Community Forums

Doug427 · 02-10-2021, 03:27 PM

My coach is a 2005 Mountain Aire 43' with a HydroHot system installed when new. I'm in Houston, and between the warm weather that's typical here and the fact that we both strongly dislike cold weather and never RV in it, I have no idea the capabilities of the Hydro Hot system beyond using it for hot water.. I don't even know how to turn on the heat to heat up the coach. We just keep the unit parked when it's cold outside. Neither of us like cold weather.

Now, we need to use the heat for two reasons - my vacation this year is next week, (the timing was not by choice), and we are heading for Big Bend park, our first trip of any length since we bought the coach last year. It's going to be cold at night in Big Bend, so we're going to be needing the heat. Additionally, there is a deep cold snap coming for a few days and temps are expected to drop into the teens overnight, which is extremely rare down here. I'd hate to winterize the whole coach (I have never done that and have no idea how anyway) when the temps will be dropping on Sun and Mon night and then have to normalize it (is "de-winterize" a word?

) when we leave early on Tuesday morning. My local repair guy says that he thinks the Hydro Hot unit is designed to heat the basement and wet compartments as well as the inside, and if I just leave the heat on for a couple of days during the short abnormal cold snap until we leave everything should be fine.

Do any of you guys who are familiar with this type of coach or heating system know if that is in fact correct? Does the HydroHot system actually heat the basement and wet bay as well as the coach interior? I also noticed that located by the rear sink there are switches for some type of heat pads. I assume these pads in the wet area? I don't have access to 50a where I park, all I have is a 15a or 20a 110v plug. Will that be enough to run the Hydro Heat in diesel mode? What about those pad switches - should I do something with them? Will they also work on the same 110V along concurrently with the heater? How would you guys handle all this?

Lastly, it's going to be cold on the drive out there. First stop along the way will be San Antonio (Bourne, actually) for a couple of days. How do I use the heat just to keep us warm while driving? Do I have to run the generator while driving for the heat to work like we do with the A/C units? I guess I just run the heat like we do the A/C - put the two thermostats in heat mode and set the temp? We have two Dometic DuoTherm thermostats. Is there more than one heat mode on the thermostat and in the heating system, like electric or diesel? I would prefer to run it in diesel mode while we drive if possible. I know the hot water part of the HydroHot system can be run in electric mode or on diesel, we use electric when hooked up at a campground, and it works surprisingly well in electric mode. It's just the two of us and both of us take average to longer length showers, and we've never run out of hot water in electric mode. I'm not sure if the heat is dual mode as well.

Any and all tips and advice you guys can lend would be greatly appreciated. We have zero cold weather experience in this coach (or any for that matter). We just don't like cold weather and when it's cold, which is anything below 50 here in Houston for us, we just stay home.

I just had a full and complete service done on the coach - oil, filters, fuel filters on gen and engine, and had the whole Hydro Hot system serviced. We did a complete punchlist service on the entire coach fixing absolutely every little item that was wrong, and also I also did a full service myself on the Jeep Liberty we're towing. We pick it up on Friday from the repair center and we hit the road on Tuesday at 6AM. This cold snap was the last thing we needed to complicate things, but it is what it is.

azSkier · 02-10-2021, 04:19 PM

Turn on the hydrohot electric and diesel switches as you would for hot water, then use your thermostat to turn on the furnace. Zones 1, 3 and 4 have furnace capabilities. Rooftop heat pumps only work down to 40 degrees, below that, hydrohot and furnace are the only way to stay warm.

kenwyatt · 02-10-2021, 04:30 PM

I live in B/CS and this is what I do. Turn on the Elec AND diesel switches. Set the thermostats to about 40. I also turn on my 2 elec baseboard heaters to low. One is in the toilet area and one in the kitchen. Open the cabinet doors. It will heat the water tank area automatically when the temperature gets about 37. I stay plugged into a 50 amp service. Have been doing it for 3 years without a problem. Number is 817-715-0137 if you want to chat about it

Nildecaf · 02-10-2021, 04:48 PM

Don't forget to disconnect, drain and stow your fresh water hose so it doesn't freeze and burst at night.

azSkier · 02-10-2021, 05:06 PM

Make sure the heater in the wetbay is working. Turn on Zone 3 to get heat to the radiator.

