Installed an HVAC system in my house. He didnt have the gas pressure regulated correctly. So it kept tripping the roll out switch. So he decided it would be ok to just bypass the switch. He came to my house at least 4 times to try and get this unit working. Finally had to call another company to have them come look at it. They said that since he had bypassed the switch it caused damage to the heat-exchanger. Now we have to pay to have that replaced. It took the new technician less than 30 minutes to test the pressure and find out it was set wrong. Very disappointed....This has literally taken 2 years to get fixed. Last winter we had to buy electric heaters to help supplement the other HVAC unit.