Cargo Bay or Tank Heating ??

[Jack W Hannah]

Still trying to get totally familiar w/our 2002 Patriot and wondering if there is any heat source for the Cargo Bays and/or the tanks of our coach.

The only info I can find in the manual or literature mentions that the doors are insulated.

Any input on this would be appreciated.

Thanks

[David T. Richelderfer]

I am not overly familiar with your Beaver model but I believe, generally, all Beavers have a basement heater (radiator/fan) that gets its heat from the heated coolant provided by the Aquahot or Hurricane heating systems.  This basement heater is located on the front wall of the basement compartment housing the waste tanks... inside the basement access door on the streetside just ahead of the dual axle.

Our coach is a 2004 Beaver Marquis with a diesel-burning Aquahot.  Our coach has four heating zones, each with one or several heaters (radiator/fans).  Our living room/kitchen (zone 1) has three separate heaters, the bathroom (zone 2) has one heater, the bedroom (zone 3) has one heater, and the basement (zone 4) has one heater in the area of the waste tanks.  The basement heater has a non-adjustable thermostat and all the heaters get their heat from the Aquahot.  But, of course, the Aquahot must have either the diesel/propane burner ON, and/or the 120vac electric element ON, and/or the coach engine must be ON.

Again, the heat is not generated at these heaters.  Their heat is provided by coolant hoses coming from and returning to the Aquahot where the coolant is heated.

[Fred Brooks]

   Jack,
The water bay compartment is controlled by the thermostat that is responsible for the bathroom heat exchangers. When that zone is activated, it also includes the holding tank area. The fixed thermostat inside that area is set for approximately 45 degrees. It is not likely you will get any heat in that area until it is below 28 degrees for several days. If you want to manually activate to check it do the following: remove the carpeted cover that accesses the holding tanks. Turn on your aqua hot. Turn on the thermostat to "furnace" that heats the bathroom and turn it up to 90 degrees. Locate the fixed thermostat inside the hoding tank compartment and put an ice cube against it. Watch the heat exchanger muffin fan and it will come on. Fred

[Jack W Hannah]

Fred - Thank you for this most informative response. My coach is currently in the shop but next time I'm there I'll certainly check in to your suggestion.

[Dan Johnson]

Not to take over this thread but I have a question either one of you might answer. I just bought a 2002 marquis. I noticed the # 2 pump was running all the time at my storage when the aqua hot was shut down  with temperature at 35.  Is the pump getting power from the basement thermostat 24/7?

[Fred Brooks]

    Dan'
Check both your thermostats and zones that they are not set for furnace. Especially the bathroom because that zone calls for heat in the tanks area and blows thru a register into the storage compartments. Fred

[Dan Johnson]

I figured out part of the issue. I found the thermostat in the water bay. When the temperature gets below about 42 degrees it closes activating the number 2 aquahot pump. But no heater fan so I assume I have to have the bathroom-bedroom thermostat turned up?

[Eric Maclean]

Dan
If the tank bay thermostat calls for heat the fan in the tank bay should run along with the circulation pump .
Check at the Aquahot for the relay that the tank bay thermostat controls to turn on the circ pump depending on the system the older units used a double relay that controlled the fans and pump both when a thermostat called for heat.
 I've had a couple of them that got dirty contacts and have had good luck at removing the top from them and cleaning the contacts.
Here's a link with a picture of what they look like.


https://secure.aquahot.com/ProductInfo/ELX-W1A-486.aspx

Hope this helps
Eric

[Eric Maclean]

Dan
The only Aquahot wiring diagram I could find is under the 1996 Patriot and my be different than your 2002 Marquis
But I. The 1996 Patriot wiring diagrams on page 59 .
It shows the bay heat wired straight from the fuse panel to the bay thermostat which directly feeds power to the heat exchanger fan and by way of a blocking diode sends power back to the Aqua hot relay where it activates the pump.
After looking closely at my unit it appears that they did not control a relay with it at all and opted to piggy back onto another pump control wire and that is why they used the diode to keep the other zones from running the tank bay system by back feeding it.
The earlier systems only had one circulation pump for all the zones the setup was such that any thermostat would run the pump but each zone used its own relay to control its own zone fans.

As Fred stated by 2002 the system wiring could be different but either way when the thermostat calls for heat the fan should run
If you can access the bay fan I'd check for power to the fan when the bay thermostat calls for heat you may find the fans has failed from running all winter in storage.
Hope this helps
Eric

[Dan Johnson]

Eric
Thanks for the reply. As soon as this cold snap takes off I will start looking. If the fan is bad I have no idea how I am going to replace it. It is behind drain and all the other pipes.
Dan

[Steve Huber Co-Admin]

Dan,
What model Aqua Hot do you have in your coach?
Steve

[Dan Johnson]

I have AHE-100-02S

[Eric Maclean]

Dan
The heat exchanger and fan are usually mounted behind the wer wall in the wet bay which means removing the wet wall enough to access the heat exchanger .
The wet wall is usually held in place with trim and screws and once it is loose there is enough slack in the plumbing to allow it to move out a foot or so a d it can be tipped forward to gain access to the tanks and other prices in the bay.

Hope this helps
Eric

[Eric Maclean]

Dan
When I put my coach in cold storage the only way I've found to shut down the bay heat and circulation pump is to remove the B fuse.

If you look at the schematic on page 76 of the Aquahot manual for 100-02s. In the coach assist library you will see how the bay heat is wired.

Eric

[Steve Huber Co-Admin]

To follow up on Eric's post, access the AHE-100-02S Service Manual. In Coach Assist select the Aqua Hot, Hydro Hot Manuals Library and then your AQH model. It's in the discontinued models section. Page 76 shows the wiring diagram. Assuming I'm reading it correctly, since the zone 2 pump and the bay fan both get power from the relay output, and the pump runs, you either have a bad or stuck fan, an open diode or a bad connection. Suggest you check for 12v at the fan when the pump is running.
Steve