WE have a 12 year old Hot water tank that is brand new. Can it be converted to propane and if so how? This tank was donated to a project for a new home that burned down due to a fire so the house is all rebuilt but we got 2 hot water tanks. One N/G and another propane. We need both to work if possible.

Yes the tank can be converted. My suggestion is to contact a Propane dealer that does installations and have the tank converted.

Orifices have to be re-sized to compensate for the differences between Natural and Propane gases.

: A.O. SMITH WILL ONLY ALLOW THE CONVERSION OF GAS WATER HEATERS FROM LP GAS (PROPANE) TO
NATURAL GAS. THE CONVERSION OF A GAS WATER HEATER FROM NATURAL GAS TO LP GAS (PROPANE) IS
NOT ALLOWED UNDER ANY CIRCUMSTANCES.. . I also checked the Rheem site, and on a page titled "Conversion Instructions-Natural Gas To LP Gas" found detailed instructions which included: NOTICE: The parts required to make this conversion are
Supplied in a bag attached to the water heater. Should
Your heater not have this bag attached to the water
Heater, a replacement can be obtained. Simply contact
The manufacturer at the address below and request a
Replacement conversion kit..
Having said that they do make conversion kits,(see image) check them out at; Google Image Result for http://www.a1poolparts.com/stores/a/A1PoolParts/catalog/hayconversion_thumb.jpg (http://images.google.com/imgres?imgurl=http://www.a1poolparts.com/stores/a/A1PoolParts/catalog/hayconversion_thumb.jpg&imgrefurl=http://www.a1poolparts.com/-strse-Heaters--dsh--Accessories/Categories.bok&usg=__YlD0TQlTmrMP7OHPYsZc2VrgfJ8=&h=143&w=131&sz=6&hl=en&start=21&sig2=s3khF4h9fmhBKiIkjHzaMQ&tbnid=rg4et5BOeLRZQM:&tbnh=94&tbnw=86&prev=/images%3Fq%3Dnatural%2Bgas%2Bto%2Bpropane%2Bwater% 2Bheater%2Bconversion%2Bkit%26ndsp%3D20%26hl%3Den% 26rls%3DGGLM,GGLM:2009-22,GGLM:en%26sa%3DN%26start%3D20&ei=sEwySuiXE-GgmAeUgdGdCg)
Good luck, Tom

My son does gas work on both Natural and Propane gas.

It is a very common request to convert from Natural to Propane.