The risk of carbon monoxide poisoning is due to a shifting of water heater components during transit. This shift may cause an air filter door switch to stop functioning properly. If the air filter door is not in proper place and the switch fails, the water heater could possibly continue operating. If dust and lint build up there is a risk of carbon monoxide poisoning.
The tankless water heaters affected are indoor models of the Power Vent 199,900 BTUH. The heaters have piping on the top and bottom of the unit, a cream or grey jacket enclosure and were sold between May, 2004, and December, 2006, for $800-$1,300. Approximately 42,200 tankless water heaters are affected by the recall.
Tankless water heaters work on an "on-demand" basis, meaning that water is heated only when used, rather than sitting in a tank and maintaining a preset temperature all day. However, tankless water heaters use more air for ignition so they must be properly vented and have a proper air supply.
If you have a recalled water heater, stop using it immediately if the air filter door is out of place. Contact the Rheem Manufacturing Company or the installer to arrange for a free, on-site heater repair.
One of the best things you can do to prevent carbon monoxide poisoning, even if you do not have a tankless water heater, is have carbon monoxide alarms installed outside all sleeping areas and at least one on every level in your home. Mild exposure to carbon monoxide causes symptoms similar to the flu, however higher levels of exposure can cause headaches, vomiting, nausea, confusion, and dizziness. In extreme cases of carbon monoxide poisoning the person can pass out and stop breathing.
Carbon monoxide poisoning can lead to death. If you suspect you have been exposed to carbon monoxide, seek medical attention immediately, where professionals can perform a blood test to see if you have carbon monoxide poisoning.