Alan Knight, 51, admitted murdering David Bond, 50, in Worthing and was sentenced at Hove Crown Court to serve at least 19 years.
After the hearing, Sussex Police said the killing in August followed a row over the cleanliness of the house in Osmonde Close where they both lived.
Det Ch Insp Tanya Jones said the tipping point was the microwave oven.
Describing the level of violence as "horrendous", she said: "His reaction was extreme for something, which in reality, was very small."
Police said Mr Bond was last seen on 6 August in The Warwick pub, but an argument began after he arrived home.
Knight texted his friend to say his landlord had asked him to move out. He wrote: "Shall I just kill him and you find me somewhere to duck till we get a plan..."
Police said he later messaged the friend to say he was "only joking" but then sent six images of Mr Bond's body, which she did not believe.
The next day, Knight drove Mr Bond's car to Hove and withdrew Â£600 before abandoning the car in London and visiting a friend in Southend.
The friend later told Essex Police she believed he had killed his landlord.
Shortly afterwards, Sussex Police went to Mr Bond's house where his body had been seen.
Det Ch Insp Jones said Knight knew what he was doing and described it as "a cold and calculated crime". She said the pair only lived together for about six months.
In a statement, Mr Bond's family said: "David was a caring loving son and father to his two sons, David Jr and Christopher. Out of no reason, his life was taken away cruelly."
A lodger has been jailed for life for stabbing his landlord 29 times after a row about cleanliness.