Doug427 · 02-10-2021, 05:23 PM

Thanks for all the replies. Questions I have are:

A) I can only plug into 110 volts between now and when we leave. No 50a available to me util we get to the campground on Tuesday afternoon. Will the HydroHot run on diesel on only 110v?

B) How do I tell if I have basement heat? There seems to be on way to tell that I can see.

C) AZSkier mentioned wet bay heater. Is that the mat that I see switches for in the sink area toward the rear? Will that help keep the wet bay from freezing? Will it run on 110v?

kenwyatt · 02-10-2021, 05:24 PM

Forgot to answer your question about heat while driving. My Aquahot heats off the engine when driving. I just set the thermostats to furnace and the temperature I want and drive. Do not put the Aquahot elec or diesel on

Doug427 · 02-10-2021, 05:26 PM

Quote:

Originally Posted by azSkier

Turn on the hydrohot electric and diesel switches as you would for hot water, then use your thermostat to turn on the furnace. Zones 1, 3 and 4 have furnace capabilities. Rooftop heat pumps only work down to 40 degrees, below that, hydrohot and furnace are the only way to stay warm.

I only have two zones (Mountain Aire instead of Essex). Procedure is probably the same. If I understand correctly, in my coach the Hydrohot is both hot water supply AND furnace. There is no stand alone furnace. Will having a 110v line to the coach be enough to run the Hydro Hot on diesel to keep the inside warmed up? Do you have basement heat in your Essex? How wold I tell if I have it?

Doug427 · 02-10-2021, 05:31 PM

Quote:

Originally Posted by kenwyatt

I live in B/CS and this is what I do. Turn on the Elec AND diesel switches. Set the thermostats to about 40. I also turn on my 2 elec baseboard heaters to low. One is in the toilet area and one in the kitchen. Open the cabinet doors. It will heat the water tank area automatically when the temperature gets about 37. I stay plugged into a 50 amp service. Have been doing it for 3 years without a problem. Number is 817-715-0137 if you want to chat about it

Thanks Ken. Looks like it's going down to 16 here in Houston Monday night into Tuesday morning. It'll probably be colder up there in B/CS. I don't think the electric switch in the HydroHot will be an option for me as the only electric I'll be hooked up to will be a 110v line. I'm thinking I'll have to rely on diesel heat only, assuming that will run on only 110V. I don't have any elec baseboard heaters. Worse case I guess I can look for a few small electric heaters to put inside the coach and inside the wet bay to try to keep freezing away.

Doug427 · 02-10-2021, 05:33 PM

Quote:

Originally Posted by kenwyatt

Forgot to answer your question about heat while driving. My Aquahot heats off the engine when driving. I just set the thermostats to furnace and the temperature I want and drive. Do not put the Aquahot elec or diesel on

I hope they all work that way? Hopefully that's enough to keep us toasty while we drive in temperatures in the teens..

Doug427 · 02-10-2021, 05:33 PM

Quote:

Originally Posted by Nildecaf

Don't forget to disconnect, drain and stow your fresh water hose so it doesn't freeze and burst at night.

It's not hooked to water, that shouldn't be an issue, but I'll keep it in mind for when we are. Thanks for the heads up!

Doug427 · 02-10-2021, 05:34 PM

Quote:

Originally Posted by azSkier

Make sure the heater in the wetbay is working. Turn on Zone 3 to get heat to the radiator.

I only have 2 zones. Not sure if the Mountain Aire has a radiator in the wet bay.

96 Wideglide · 02-10-2021, 05:53 PM

My HR never came with a wet bay AH heat exchanger. It was a option, that I guess wasn't ordered.
Possibly Newmar did the same.

n2zon · 02-10-2021, 06:03 PM

Quote:

Originally Posted by Doug427

My coach is a 2005 Mountain Aire 43' with a HydroHot system installed when new. I'm in Houston, and between the warm weather that's typical here and the fact that we both strongly dislike cold weather and never RV in it, I have no idea the capabilities of the Hydro Hot system beyond using it for hot water.. I don't even know how to turn on the heat to heat up the coach. We just keep the unit parked when it's cold outside. Neither of us like cold weather.

