Enbridge Gas, which is the utility serving Durham Region and the GTA, says prices are expected to jump by 20 per cent on July 1.

The average household in Durham spends about $1,400 a year on natural gas for home heating and water, which means the increase will be about $300.

"This is a supply and demand issue," said Enbridge spokeswoman Debbie Boukydis. "This is a direct cost increase that we are passing through to the consumer. We don't make any money from it."

Many factors are creating greater demand for natural gas, such as a push in the United States to build gas plants instead of coal-fired plants and the fact that many big industrial users are switching from oil heating to gas.

Only those who buy natural gas directly from the utility will be affected by this latest hike -- that's about 60 per cent of customers in Durham Region.

Those who buy from a gas marketer like Direct Energy or Universal Energy will continue to pay locked-in, premium prices in exchange for stability over a three- or five-year period.

The new rates for July haven't been approved by the Ontario Energy Board yet but it is expected they will get the green light with no issue, especially because Enbridge gives retroactive credits to customers when prices go down again.

"The good thing is, this is happening in July when most customers aren't using much natural gas," Ms. Boukydis said. "They won't see the change until they turn the furnace on in October."

For those worried about the increase, there is help.

Low-income customers can take advantage of the Winter Warmth program offered by Enbridge. The average household can distribute the price hike throughout the year instead of being hit all at once in the winter, with the company's budget billing plan.

There is also the conservation route.

Customers can cut their natural gas usage by installing a programmable thermostat, upgrading to an energy efficient furnace and other natural gas appliances, replacing the furnace filter regularly and sealing cracks and leaks to keep heat in.

Federal government grants are also available to homeowners who make energy efficient upgrades to their home, up to a maximum of $5,000 per home.

For more information on the ecoENERGY Retrofit for Homes, visit www.oee.nrcan.gc.ca

To learn more about Enbridge and natural gas prices, visit www.egd.enbridge.com