Hastings Borough Council, which took action against the landlord, said a fine totalling £726 was issued by the courts after the landlord pleaded guilty.
A gas safety certificate is required by law for rented properties.
Cllr Andy Batsford, lead for housing at Hastings Borough Council, said: “Ensuring rented accommodation across the borough is fit for purpose and safe is a priority for our council.
“The vast majority of landlords provide exceptional accommodation and go above and beyond to make the necessary improvements to their properties.
“Sadly, in this case this landlord did not comply with the law and failed to work with the council.
“To ensure the tenant’s safety the council took the necessary action. This saw the landlord taken to court where they were issued with a fine following a guilty plea.”