Heat Pumps on Carbon 357?

rzrbckr · 02-11-2018, 07:57 AM

Just took possession of our new 2018 Carbon 357. The ac/heater controller has a setting for electric heat which starts the ac units but no heat is coming from the registers. Only cold air. Does anyone know whether they are supposed to be heat pumps or just ac units? It’s cold here in south TX today!

**chuckster57** · 02-11-2018, 08:24 AM

I would look at the owners packet. It will have the “build sheet” and/or the owners manuals for the A/C units.

Depending on how cold it is, heat pumps won’t operate, you’ll have to use the furnace. IMO heat pumps aren’t designed to “heat” the unit up first thing in the morning, but better for “maintaining” the temp.

ChuckS · 02-11-2018, 08:37 AM

Most likely only one of those AC units will provide heat ...

We use ours but when temp is below 36 we first fire up standard furnace to take edge off. Then run the heat pump

In the case of my unit the rear AC is also a heat pump and I have to select the right zone to run the right AC

I think you Carbon has 3 Ac units so you would need to find which one is what.

I typically feel heat from the HP within 3 to 5 minutes coming out of AC vents.

Sent from my iPhone using Tapatalk

travelin texans · 02-11-2018, 09:32 AM

Typicaly 40 degrees or lower they will only blow cold. Anything below freezing you should run the furnace as it has ducts to the underbelly to help keep tanks & plumbing warmed.

dcg9381 · 02-11-2018, 10:14 AM

I'm not sure that "electric heat" is the same as a heat pump. Your carbon should have come with a packet of docs. What AC (make/model) is in those docs?

There ARE heat pump AC models. There are also "aux heat" strips that can be added to AC units. I have a 15 Carbon 327 - and although the option is there at the thermostat, it does not have heat strips or a heat pump AC unit.

In all likelyhood, as indicated, even if you do have 1500 watt heat strips, these are over powered by the amount of air flowing through the units. That is, they DO heat (if you have them) but it's not enough of a temperature difference to feel at the register. They will help heat the unit. On mine, a stand alone 1500 watt heater provides comfort to about 47 degrees ambient, then it starts to lose. 2 of these heaters work into the high 30s.

If your unit is like mine, running the ACs (even on low) result is a bit of a roar. I prefer to use the stand alone units which are quiet - or (if you have it) the electric fireplace option.

**chuckster57** · 02-11-2018, 10:32 AM

Depending on the brand of thermostat, the heat pump is listed as electric heat and furnace is listed as gas heat. Coleman Mach is that way. The Dometic LCD “3 button” shows heat pump.

rzrbckr · 02-11-2018, 01:11 PM

Quote:

Originally Posted by chuckster57

Depending on the brand of thermostat, the heat pump is listed as electric heat and furnace is listed as gas heat. Coleman Mach is that way. The Dometic LCD “3 button” shows heat pump.

I’ll have to get back over to the TH tomorrow to take a look at the manuals. I do have the Coleman Mach’s for ac units. It was well down into the mid 30’s this morning. May have just been to cold last night for them to keep up. I ended up switching to the furnace to keep everything warm.

Also found out the furnace output balance isn’t very good. Bedroom and bath stay about 10 degrees warmer than salon space. I’ll have to dig into that more as well.

travelin texans · 02-11-2018, 02:49 PM

Also if you have a heat pump with tstat set on"elec" there's a 3-5 degree differential between set temp & ambient. If you turn on the heat pump & set at say 68 & the ambient is say 63 the furnace & heat pump both will start til the temp raises to 68 then only the heat pump will run. Some in the other direction, temp set at 68 & heat pump can't keep up, once the ambient temp drops 3-5 degrees the heat pump will shut down & furnace will start.

rzrbckr · 02-11-2018, 03:23 PM

Quote:

Originally Posted by travelin texans

Also if you have a heat pump with tstat set on"elec" there's a 3-5 degree differential between set temp & ambient. If you turn on the heat pump & set at say 68 & the ambient is say 63 the furnace & heat pump both will start til the temp raises to 68 then only the heat pump will run. Some in the other direction, temp set at 68 & heat pump can't keep up, once the ambient temp drops 3-5 degrees the heat pump will shut down & furnace will start.

Ok you just cured my insanity. I was tryin to figure out why the furnace was kicking on too!

dcg9381 · 02-12-2018, 02:33 PM

In my experience with residential heat pumps, once you get into the 30 degree temp zone, you're not going to get much performance out of the systems. I often switched to "emergency heat" (heat strips) just to stop the compressor from turning all day long...

Pull Toy · 02-12-2018, 03:05 PM

One issue I didn't see addressed is the four distinctly different heat sources commonly found in todays RVs.

