Author Topic: Cold weather questions  (Read 827 times)

Jerry Emert

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Cold weather questions
« on: November 09, 2025, 12:24:46 PM »
First excuse my newbie like questions. I’ve owned this coach since 2014 and I’m proud to say I’ve avoided freezing weather…until now!  Looks like I will have two days of freezing weather before I can get back to Florida.
A couple days ago the charger function and the 115 pass through section have quit working so I’m depending on an outside 30 amp charger to keep the house batteries charged because the inverter function still works. I’ve tried the hard reset with neg results so it’s beyond my capability at this time. My furnace (hydohot) has never worked even though I’ve had it repaired at least 3 times in the last 11 years.
I have a couple of space heaters to keep the coach warm. I also have a very small space heater in the water tank area. All plugged into extension cords
That’s my sad story now the newbie questions. My biggest concern is the hydro hot. With the electric heating and or the diesel side turned on can the Hydrohot freeze? My logic brain says no but my Florida man allergy to cold says better check with the experts.
Thanks in advance.
Jerry
What other big concerns would you have?
Jerry, Chief USN Retired
2003 Patriot Thunder Lexington 40' 3 Slides
C-12 Ser#  2KS89983
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David T. Richelderfer

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Re: Cold weather questions
« Reply #1 on: November 09, 2025, 02:33:12 PM »
A couple of questions:
1. How cold is the freezing weather and what is the expected wind speed hitting the coach?
2. What kind of pass-through charger does your coach have - BIRD/Big Boy?
3. What does not work on the HydroHot - diesel burner, electric element, or both, or is something else not working?

My comments to:
1. A few degrees below freezing for a few hours, like overnight, especially without wind, is not a problem.  A few space heaters would do the trick.  Otherwise, 5 to 10+ degrees below freezing for more than overnight is a problem.
2. Our Big Boy was acting up a few years ago.  My nephew and I removed it, opened it up and cleaned it thoroughly, put new di-electric grease in it, and it has worked well since.  Last year, I found the two 12v engine batteries low.  We reset the BIRD by turning it OFF and back ON to fix that problem.  I was told BIRD modules are notoriously problematic.
3. Our AquaHot has been a problem over the years too.  I have replaced the igniter module a couple of times, the controller a couple of times, the electric element once, etc.  Three years ago, the technician replaced the controller... and that did not fix the problem... which I learned after leaving the area.  Last year, after two years of not igniting the diesel burner, the igniter module was replaced. The AquaHot has since worked flawlessly.

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Fred Brooks

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Re: Cold weather questions
« Reply #2 on: November 09, 2025, 02:54:25 PM »
   Jerry,
 I would agree with David, A hard freeze is 10 degrees below 32 degrees for 10 to 12 hours sustained. If the Hydrohot is not working on diesel or 120 volt electric, here are some considerations. The wabasto heater inside the Hydrohot has a direct path to fresh air directly below the unit. This could cause serious damage to the fresh water coils inside the boiler unit. If you do not intend to repair the Hydrohot, I would turn off circuit breaker #8 and have the unit drained per the owners manual. If just temporary, prop up a pillow to cover the air intake that was previously mentioned and continue to use your space heaters. Enjoy Florida! Fred
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Eric Maclean Co-Admin

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Re: Cold weather questions
« Reply #3 on: November 09, 2025, 09:49:02 PM »
Jerry
All of the above are good ideas to help mitigate the cold weather freezing your hot water loop in the Aquahot/ Hydrohot .
Another method is to keep a small amount water moving through the unit of course that will use water and tank space if not on full hookups.
The only true way to be safe is to winterize the domestic hot water loop in the Aquahot with plumbing antifreeze.

Without winterizing your best bet is to get the electric side of your AquaHot or Hydrohot up and working that will provide the heat needed to keep the hot water loop from freezing.

Eric
1997 Patriot Yorktown
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Eric Maclean Co-Admin

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Re: Cold weather questions
« Reply #4 on: November 09, 2025, 10:01:58 PM »
Jerry
For your inverter charger problem (not charging and no pass through)

1st.  check your 120 volt breakers there should be a 30 amp breaker which provides power to the inverter if the breaker is ok check for power input into the           inverter at the inverter.
2) while your down at the inverter check to see if there is a pop pin type breaker on the side of the inverter that is popped out .

3) inside the inverter there is what is known as a pass through relay ( these relays spend most of there lives in one position or the other and can sometimes get stuck) this is when a good swift hit to the side of the inverter may be all it takes to jar the relay loose and restore normal operation.

Caution : although it may be tempting do not feed power into the output side of the inverter for any reason as this will damage the inverters internal electronics.

Eric
1997 Patriot Yorktown
3126-B
2009 Chevy HHR
Roadmaster falcon tow bar
Demco Air Force one tow brake.
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Jerry Emert

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Re: Cold weather questions
« Reply #5 on: November 10, 2025, 10:15:13 AM »
A couple of questions:
1. How cold is the freezing weather and what is the expected wind speed hitting the coach?
2. What kind of pass-through charger does your coach have - BIRD/Big Boy?
3. What does not work on the HydroHot - diesel burner, electric element, or both, or is something else not working?

