Our house is 18 mo old. Have just noticed water standing in heat run at front only. We have had a lot of rain, but not too unusual. Contracter claims water table is up and takes no responsibility at this point. We are on a slab, on a lake and our property slopes down toward the lake. Our contractor did not put drainage tile in because he said we had a natural swale. Is this a common problem? The water is now drained away. Are the ducts the problem or the foundation or the drainage??

I assume you have in slab duct heat.
This is done so the ducts will heat the slab during the colder months and create a warm floor. A very common method of installing heat.
Most homes come with a warranty on water intrusion. Check with your paperwork. Living near a lake,ocean or anywhere for that matter should not matter if the job was done correctly.

Many years ago we installed a duct system in a condo complex in which the ducts were placed under the slab. The site was built up from a swamp area before there were folks that worried about frogs and such otherwise they would never had built there. What happend was during the wet months the ducts would fill with water to a point that the heat was cut off because of the blockage. We ended up cutting the ducts off in the wall where they came down into the slab area and put in wall grills. The disadvantage to this was the floor became cooler and we had complaints. As we were the heating contractor on this site the builder pushed off this issue to us. Being new in the business we were stupid and accepted this. Now being in business many years later, I have learned that this was not supposed to happen if the contractor installed the proper exteior drainage system on the outside of the foundation footing area.
Because your on a slab you still need water proofing and Damp proofing done. A lot of builders fail to do this thinking that its not needed because you have no basement. Your current issue proves them wrong.
I suggest that before they start modifying the ducts, that you speak to your lawyer that handled your purchase. Have him or her review your home warranty to see what is needed to get the builder to honor it. Do not play nice guy with him. He will tell you a load of garbage that will sound correct, but in essense only gets him off the hook to redo the job correctly.

The fault lies with the builder not the HVAC contractor.

Thanks so much for your reply. We are going to pursue it with our builder.