Less than half of Canadians trust outside contractors and repairmen to be honest in their home, according to an Angus Reid Public Opinion poll commissioned by Steele on Your Side.

The online survey of 1,006 random Canadians found that 46 per cent of people nationally and 43 per cent in British Columbia believe that the people working in their home are looking out for their best interests.

Sixteen-per-cent of respondents said they have been gouged on repairs, with contractors requesting more than what was quoted in the original estimate.

Three-per-cent said they found out that a contractor did work that was not necessary.

So when the furnace man comes calling and says you need a pricey replacement part how do you know whether to believe him?

Our Steele on Your Side investigation this week revealed questionable tactics used by furnace contractors – and industry problems with repairmen trying to talk customers into expensive and unnecessary repairs.

Heating contractors are in the Better Business Bureau's top 10 when it comes to consumer complaints. It received 98 consumer complaints in 2011 – a 25 per cent increase from the year before.

BBB President Lynda Pasacreta said it breaks her heart to see consumers -- especially seniors and new immigrants -- taken advantage of by shady companies.

'There are a lot of fly-by-nights and bad companies. It's a tough business to be in," she said.

Pasacreta said many of the problems they see with furnace contractors, including inaccurate estimates or unnecessary part replacement, could be avoided by asking a few simple questions.

"Do your due diligence," she said. "You check out the business you want to do with, and get a couple quotes -- and all those different things that we constantly remind people to do whenever you're hiring a contractor."

But not every consumer is doing their homework, according to the Angus Reid Public Opinion poll.

Among the 37 per cent of respondents who had repairs done in their home by an outside contractor over the past five years, only 11 per cent researched the company beforehand on the internet and just nine per cent checked with the BBB.

"This is asking for trouble," said pollster Mario Canseco.

The majority of homeowners found their contractor through a friend (46 per cent), used a contractor who was a friend (18 per cent), or found them in the phone book (13 per cent). Nine per cent said the contractor was the only one available when they needed someone and seven per cent said the contractor was the cheapest.

Pasacreta said sometimes references given through friends and family aren't reliable: "We hear references where 'my brother's friend, uncle recommend that this person come over and fix my furnace.' When you find out they haven't got the proper licensing -- they really don't know anything about fixing the furnace."

The BBB said there are certain steps you can take to protect yourself before you invite a contractor into your home:

Make sure the furnace contractor is licensed with the BC Safety Authority

Ensure they are certified gas fitters

The contractor should be bonded and insured for liability and property damage

Get at least two estimates for the work to be done

Look closely at the warranty – what it covers and why

Also, make sure the furnace contractor offers maintenance and service after installation and after warranties expire.

Of survey respondents who had repairs done, only about a third (35 per cent) said they entered into a written contract before the work began. Only about one-in-four got references from previous customers (27 per cent) or received at least three quotes (26 per cent).

Homeowner Brian Mott got a second opinion after a furnace company quoted him $460 to fix a part. It turned out the fix was unnecessary.

He said he's learned his lesson when it comes to furnace repairs. He has this advice for fellow homeowners: "Be skeptical."

The BBB said it has received reports about fraudulent contractors going door-to-door trying to frighten homeowners into agreeing to new furnace systems.

Consumers should know that direct sales contracts can be cancelled for any reason within 10 days after the homeowner receives a copy of the contract.

Angus Reid Public Opinion conducted an online survey on January 6 and 7 among 1,006 randomly selected Canadian adults. The margin of error—which measures sampling variability—is +/- 3.1%.

Watch CTV for the full report from Lynda Steele, and more tips about how to protect yourself from unscrupulous contractors….