An energy consultant in Halifax says while owning a heat pump can cut heating bills in half for homeowners, he cautions that the installation process can cause problems.

Art Irwin of Irwin Energy Consulting Services says unlike homebuilding, which has a specific code and is subject to inspection, a heat pump only requires a certified electrician.

"You're at the mercy of the installer," said Art Irwin of Irwin Energy Consulting Services.

"In the last 10 years, it's been a big explosion in the sales of those things," he said, adding that there should be more regulations around installation and quality assurance.

Irwin says some contractors may be certified by the manufacturer, which can be a two to three-hour installation workshop.

Jack Knox, general manager of Halifax Heating Residential, calls it an "underground economy," with very little to no control over who can purchase the heat pumps.

Knox estimates the pumps can deliver heat at a third of the cost of other heating methods because heat is transferred from outdoors, instead of generating it indoors.

Heat pumps are "unbelievably popular in Nova Scotia," according to Donald Dodge, Business Development Officer for Efficiency Nova Scotia. He said the organization cancelled its rebate program for homeowners in 2011 because they didn't need incentives.

"The numbers were astronomical. We had gone from something like 3,000 heat pumps a year to selling close to 20,000," he said.

Tips for homeowners

1. Get more than one quote

Ask many questions to get a clear understanding about on offer, and remember the lowest quote is not always the best.

"Understand what you're getting and whom you're getting it from," said Knox, offering the age-old advice, "If it's too good to be true, it probably is."

2. Ask for and check references

Knox suggests asking for at least three references. Some questions he suggests:

Did the contractor perform like they agreed to? Did they show up on time? Did they do the work they said they should do? Were they knowledgeable? Were there any issues you couldn't work out with the contractor? How well does the system work?

Knox also advises checking with the Better Business Bureau and Nova Scotia Power.

3. Confirm the contractor's credentials

Nova Scotia Power says to make sure their contractor has a Red Seal refrigeration card for the heat pump and a Red Seal electrical certification card for the electrical connection.

Knox says many people aren't aware that homeowners are personally liable if an employee gets hurt on their property and is not properly licensed or insured. Irwin recommends ensuring a potential contractor has liability insurance and worker's compensation coverage.

4. Compare the heat pump to others

Nova Scotia Power suggests researching and fully understanding the heat pump's warranty.

5. Don't pay more than 25 per cent of the total cost up front

Irwin says this if a contractor is looking for a lot of money in advance, it's can be a sign their credit is poor and they owe money to a lot of suppliers.