Rinnai Contiuum for radiant heat

Could be done

But why? Just curious. Why not use a wall hung gas condensing boiler? I don't believe you would get the federal tax credit as the instantaneous is a water heater and you are not using it in a water heater application. Plus, with the boiler you wouldn't need the heat exchanger. How would you reset the radiant with the tankless? With the boiler is has out-door reset, ie comfort and eff for the customer.