Yesterday, our heating company guys came to the house to get the boiler revved up and cleaned for our Chicago winter. we have a 1951 radiant heat system. A few years ago, we had a leak, had the floor jackhammered (nightmare!), fixed the leak, and kept our fingers crossed. Yesterday, the guys said the water pressure was zero, so there appears to be another leak. The guys said that once the system starts leaking, chances are other leaks will show up. They're coming back Monday with a tool that "listens" for leaks. My thought is that it's time to find another system. I'd like to have some suggestions. We have an attic, no basement., exterior is brick, well-insulated, triple-pane glass throughout, gas fueled boiler., house is under 1300 square feet. I don't want to have the floor jackhammered again. Also, house is on the market. I want to put in a system that works, not just patch up a leak and smile at a homebuyer; I want to have a system installed that I can believe in but doesn't cost us a fortune, since we won't be here to enjoy it. Any advice?? (Why not ask my heating guys? I will of course, but extra knowledge from people who aren't trying to sell us something would be very nice. Thanks.)

It sounds like you have old metal pipes in a slab that are beginning to fail. Actually, I am surprised that your system operated as long as it did without failing. Nowadays, PEX is used in lieu of metal pipes and should last much longer. If you want to totally eliminate future problems, it seems like it might be time to abandon the radiant heat system entirely. Perhaps consider an alternative mini split heating/cooling solution. However, the lowest cost solution for you might be to just repair the most recent failure and disclose the situation to new buyer.

you could also switch to hydronic baseboard heat, but I have a feeling that the labor cost in your neck of the woods would make that a pricy choice

Is the system zoned? Perhaps a combination of a heat pump and the zones that don't leak. Or a radiant ceiling or wall in the area that leaks.

Baseboard is probably the best bet.