When we had our old addition rebuilt a few months ago, our mitigation system was turned off so we weren’t working in exiting fumes. The new addition’s roof is now higher than the old one so the exhaust pipe is now about 6 inches below the roof line. The code inspector said the pipe should be extended above the roof line but in the meantime the system is now making a loud humming noise that we can hear when we are outside or our windows are open. We think there is something wrong with the fan and called the installer. It was installed about 12 years ago. The installer says that we need a new fan because the system was turned off when our addition was being built, that we are not supposed to turn it off. Without looking at it, he says it will cost me $3000.00 to fix it. Is this correct? I thought I should have someone look at it before I commit and while they are here, have them adjust the exhaust so that it exits above the roof line. Or could the problem just be the exhaust venting below my roof?
Google “radon system exhaust mufflers.” There are about 4 or 5 different manufacturers. You can make one pretty easily for about $25 too. If the noise is coming from vibration against your home rather then air exhaust, try cutting the pvc pipe on both sides of the fan and isolating the fan between a couple rubber boots with hose clamps. Cost $10.
$3000 for a fan? I think there is a misunderstanding somewhere. An entire new system for a large home would be less than $1500 in most cases, probably less. Call another mitigation company…