My house is a 2 bedroom ranch style build in 1953. It sits on a concrete
slab - no basement or crawl space. The air ducts for the furnace are down in
the slab. The house has a rectangular shape, and the furnace is at one end.
Water is getting into the air ducts. The floor vents for the half of the
house closest to the furnace work and have air coming out. The floor vents
in the half of the house furthest from the furnace have no air coming out,
and when the furnace runs I can hear water gurgling. There is also a damp
scent coming from those vents. Apparently, they are blocked by water. There
was no problem with the HVAC system last night, but there is this morning.
We had rain yesterday and overnight.

What do I do? There is no way to find the place where water is getting in
without demolishing the slab. I suppose new vents could be run over the
ceiling, but I still have to deal with the water. I'm very concerned that
it's going to back up into the house. Even if the old vents are taken out of
commission the leaks still have to be fixed somehow. What do I do? Who do I
call? A furnace company? A general contractor? This sounds like it could
cost a fortune to fix. Any advice will be greatly appreciated. I'm really in
over my head and have no idea what to do. But, I've got to do something soon
before the house floods.