The union was founded in 1872 as the Amalgamated Stove, Grate and Kitchen Range Fitters' Protection Society.

[1][2] The union survived, but remained very small for many years with only 360 by the end of the century.

[1] In 1908, the Amalgamated Society of Whitesmiths, Domestic Engineers and General Pipe Fitters and the Birmingham Society of Hot Water and Steam Engineers merged into the union, which changed its name to the National Union of Operative Heating and Domestic Engineers, Whitesmiths and General Iron Workers.

It relocated its head office to Birmingham, and was finally able to claim a membership of more than 1,000 workers.

[1] The Society of Smiths, Fitters, Hot Water and Steam Engineers merged into the union in 1911.