Outdoor wood boiler and Tankless water boiler

[Jayheartswoodheat]

Hello! New here and looking for help in my home outdoor boiler idea.

I am looking to install an outdoor boiler and currently have a Tekagi tankless water boiler.

I have plenty of wood around me and don't like having to pay someone to ship in my heating fuel...

Is it possible to run an outdoor wood boiler with a tankless (Tekagi) boiler system?

Can I use a heat exchanger to transfer the heat from outside boiler water to the lines that feed baseboard from tankless beater boiler unit?

 

[E Yoder]

I would normally use a flat plate heat exchanger to transfer heat from the outdoor boiler to the water before it enters the tankless water heater.
Basically an on demand heater feeding into an on demand heater in series. Most on demand heaters won't run if it's already hot.
If that setup throws some kind of code you could bypass the tankless heater and run them in parallel, with another circulator, check valves, thermostat, etc. There's more than one possible way to do it.
I posted a reply before I noticed you were heating with it, not just doing domestic water.

 

[maple1]

Not familiar with your Takagi, but I think my answer is yes.

 

[Highbeam]

I think the Takagi is a water heater designed for heating cold domestic supply water to 120. Modulating, flow activated. Usually not “heater rated” like a much more expensive boiler and doesn’t include electronics for thermostat activation or pump activation.

Lots of people use a wood boiler and a fossil fuel or electric water heater as backup.