Any person that owns or operates an OWHH shall not use a fuel other than the following: I. Clean wood; II. Wood pellets made from clean wood; III. Home heating oil, natural gas, or propane that complies with all applicable sulfur limits and is used as a starter or supplemental fuel for dual-fired OWHHs; or IV. Other fuels as approved by the commissioner through rules adopted pursuant to RSA 541-A.