Oasis and roof mounted HVAC

[Bird Dogs]

We are new Newmar owners but have had several RV’s over the last 30+ years. So I think/thought I understand the heating cooing components.

But. There’s always a but. We recently, 4/27, purchased a 2018 4018. Haven’t used it much, 1 night, an entire thread all on its own related to a certain dealership.

When we were on the maiden voyage I was running the Oasis system to heat the rig and the roof AC/Heat Pump fans would run when the Oasis system was calling for heat. Not heat out of the ceiling units just the fans.

Is that the normal operating mode. Or, did I miss something.

[Dutch Star Don]

We don't use the Oasis or heat pumps for coach heat, unless we're boondocking, so it's rare. If I recall, the fan setting on the thermostat determines how the system functions. Again, if I recall correctly, if the fans are on AUTO, it will select the best heating method.

Switch the fans from AUTO to High, Medium or Low (manual setting) and see what happens.

[Bird Dogs]

It’s been a couple weeks since I’ve seen the rig and can’t remember what settings I tried on the thermostat.

I’ll give it another go when we get it back on Friday(?).

Thanks for the response.

[150man]

Heat pumps are not effective when it’s below 40 degrees out they wil, blow cold air.
Found this out the hard way in our first coach. Woke up with cold air blowing over the bed after several rounds of rock paper scissors under the covers I had to get up and start the furnace.
Our go to now is the heated floor wife and the stupid cats love it

[Suburbazine]

Originally Posted by Bird Dogs

We are new Newmar owners but have had several RV’s over the last 30+ years. So I think/thought I understand the heating cooing components.

But. There’s always a but. We recently, 4/27, purchased a 2018 4018. Haven’t used it much, 1 night, an entire thread all on its own related to a certain dealership.

When we were on the maiden voyage I was running the Oasis system to heat the rig and the roof AC/Heat Pump fans would run when the Oasis system was calling for heat. Not heat out of the ceiling units just the fans.

Is that the normal operating mode. Or, did I miss something.

Does it have the Newmar thermostat or did someone replace it with a Micro Air?

[WILDEBILL308]

Originally Posted by Bird Dogs

We are new Newmar owners but have had several RV’s over the last 30+ years. So I think/thought I understand the heating cooing components.

But. There’s always a but. We recently, 4/27, purchased a 2018 4018. Haven’t used it much, 1 night, an entire thread all on its own related to a certain dealership.

When we were on the maiden voyage I was running the Oasis system to heat the rig and the roof AC/Heat Pump fans would run when the Oasis system was calling for heat. Not heat out of the ceiling units just the fans.

Is that the normal operating mode. Or, did I miss something.

When you want to use the Oasis for heat turn each of the zones on the thermostat to furnace.
Bill

[WILDEBILL308]

Originally Posted by Dutch Star Don

We don't use the Oasis or heat pumps for coach heat, unless we're boondocking, so it's rare. If I recall, the fan setting on the thermostat determines how the system functions. Again, if I recall correctly, if the fans are on AUTO, it will select the best heating method.

Switch the fans from AUTO to High, Medium or Low (manual setting) and see what happens.

Don, what do you use for heat? The Oasis or heat pumps is about it. I wouldn't think heated floors would keep up if you had them.
Bill

[Dutch Star Don]

We hadn't intended to order heated floors when we ordered the coach new, since we live in California. My dealer convinced us to add them to the build. It is probably the best feature on our coach. In the five years we owned the coach, we've only used the Oasis for furnace heat on a few occasions where we didn't have hookups. However, when we have 50 amps, the heated floors have kept the coach toasty in weather down to the 20's. In really cold weather, we let them run all day on high. No noise and VERY even heating throughout the coach.

On our previous DS, without heated floors, we had the fireplace which kept the front of the coach very warm. At night we would leave it on and let it migrate to the bedroom, where we liked it a little cooler. On occasion, we would use the heat pumps, on the other DS. We would turn the bedroom unit on while up front and then switch to the front unit when we went to bed. That kept the noise down.

[d23haynes57]

Your set is probably similar to mine. Your thermostat has multiple zones. If you have 3 rooftops you should have three zones.
Each zone can be set for different fan and heat source combinations. With the main slide switch set to heat, you need to go t each zone and confirm it is set "gas" not "elec". This should then operate the hydronic heater fans only.

If using the heat pumps, it does take some time for them to actually blow warm air. Mine take about 15 to 20 minutes. It mostly only makes sense to use them when plugged in or running the generator for other reasons. Note that for winter use the Oasis also heats the water compartments and may also have the ability to pre-heat the engine.

[WILDEBILL308]

Originally Posted by d23haynes57

Your set is probably similar to mine. Your thermostat has multiple zones. If you have 3 rooftops you should have three zones.
Each zone can be set for different fan and heat source combinations. With the main slide switch set to heat, you need to go t each zone and confirm it is set "gas" not "elec". This should then operate the hydronic heater fans only.

If using the heat pumps, it does take some time for them to actually blow warm air. Mine take about 15 to 20 minutes. It mostly only makes sense to use them when plugged in or running the generator for other reasons. Note that for winter use the Oasis also heats the water compartments and may also have the ability to pre-heat the engine.

The OP has a Oasis system it does not use gas/propane.
Bill

[WILDEBILL308]

Originally Posted by Dutch Star Don

We hadn't intended to order heated floors when we ordered the coach new, since we live in California. My dealer convinced us to add them to the build. It is probably the best feature on our coach. In the five years we owned the coach, we've only used the Oasis for furnace heat on a few occasions where we didn't have hookups. However, when we have 50 amps, the heated floors have kept the coach toasty in weather down to the 20's. In really cold weather, we let them run all day on high. No noise and VERY even heating throughout the coach.

On our previous DS, without heated floors, we had the fireplace which kept the front of the coach very warm. At night we would leave it on and let it migrate to the bedroom, where we liked it a little cooler. On occasion, we would use the heat pumps, on the other DS. We would turn the bedroom unit on while up front and then switch to the front unit when we went to bed. That kept the noise down.

Just as long as you know the heated floors don't do that good of a job heating the basement and wet bay when it is realey cold. Last year when it was 18deg hear I checked an my wet bay was 48. I didn't winterize just left Oasis on. I just used the electric heating elements.
I find the Oasis pretty quiet when on the electric elements. The burner is a little nosier but most of the time doesn't bother me.
Bill

[d23haynes57]

Originally Posted by WILDEBILL308

The OP has a Oasis system it does not use gas/propane.
Bill

Mine with the Oasis system does not use gas or propane but that is the wording on the thermostat LCD display.

[Bird Dogs]

I started this thread last summer then got side tracked and since we didn’t need the Oasis system to heat the rig I forgot about it.

To refresh, we have a 2018 DS 4018, 2 zone HVAC system w/heat pumps and an Oasis system.

I’m familiar with heat pump operation and use. I’ve gone through the thermostat and confirmed I’ve selected the correct mode for both zones and the fans/zones are not set to Auto.

I’ve confirmed the Oasis system operates. Ignites, runs and is circulating to the heat exchangers.

Issue is, when I select the Oasis mode my heat pumps (or at least the fans ) come on. The Oasis system also comes on.

Could it be an issue with the Dometic thermostat?

Thanks for the help, I appreciate the knowledge base.

[Suburbazine]

That's a programmable option to enhance air mixing and prevent stratification (hot ceiling/cold floor)

I'm not sure if you can control it.