Toxic fumes from a faulty buy to let gas boiler killed one tenant and led to two other people suffering carbon monoxide poisoning.
A judge heard that the boiler had not been checked for four years and had already been labelled as dangerous by an engineer but was reconnected by the tenant.
Landlord Victoria Martindale pleaded guilty to seven gas safety offences at Derby Crown Court and was sentenced to 16 months in jail suspended for two years. She must also perform 200 hours community service and was fined £4,000 and ordered to £17,500 costs.
The court heard Stephen Newton, 51, was found dead in the house by friends on his 51st birthday.
His partner and a neighbour were treated for carbon monoxide poisoning, but made a full recovery.
Martindale told the court she managed the rented home herself and failed to carry out safety checks or service the boiler for four years.
Meanwhile, a gas engineer had condemned the boiler as dangerous after visiting the property to fit a new gas meter.
The supplier wrote to the landlord about the danger, but the tenant did not pass on the letter.
Instead he reconnected the supply due to a lack of other heating at the property.
Speaking after the hearing, Health & Safety Executive Inspector Noelle Walker said: “This was a tragic incident and came very close to being a double fatality. It was a stroke of good fortune that friends came to call and Mr Newton’s partner managed to escape with her life.
“Ms Martindale completely failed in her responsibilities as a landlord. She should have taken all reasonable steps to ensure the property’s gas fittings and flues were checked for safety every year, maintained in a safe condition and that gas boiler was properly serviced.
“Landlords must have all installation, maintenance and safety checks carried out by a Gas Safe registered engineer. Tenants should not use an appliance they have reason to believe is unsafe and should never carry out any gas work themselves.”
The HSE says 10 people die of carbon monoxide poisoning from faulty gas fittings every year.