Now, we need to use the heat for two reasons - my vacation this year is next week, (the timing was not by choice), and we are heading for Big Bend park, our first trip of any length since we bought the coach last year. It's going to be cold at night in Big Bend, so we're going to be needing the heat. Additionally, there is a deep cold snap coming for a few days and temps are expected to drop into the teens overnight, which is extremely rare down here. I'd hate to winterize the whole coach (I have never done that and have no idea how anyway) when the temps will be dropping on Sun and Mon night and then have to normalize it (is "de-winterize" a word?

) when we leave early on Tuesday morning. My local repair guy says that he thinks the Hydro Hot unit is designed to heat the basement and wet compartments as well as the inside, and if I just leave the heat on for a couple of days during the short abnormal cold snap until we leave everything should be fine.

Do any of you guys who are familiar with this type of coach or heating system know if that is in fact correct? Does the HydroHot system actually heat the basement and wet bay as well as the coach interior? I also noticed that located by the rear sink there are switches for some type of heat pads. I assume these pads in the wet area? I don't have access to 50a where I park, all I have is a 15a or 20a 110v plug. Will that be enough to run the Hydro Heat in diesel mode? What about those pad switches - should I do something with them? Will they also work on the same 110V along concurrently with the heater? How would you guys handle all this?

Lastly, it's going to be cold on the drive out there. First stop along the way will be San Antonio (Bourne, actually) for a couple of days. How do I use the heat just to keep us warm while driving? Do I have to run the generator while driving for the heat to work like we do with the A/C units? I guess I just run the heat like we do the A/C - put the two thermostats in heat mode and set the temp? We have two Dometic DuoTherm thermostats. Is there more than one heat mode on the thermostat and in the heating system, like electric or diesel? I would prefer to run it in diesel mode while we drive if possible. I know the hot water part of the HydroHot system can be run in electric mode or on diesel, we use electric when hooked up at a campground, and it works surprisingly well in electric mode. It's just the two of us and both of us take average to longer length showers, and we've never run out of hot water in electric mode. I'm not sure if the heat is dual mode as well.

Any and all tips and advice you guys can lend would be greatly appreciated. We have zero cold weather experience in this coach (or any for that matter). We just don't like cold weather and when it's cold, which is anything below 50 here in Houston for us, we just stay home.

I just had a full and complete service done on the coach - oil, filters, fuel filters on gen and engine, and had the whole Hydro Hot system serviced. We did a complete punchlist service on the entire coach fixing absolutely every little item that was wrong, and also I also did a full service myself on the Jeep Liberty we're towing. We pick it up on Friday from the repair center and we hit the road on Tuesday at 6AM. This cold snap was the last thing we needed to complicate things, but it is what it is.

I don't have a Newmar, but I do have an AquaHot system.

First, your system will keep the coach more than warm enough to keep anything from freezing. We should have single-digit temperatures here in a day or two, and it would probably keep us comfortable if we were in the coach. (Maybe I'd have to put on a sweater. Maybe.)

Second, 120V power is fine for running the system. It will run happily on 12V for a few days even if you're not plugged in as long as your house batteries are in good shape. It does not take a lot of power.

Third, it will work while driving the coach whether you have the "motoraid" loop or not. If you have it, the engine will heat the coach. If you don't, the boiler burner will heat the coach. Either way, turn on the burner on the Hyrdrohot (aka AquatHot) control panels, set the thermostats to "furnace," and drive. Note: If you have the motoraid loop you also have all or almost all the bits and pieces needed for engine preheat. You want to have that, so ask if you don't know.

Fourth, whether it heats the wet bay depends on what Newmar did. I find it very unlikely that they did not devote a zone to the wet bay. The documentation for your coach should tell you. Or, you can call Newmar and ask. Ours heats the wet bay, but not the entire basement. If that's important to you, check! It could be the case that one thermostat must be set to control the wet bay zone, or not. In ours, there is a completely separate thermostat for the wet bay, with fixed settings and no display.

HTH,