furnace in my case) until there is a 5 degree difference between the set temp and the actual interior temp.