The brigade is also asking for all new schools to be fitted with the systems to help cut the number of fires.
Between 2001 and 2005 there were 1,725 school fires in London. Last year, there were 239 non-accidental fires in the capital's schools.
An insurance company spokesman said that investment in the systems could be repaid in recouped premiums within eight years.
The campaign is targeting local press, broadcasters and online media.