A homeowner contracted for chimney repair for a water heater, and the company came out and made some repairs to the water heater and its exhaust pipe and vent.
Several months later, when they had another maintenance issue, a different contractor discovered that the vent from the water heater was not up to code. The way it was installed, wind could cause carbon monoxide to fail to vent and back up into the home. This was because the first contractor had put in a new vent pipe at an inappropriate angle, performing a repair that was not up to code. The new contractor fixed the problem with the vent.
How can they get a refund from the company that created the problem? Can they sue the contractor for creating dangerous conditions in their home?