Three rooftop A/C's

[Rick Daniels]

I have several of the original manuals for my MH including the Beaver and Magnum manuals.  My MH has three rooftop A/C's and all of the manuals I have indicate two rooftops.  Also, I have viewed several other Beavers of the same year and model as mine online and they only have two A/C's. Am I to assume that the third A/C is an add on? My thermostat has four zones.  Don't know what the fourth zone is for but zones 1,2 and 3 are the rooftop A/C's, #1 being the rear and continues forward.  Any tips on what zone 4 is for would be helpful. 
My coach is a 1999 Marquis Jasper 40', single super slide out.

[Mike Groves]

Certainly different than mine.  Mine has up to 4 zones but only 3 are used for the heat and only 2 are used for cooling.  Yours obviously does have the extra one for cooling and I would imagine it must have been an option.  My zones are 1 - front 2 - bedroom 3-bathroom for heat and 1 - front and 2 - bath and bedroom for cool 3- does nothing in cooling mode. 

Mike

[David T. Richelderfer]

In my coach the 4th zone is for basement heat.  The basement #4 zone is not controlled by a thermostat in the living quarters.  The other three zones are my living quarters - #1: living room, #2: bathroom, #3: bedroom.  My coach has one thermostat in the living room that controls heating (three furnaces) and cooling (the fore a/c) in the living room and kitchen, and another thermostat in the bedroom that controls zones #2 and #3 heating (one furnace in the bathroom and one furnace in the bedroom) and cooling (the mid a/c in the bathroom, and the aft a/c in the bedroom).  My understanding is there is a basement thermostat that is preset to keep the basement from getting too cold.

[Russ Taylor]

On my 2001 PT I thought I had a third AC unit, it was in fact my Satellite TV antenna.   It looks very similar to my AC units. 

[Rick Daniels]

I also have a trac-vision sat TV antenna.  I did find a small numbered dial behind the panel in the water service bay which I assumed was the pre-set thermostat for the basement.  I am heated with a Hurricane unit.  Hard to imagine there is zone control for the heat but could be.  It's cold at night here in Montana so I am going to fire up the system and start turning things on and off.  I was told once that only one zone needed to be set for heat which would send the Hurricane heat throughout the coach, assuming the two valves in the engine compartment are turned in the proper direction.  Each register has its own high/low rocker switch which seems to only control the fan speed.  Much  bigger learning curve than I expected but what else do I have to do.

[Joel Weiss]

I also have a trac-vision sat TV antenna.  I did find a small numbered dial behind the panel in the water service bay which I assumed was the pre-set thermostat for the basement.  I am heated with a Hurricane unit.  Hard to imagine there is zone control for the heat but could be.  It's cold at night here in Montana so I am going to fire up the system and start turning things on and off.  I was told once that only one zone needed to be set for heat which would send the Hurricane heat throughout the coach, assuming the two valves in the engine compartment are turned in the proper direction.  Each register has its own high/low rocker switch which seems to only control the fan speed.  Much  bigger learning curve than I expected but what else do I have to do.

The typical Hurricane installation has two heating zones in the living areas and one for the basement.  In addition, there is an aquastat that will light the Hurricane if the water exiting the water heater is less than the set temperature.

Unlike an Aquahot, a Hurricane uses a single liquid loop through all registers and the water heater.   The two thermostat zones control the heat register fans (High, Low, Off).  The master switch for the Hurricane is usually on a kitchen cabinet.  I believe there is a Hurricane manual posted in the BAC's document files.  If not, I have one I can provide.

When you say that turning on one of the Hurricane zones will send the heat throughout the MH, you are technically correct, but unless the register fans in the other portion of the coach have been turned on by the appropriate thermostat you will get no benefit of the heat in that portion of the MH.

I have become pretty knowledgeable about the operation and maintenance of Hurricane systems.  Kevin Lambert at ITR in Vancouver WA is a great resource and he, essentially, rebuilt mine completely last spring.  Feel free to ask questions if you have any.

[Mike Groves]

I am heated with a Hurricane unit.  Hard to imagine there is zone control for the heat but could be.  It's cold at night here in Montana so I am going to fire up the system and start turning things on and off.  I was told once that only one zone needed to be set for heat which would send the Hurricane heat throughout the coach, assuming the two valves in the engine compartment are turned in the proper direction.  Each register has its own high/low rocker switch which seems to only control the fan speed.  Much  bigger learning curve than I expected but what else do I have to do.

Rick,

I think, like me, you only have 1 LOOP so yes, if at least one zone is calling for heat, the loop pump will energize, however, the fans will not turn on at each heat exchanger unit unless the thermostat is set for that "zone".

You do have zone control from your thermostat up front.  If no one has replaced the thermostat then yours would be like mine probably.  So, to change zone, press the top two buttons simultaneously (unit has 4 buttons), and you should see the zone numbers change.  I don't know if mine was simply mis-wired originally so that Zone 3 is the bathroom heater and Zone 2 is the bedroom heater, or since I only have 2 cool zones Beaver did it this way on purpose.  I do know that when I had the hurricane replaced with the Oasis Combi, the guys at ITR told me they fixed the zones but I found out later they only moved the thermostat wires so that the thermostat in the bedroom was now controlling the bathroom heater and vice versa which I then corrected after noticing at night with the bedroom door closed that the bathroom heater never shut off.

Anyway, nice to have more 1999 Marquis' represented on the forum.

Mike

[Rick Daniels]

Thanks Mike and Joel.  My system is as both of you have said.  With your information I went on a mission and turned things on and off and everything seems to work OK.  I have only one thermostat and it is in the living area.  I have yet to locate the basement heat source but I will keep looking.  I do have a Hurricane manual but it did not address the four zone thermostat.  At least I now have heat and know how to regulate it.  THANK YOU

[Mike Groves]

My bathroom has a white sensor in it and so does the bedroom.  Those sensors are connected to the single thermostat as inputs for zones 3 and 2 in my '99.  Pretty sure you'll see those white sensors in your bath and bedrooms.  Look on the left wall of the bathroom as you exit the bathroom to the bedroom and on the driver side cabinets in the rear of the bedroom.

Mike

[Joel Weiss]

From this discussion it's evident that the PT's were fitted with multiple single-zone thermostats rather than the multi-zone one in the Marquis.

As for the basement heater, I know that mine is hidden in the wet bay along with the holding tanks.  I'm not sure if there's another one by the fresh water tank.