Xcel Energy made progress Monday in restoring its natural gas operations to normal, though more than 800 businesses across four states still had their service shut off after a big pipeline explosion Saturday in ­Canada.

The businesses, however, are part of a special Xcel rate program. It allows the utility to cut gas supplies in times of need, in return for lower commercial rates the rest of the year. Partici­pants are supposed to have backup fuel supplies.

Just as a brutal cold wave descended on Xcel’s customers, the company’s gas system was stressed by the explosion of a TransCanada-owned pipeline south of Winnipeg.

In order to conserve gas, Minneapolis-based Xcel on Saturday asked residential customers throughout its system to voluntarily dial down their thermostats to around 60 degrees. The more the heat got turned down, the stronger the gas pressure would be throughout Xcel’s entire system, lessening the likelihood that customers would suffer outages, the company explained.

By Monday morning, the gas flow from TransCanada’s pipeline into Xcel’s system had improved. Xcel began lifting calls for voluntary conservation, particularly notifying 100,000 customers in the areas most at risk: eastern North Dakota, northwestern and central Minnesota and western Wisconsin. The conservation appeal was completely lifted by noon Monday.

“We know keeping [customers’] homes at 60 degrees for nearly two days in this extremely cold weather was uncomfortable,” Kent Larson, Xcel Energy’s senior vice president of operations, said in a statement. “But the effort was worth it, and it helped us maintain the system so no one experienced outages.”

No residential customers had their service interrupted, Xcel said, nor did businesses, except those in Xcel’s Interruptible Gas Rates program.

That program curtails gas to participating customers, usually when temperatures sink below 5 degrees, in return for lower year-round rates. All of the program’s participants — nearly 800 businesses in Minnesota and North Dakota and 250 more in Wisconsin and the Upper Peninsula of Michigan — were affected.

The North Dakota Mill, a flour mill in Grand Forks, was one of them. When Xcel mandated a gas curtailment, it switched to propane to fuel its boilers. While propane itself is a scarce and expensive commodity these days, its use is expected to be temporary for Xcel customers like North Dakota Mill.

“We were able to switch over to the backup and not lose any time,” said Vance Taylor, the mill’s president and general manager.