Boe said the company is consolidating all of its heating product work in its non-unionized Minnesota plant.
The Winnipeg factory is expected to close by the end of this year.
"They had a meeting and they told our members, 'Well, we made $8 million but, you know, we're moving this," Leslie McNabb of the Steelworkers Union, which represents the Winnipeg employees, told CBC News on Thursday.
"One of the members said, 'Why do they have to rub it in our face?'"
Operated in Winnipeg since 1920s
Boe said the closure has nothing to do with the fact the Winnipeg plant is unionized, nor is it related to the cost of production in Canada.
The company's engineering operations are already in Minnesota, so the move made sense, Boe said.
McNabb said Phillips and Temro Industries has operated a plant in Winnipeg under one name or another since the 1920s.
McNabb estimates that about 90 per cent of the plant's workers are women.
"Some of them have been have been there over 30 years," she said.
"Now the company's just, 'Yeah, we can make more profit down there. We're getting a grant from government there. We're moving.'"
Some firms blame Canadian dollar
Winnipeg has lost about 750 manufacturing jobs in the past year with the closure of Aveos Fleet Performance, an aircraft maintenance company, and as biotech firm Cangene reduced its workforce.
Dave Saur, president of the Winnipeg Labour Council, said the job losses in the city are adding up, with companies often blaming the high Canadian dollar during contract talks.
"What are we going to be able to do here at the bargaining table to try and mitigate that?" he said.
"At some point it does come where the company decides to just shut down the facility, and I think you have that example right now with Phillips and Temro."
Saur said he worries about the future of the manufacturing industry in Winnipeg.
But Jim Carr of the the Manitoba Business Council said these kinds of layoffs are cyclical.