With the conditions you explain, sure. Adequate ventilation, combustible offsets, chimney draw, You will be plenty warm with a 130 heating that space, and tied to your existing heating system, no danger of freeze-ups either.
If your old boiler developed a couple leaks, what is the water source you use? Ever tested? Might be worth a shot to send a sample off to the state lab. I assume your old boiler was a steel unit, so if it's 20 years old or more, time up!
The AHS is VERY quiet and will not disturb anyone sleeping close by, and you could get some free hot water if tied in to the system.