Be warned on 'outdoor stoves'. When I was still in high school; my uncle purchased a fabricated boiler, and put it in his basement. This boiler had 'stainless' tubes and fabrication. Seven years later, that boiler was gone. The lifetime warranty expired when the manufacturer, Riteway, went bankrupt. I live today a few miles from several 'outdoor stove' manufacturers. They all remind me of used car lots with a tent for an office. They all talk about 'lifetime warranty' and 'stainless steel'. When I was installing boilers; I would not even touch a fabricated boiler. I saw more than one retube job ruined by a stuck damper motor or an owner that was not qualified to start a campfire. Outdoor stove owners were told to call the original installer. I passed up many begging people when furnaces rotted or pipe melted. I like to sleep at night.
Todays 'outdoor stoves' and 'outdoor heaters' are not boilers. They are designed to not hold or create pressure. They do not have an ASME certification. Many insurance companies will deny claim if one of these non-code heaters is on the premises. Get something in writing from your insurance carrier before you start. The word of an insurance agent is not worth the breath he would expend, after you file a claim. That little ASME cloverleaf plate means that the unit is at least halfway safe.
If a solid fuel heater manufacturer uses, or recommends, plastic pipe or line voltage solenoid pull relays ANYWHERE in their products or systems, run like hell. The best plastic pipe will melt if the temperatures exceed the thermal limit. For most PVC based pipe, the maximum temperature is 150 to 165 intermittant. Even below the maximum temperatures, the pipe will harden and degrade rapidly. If power is interrupted the water temps may rise to boiling, even if the damper limit units drop. When the pump comes back on your pipe is doomed when boiling water hits it.
The old timers understood the difference between iron and steel. They made household stationary boilers from iron and fabricated portable boilers from steel. If a stationary boiler was too large to cast, they used plate that was more iron than steel. They also understood that someone qualified was there to maintain things. Fabricated boilers were made to be repaired and it was understood that high temperatures destroyed steel by embrittlement and warp. Low boiler temps caused acid and made the best steel rot like paper. Boilers were designed to be repaired and regular maintenance was expected. Pipe was meant to take temperatures triple the maximum boiler theoretical runaway. Many even frowned on solder with soild fuel systems and power stokers.
I do not install boilers anymore and I have no money to make. Think about that when some sales weasel starts talking about his product. Is there any real technical information on their website? Is his warranty backed by a third party? What happens when, not if, something 'sticks'? My household boiler is cast and it has been static tested to 175psi. I have two seperate popoff valves that blow at 30 psi. The draw rods will pull at 90 psi and dump the water in the firebox. My auto draft is not electric and it has a fusible link, volitile cutoff, and weight on the draft. The boiler room is solid concrete with a ten inch concrete roof. The circulating system is a choke thermosyphon but I have a two inch high velocity pump to engage into a floor thermal sink if the boiler reaches 200 degrees. I trust nothing when it comes to my life. I sleep like the dead when it comes to the furnace. I still look at the furnace, just before I turn in. End of rant.........