No cause for the St-Hubert Street fire has been confirmed, but there had been attempts to thaw frozen pipes in the building, before the fire broke out.
In a notice issued Wednesday, Montreal firefighters said electrical thawing was being suspended "as a preventative measure."
"When in doubt, we're not taking any chances," said Martin Farmer, with the Montreal firefighters.
The electrical method works by sending an electrical charge into a frozen pipe so that it heats up. The worry is that in older buildings, the electrical charge might be somehow shorting out electrical panels and causing fires, according to Farmer.
Generally, private contractors such as electricians and plumbers are carrying out the work.
He could not say how many fires are under investigation to determine if electrical thawing was a cause.
Electrical thawing of pipes will resume once the risk of fire has been eliminated.
The use of steam to thaw pipes will still be allowed.