A woman called emergency services when she discovered her house full of smoke at approximately 2pm on Tuesday.
Two appliances and a tanker from the Whanganui Fire Brigade attended the scene on the No 3 Line between Kaimatira Rd and Valley Rd
"We had a heat transfer kit that overheated and caused a lot of smoke in the house," station officer Shane Dudley said.
"The lady at the house turned off the power to the unit and we got in and pulled it out."
Dudley said electrical faults occur from time to time and in this instance he was not sure what caused the kit to overheat, but it would be investigated.