Murray McKinnon, who worked with Mr Peachey for five years, described him as an MP who "worked hard to ensure his constituents were treated fairly".
"Nothing was too difficult or unable to be solved."
He said Mr Peachey's two passions were his family and his electorate and he was extremely proud of achieving a 17,000 majority in the last election.
A good friend, who also spoke at the service, said that even after Mr Peachey became ill, his constituents remained a top priority, and despite not being able to drive he got someone else to take him to see a 92-year-old who had a complaint that needed dealing with.
"That was the type of person Allan was."
He said Mr Peachey referred to his wife, Jeanette, as an "angel" and was incredibly proud of his children Bevan, Cameron, Leanna and Gemma.
Speaking on behalf of his siblings, Bevan described his father as "the world's greatest dad" and a man who was always there for each of them, not matter what.
"He was the first port of call and he always had the right answer. He was always available, even if he had to duck out of a meeting.
"Outside of family life we were so proud of what dad achieved."
Foreign Minister Murray McCully, who delayed his trip to Hawaii for Apec to attend the service, first got to know Mr Peachey when he was Rangitoto College's principal and made "frequent and rather forceful representations" to local MPs.
"To describe Allan Peachey as outspoken would be a serious understatement.
"As I got to know him I began to understand why - he had an absolute conviction about the power of education to change people's lives."
Mr McCully said that Mr Peachey, as an MP, would have had days where Parliament and politics would have been deeply frustrating.
"He was a man who felt an unshaking belief in old-fashioned concepts like integrity, hard work, excellence and merit," said Mr McCully.
Rangitoto College associate principal Don Hastie said Mr Peachey was a "visible principal" who had a no-nonsense approach to discipline, often telling students "if a teacher asks you to do something, do it with a smile on your face".
He grew the school to the point it became the largest in the country and believed "his students' success was his success, their failures were his failures, too".
Rangitoto College students formed a guard of honour outside the church yesterday as Mr Peachey's body was driven away.
Allan Peachey
* Born Wanganui, October 18, 1949.
* Died, surrounded by his wife and four children, November 6, 2011.
* Former head of NZ's largest high school, Rangitoto College.
* National MP for Tamaki.