My comments to:
1. A few degrees below freezing for a few hours, like overnight, especially without wind, is not a problem.  A few space heaters would do the trick.  Otherwise, 5 to 10+ degrees below freezing for more than overnight is a problem.
2. Our Big Boy was acting up a few years ago.  My nephew and I removed it, opened it up and cleaned it thoroughly, put new di-electric grease in it, and it has worked well since.  Last year, I found the two 12v engine batteries low.  We reset the BIRD by turning it OFF and back ON to fix that problem.  I was told BIRD modules are notoriously problematic.
3. Our AquaHot has been a problem over the years too.  I have replaced the igniter module a couple of times, the controller a couple of times, the electric element once, etc.  Three years ago, the technician replaced the controller... and that did not fix the problem... which I learned after leaving the area.  Last year, after two years of not igniting the diesel burner, the igniter module was replaced. The AquaHot has since worked flawlessly.
Sorry drove all day and passed out.
Looking at about 5 hours below freezing about 30 degrees with low wind.
I’ve never been sure about the relays. I’ve got a big boy and the small black box I recognize as the BIRD system. My 2003 is half Monaco so some things are weird but I’m not a mechanic so I’m not always sure.
The Hydrohot works to heat hot water both on electric and diesel. It just has never worked for long in furnace mode.
The pass through I mentioned was the 115 for the coach when plugged into shore power. I’ve managed to work around that with a battery charger from Walmart.
I’m probably worrying for nothing. I’ve just always seen the posts here and elsewhere about Hydrohots and aquahots freezing and cost thousands to fix.
Thanks again
« Last Edit: November 10, 2025, 10:37:07 AM by Jerry Emert »
Jerry, Chief USN Retired
2003 Patriot Thunder Lexington 40' 3 Slides
C-12 Ser#  2KS89983
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Jerry Emert

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Re: Cold weather questions
« Reply #6 on: November 10, 2025, 10:34:35 AM »
Jerry
For your inverter charger problem (not charging and no pass through)

1st.  check your 120 volt breakers there should be a 30 amp breaker which provides power to the inverter if the breaker is ok check for power input into the           inverter at the inverter.
2) while your down at the inverter check to see if there is a pop pin type breaker on the side of the inverter that is popped out .

3) inside the inverter there is what is known as a pass through relay ( these relays spend most of there lives in one position or the other and can sometimes get stuck) this is when a good swift hit to the side of the inverter may be all it takes to jar the relay loose and restore normal operation.

Caution : although it may be tempting do not feed power into the output side of the inverter for any reason as this will damage the inverters internal electronics.

Eric
Being a retired Navy electronics tech I have a pretty good understanding of the electric systems on the coach except engine related stuff.
I checked the breaker first and it is fine with power on it. My air conditioners work fine for cold and heat pump when plugged into shore power. The second thing I did was reset the little button breaker on the magnum inverter and it pops immediately.
I’m not going to put any power on the output of the inverter. My Walmart charger has been keeping the house batteries charged so it’s been almost normal in the coach. I’ve been running a space heater off a 20 amp extension cord from the power pedestal so we’re not freezing.
Still worried about the Hydrohot but the electric and diesel heat are both working fine.
Thank you
Jerry
Jerry, Chief USN Retired
2003 Patriot Thunder Lexington 40' 3 Slides
C-12 Ser#  2KS89983
4000MH

Eric Maclean Co-Admin

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Re: Cold weather questions
« Reply #7 on: November 10, 2025, 04:20:29 PM »
Jerry
As long as you keep the hydrohot up to temperature you should have hot water and the hot water loop should be ok.
How ever the hydrohot is mounted outside the heated area of the basement the hydrohot and hot water loop inside it should be ok as long as you keep heat
On in the hydrohot but there is still the water lines running to and from the hydrohot in that unheated area under the coach .
As mentioned earlier those water lines should be insulated with foam pipe insulation and they should be ok to 5 or 10* below freezing as long as you have a heat source in the hydrohot.

As for you Magnum inverter it would appear it has an internal short if that pop out breaker trips immediately when reset.
Funny thing about inverters when they are working they generate heat making them a wonderful spot for mice to make nests, these mice often build their nests on top of the inverter and their pee can cause all sorts of issues with the inverter boards ( corrosion, shorts etc.)
You may want to open the inverter up and get a look for burnt components on the boards.

Eric
« Last Edit: November 10, 2025, 04:26:13 PM by Eric Maclean Co-Admin »
1997 Patriot Yorktown
3126-B
2009 Chevy HHR
Roadmaster falcon tow bar
Demco Air Force one tow brake.
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Jerry Emert

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Re: Cold weather questions
« Reply #8 on: Today at 01:28:28 AM »
Jerry
As long as you keep the hydrohot up to temperature you should have hot water and the hot water loop should be ok.
How ever the hydrohot is mounted outside the heated area of the basement the hydrohot and hot water loop inside it should be ok as long as you keep heat
On in the hydrohot but there is still the water lines running to and from the hydrohot in that unheated area under the coach .
As mentioned earlier those water lines should be insulated with foam pipe insulation and they should be ok to 5 or 10* below freezing as long as you have a heat source in the hydrohot.

As for you Magnum inverter it would appear it has an internal short if that pop out breaker trips immediately when reset.
Funny thing about inverters when they are working they generate heat making them a wonderful spot for mice to make nests, these mice often build their nests on top of the inverter and their pee can cause all sorts of issues with the inverter boards ( corrosion, shorts etc.)
You may want to open the inverter up and get a look for burnt components on the boards.

Eric
Thanks. Should have about 5 hours below freezing. Lowest temp predicted is 30f. I have a friend in central Florida who is or was an authorized repair facility for magnum. He still has all the parts to fix it. Just one more night to worry. By the way, I am due to replace tires this winter. My left rear inside duly reminded me of that by blowing this morning just before noon. Sat for 5 hours waiting for the folks to replace Both drives on that side. Been a hell of a trip home. One more day!
Jerry, Chief USN Retired
2003 Patriot Thunder Lexington 40' 3 Slides
C-12 Ser#  2KS89983
4000MH