John Casey stole from pensioners in Sandwell, Birmingham, Coventry, and other parts of the country.
He would also pose as a water board or council worker, and on August 4 last year, he targeted a 75 year-old woman in Smethwick.
Casey claimed he was there to fix the boiler but took a bag containing £60.
Police today described him as 'cruel and calculated', as they revealed how the 52-year-old was finally caught.
Victims regularly referred to the con man as 'beer-bellied', and police established that the same thief was using a silver Rover 45 in different crimes.
They traced it to Casey, and he was arrested in July.
He gave no comment in police interview, but eventually pleaded guilty after being confronted with CCTV and DNA evidence.
Casey also admitted kidnap and attempted robbery after he took a man in his 70s to a cash point in Ealing, London, to draw out money.
The victim became suspicious and fought back when he tried to grab the money, and Casey fled with nothing.
He admitted nine burglaries worth a total of more than £1,800, which happened between 2013 and April this year.
Five of them happened this year.
Casey, of Heathside Drive, Kings Norton, was sentenced to nine years and three months at Birmingham Crown Court on Monday.
Dc Kate Watts, from West Midlands Police Force CID, said: “This was cruel and calculated deception which targeted vulnerable people in our society.
“They allowed him into their homes believing he was someone they could trust; but he took advantage of this for his own financial gain.
“It was clear from the descriptions we received from victims that this wasn’t a legitimate police officer and thorough investigation work enabled us to identify Casey as the prime suspect.
“We always encourage people to check for identification if somebody knocks on the door to say they’re on official business.
“Check it carefully and phone the organisation they claim to be from. Get a number from the phone book or online - don’t use any number they provide on a card."