Here to stay, or living on borrowed time?

We are in the midst of researching and getting quotes on upgrading our heating system and hot water heater.
One of our options includes a hydronic forced air heat system which would replace the radiators found under just about every window in the house with ductwork. The big benefit of this system is that when you install the ductwork and air handler you’re more than halfway to a central A/C system. That feature can be added as budget allows. The old radiators do seem to put out decent heat, and quickly, but they do pose some decorating and furniture placement hazards. It hasn’t been too hot yet, but I think it’s a safe bet that they don’t provide much cooling in the summer.
We are all about the Rinnai tankless hot water system and according to one plumber I met with certain units can actually provide the hot water needed for the radiators if we want to do that first before the expense of installing the ductwork. The ultimate system will include a Rinnai Tankless water heater which will provide domestic hot water and hot water for the Rinnai hydronic furnace, which includes the air handler. The hydronic furnace is supposed to be a much less dry heat than a typical gas fired or heat pump based furnace, so you theoretically avoid the dried out noses and static commonly associated with those systems. A lot of this is relatively new technology, but not totally untested and we’re excited to be early adopters and use a more efficient technology for our heating and hot water, and it also takes up considerably less space in the basement than the ancient oil burner. The Tankless unit mounts on the wall, and the air handler/furnace and ductwork will be in the attic, allowing more room in the basement for storage and workshop use.

Rinnai R75LSi