You really do need to have a proper heat loss calculation (CSA F280 standard for Canada) performed on you house to see what capacity boiler you really need, which should neither be undersized nor oversized and should be the highest efficiency possible (over 90% efficient).

What size and efficiency boiler are you replacing? Do you want an all-in-one integrated unit, radiant heat and full capacity instantaneous domestic tankless hot water? What type radiators do you presently have, large cast iron, baseboard cast iron, aluminum plate with copper tube? What water temperature water is required? How do you air-condition?

I would suggest finding an experienced, accredited hydronic installer in your area.

SR

Here is a link that might be useful: Beautiful Heat (Canada)

I am thinking of replacing my 60,000 btu "Bryant" Gas fired furnace with the same 60,000 BTU "RINNAI Hydronic Furnace" heated by hot water.

My Real Question : I am worrying that this RINNAI Hydronic Furnace is not reliable, sometimes no heat or not enough heat; not consistent heating etc...

Anybody has installed this RINNAI Hydronic Furnace with GOOD User Experience?????

Thanks a lot for the great help!!!

They are a matched pair. The AH is designed by Rinnai to operate with the Rinnai water heater and provide both heat and dhw. There is a dhw priority switch, but I'm not sure if that is an option or standard.

I represented Rinnai in my business for over 20 years. They make excellent equipment. That type system is very popular in the Toronto area.

Hi! We are doing the same thing now and wondering if you had the system installed and how you feel about it.