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[ARE]

Did a lot of searching and have asked the installer and they are not aware of a single thermostat that can control the OWB with the LP furnance fan and the LP forced air furnace using one controller. So is a person stuck using two side by side. Or what are other options. Searched Honeywell and other main sites, it seems to me there would be a way.

[R W Ohio]

This is what I did.
I installed a SPDT switch in the heating wire from the thermostat (W) to the common termanel of the switch.Then 1 wire to the (W) at the furnace and the third wire from the switch to the (G) at the furnace.With the switch in one position,I will call it gas furnace,the (W) from the thermostat on a call for heat goes through the switch to the (W) at the furnace to start the heating cycle.By changing the position of the switch to the other position,I will call this wood,The voltage now comes from(W)at the thermostat to (G) at the furnace ,and on a demand for heat the Indoor fan relay is energized and the fan will run until there is no more demand from the thermostat.Note that this setup does not give me the back up for the furnace should the OWB not make enough heat to keep the house warm,but I have been running this way for three years with no problems.In September when I start the OWB I turn off the gas valve to the water heater until May when the fire goes out in the OWB. I have not had the gas turned on to the furnace for three years. Another thing that I do is to remove the vent pipes for the water heater and the furnace and cap off the openings in the chimney to keep heat from going outside.

[NC4AB]

Have your installer look at a Honeywell TH8320, it gives you 3 stages of heat control and 2 stages for cooling. 

I have mine set up as follows:

1st stage heating = OWB
2nd stage heating / cooling = heat pump
3rd stage heating = LP gas furnace

In order to make it totally idiot proof you will need to add a relay that is controlled by the cooling select wire (I forget the color) that breaks the power going to the 1st stage heating (OWB) so that when the thermostat switches to cooling the OWB is turned off.  Otherwise just turn the OWB off when you need cooling.

[ARE]

Thanks, sounds like the Honeywell would work great. I would have the OWB off anyway if I had the air on. Not knowing exactly what they ment about the different stages, I wasn't sure when they were describing this that it was the same things. Much appreciated!

[parkinspot]

I realize that this post has been dormant for a while but if I figured that some may be hooking up a new install this season and looking for an answer to this.  I posted another solution to this problem on a different thread that will give you automatic back-up and though I would include it here as well.

http://outdoorwoodfurnaceinfo.com/forum/index.php?topic=616.0