1. Propane Furnace (12 volt) using floor ducting. If one area seems cooler than other area, try temporarily obstructing air flow till a more satisfactory balance is achieved. This is the only heat source that works in Artic Package to heat the basement, and tanks. If you don't feel you need heat down there, this is the first area to try restricting IMHO, to force more air upstairs. One common problem is kinked vent hoses, worth a look. Adjustable after market vents are available to fine tune your living areas.

2. Newer units are now coming thru with a heat pump in one of the roof a/c's. Using shore power they do a good job of keeping the chill out 'till about 35 - 40 degrees. Below that they are a no show. Don't waste your time.

3. Higher end rigs now are now more commonly coming through with electric fireplaces. They won't keep you from freezing up, but will take the chill off, with a romantic touch to boot!

4. Last and definitely least (IMHO), comes the a/c "add on" heat strip ($$$$) an expensive accessory waste of time and money. On a warm day they will keep you warmer! LOL Don't waste your money, get down to Wally-world, or Costco and buy a cheap electric portable space heater, if it is that chilly.

Many of these options will work well in conjunction with each other, some better than others. We do great in the fall using the fireplace, and the heat pump together. Best of all, it's all 110v, so no propane empties at zero dark thirty.

How you will need to make your various thermometer settings, and adjustments is something to discuss with others using the same systems. There is no one size fits all answer that I'm aware of. There is a lot of self help available on the internet.

Good Luck,

rzrbckr · 02-12-2018, 03:42 PM

Thanks for all the reply’s. Was really wondering if any other 357 owners knew one way or the other knew for sure if they were heat pumps or not. Salesman didn’t know. The literature I have is useless as usual and doesn’t say.
Weather that day was around 38. Yes cold but still should have had some heat produced from the units. Propane furnace works great. Only one small register in garage for furnace heat so was hoping for more heat from heat pumps (if that’s what they are). Guess I’ll give Keystone a call and go from there to get details.

JimQ · 02-12-2018, 04:59 PM

Great advise from the forum members. Steve: Pull Toy: excellent post with good suggestions. When we camp in the spring and fall, I generally run a space heater to supplement the TT furnace, or run the space heater solo to get the chill out. I also run the space heater off of an extension cord directly from the campground pedestal. As you can see from my signature, I have a basic TT so I have no heat pumps. They sound complicated. I do like to keep things simple.

rzrbckr · 02-12-2018, 05:27 PM

They sound complicated. I do like to keep things simple.[/QUOTE]

Simple is much better. I think I’ll be putting a space heater back in the garage for the next cold snap!

**chuckster57** · 02-12-2018, 05:50 PM

Actually heat pumps are simple. Just an AC running in reverse.

Butchh · 02-13-2018, 08:19 AM

Quote:

Originally Posted by rzrbckr

I’ll have to get back over to the TH tomorrow to take a look at the manuals. I do have the Coleman Mach’s for ac units. It was well down into the mid 30’s this morning. May have just been to cold last night for them to keep up. I ended up switching to the furnace to keep everything warm.

Also found out the furnace output balance isn’t very good. Bedroom and bath stay about 10 degrees warmer than salon space. I’ll have to dig into that more as well.

The easiest way to fix the 'balance' issue is to buy floor vents with dampers installed, just like your house. We had to do this with our last fifth wheel and have already bought them for our new one.

Hope this helps.

dcg9381 · 02-14-2018, 04:56 AM

I have the Coleman Mach 3s on my 2015 Carbon. No heat pump function. No heat strips (although I bet these are pretty easy to install). No way the heat pump OR heat strips keeps up with the heating needs when it is 30 outside.

Like yours, the furnace venting is a tad misbalanced.. Lots o heat though...

I think there are a few photos around of someone adding the electric fireplace (heater) to a Carbon - it fit well and looked factory.. Or space heater options, which are much more quiet than the furnace of running the Mach 3 units...

Good luck! Enjoy it!

rzrbckr · 02-14-2018, 05:13 AM

Quote:

Originally Posted by dcg9381

I have the Coleman Mach 3s on my 2015 Carbon. No heat pump function. No heat strips (although I bet these are pretty easy to install). No way the heat pump OR heat strips keeps up with the heating needs when it is 30 outside.

Like yours, the furnace venting is a tad misbalanced.. Lots o heat though...

I think there are a few photos around of someone adding the electric fireplace (heater) to a Carbon - it fit well and looked factory.. Or space heater options, which are much more quiet than the furnace of running the Mach 3 units...

Good luck! Enjoy it!

Thanks! We will most likely be putting a space heater back in the garage if any more trips when it’s cold. And yes, that furnace is more than up to the challenge of heating the rest. Especially the bedroom and bathroom!

rzrbckr · 02-14-2018, 05:16 AM

Quote:

Originally Posted by Butchh

The easiest way to fix the 'balance' issue is to buy floor vents with dampers installed, just like your house. We had to do this with our last fifth wheel and have already bought them for our new one.

Hope this helps.

Thanks Butch. I’ll have to look into that option.

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