Ed Pawlowski wrote:

"J. Cameron Davis" wrote in message
news:T9Tsl.603150$yE1.530961@attbi_s21...
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.

The furnace/heating company may have an idea to clean the ducts, but not for
fixing the real problem. First step is to find and stop the source of the
water. Check gutters and downspouts to be sure rain is not getting under
the slab. Could snow near the house be clocking the water from running off?
Next is to drain the ducts. Can you get a hose in there and pump the water
out?

Do you have any water or drain pipes running in the same area? Years ago
copper pipe was sometimes run under the floor and over the years, it
corrodes from chemical reaction with the concrete.

Ask a neighbor if they know a contractor or a handyman type that may be able
to help. You may need a waterproofing specialist too.

Someone with an inspection camera should be able to inspect the existing
ducting to determine the extent of the problem.

It might be possible to use the existing ducts as a chase to fish new
smaller high velocity ducts that would be continuous and sealed
eliminating the water issues.

There may be a liner product that can be installed in the existing ducts
to re-seal them. Products like this exist for re-lining utility water
and sewer pipelines.