Well I’m an HVAC Technician and the heat exchanger is not a material defect. Those happen all the time. That’s why you get annual check ups on those items.
As for the radon, if it is reading high then maybe something is wrong with it and possibly installed wrong.
Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas.Wikipedia
Symbol: RnAtomic number: 86 Electron configuration: [Xe] 4f145d106s26p6 Did you know: While other estimates might be higher or lower, there is general agreement that radon exposure is the second leading cause of lung cancer after active smoking and the leading cause among non-smokers. nih.gov.. (Heat exchange it is a little bit easy fix but both together not really a good mix) so the answer to your question is yes. Either replace the furnace or get it repair furnace/boiler license personnel.
@Mindy Jensen It's going to depend on your state's RE laws as to what must be disclosed, but my bet is yes, it is.
In MA, we must disclose latent (hidden) defects that we know about - but states differ in their regulations.
This is one reason that seller's agents around here typically don't want to see the home inspection report. Once they know every little nit-picky thing that the inspector pointed out, they need to disclose them.
Radon is relatively cheap and easy to remediate. Expect to spend under $1,000. It's just a fancy exhaust fan that pumps basement air out and up through a PVC pipe going up the side of the home.
I agree with @Charlie MacPherson . Once you know it, you are potentially liable.
Colorado law considers "anything that could impact a buyer's value or desirability of a property to potential purchasers" as material, which is a pretty broad description.
In my opinion, the potential liability isn't worth not disclosing. You're better off addressing it and resolving it. You can also disclose it and decline to fix it.
@Mindy Jensen , when in doubt disclose disclose disclose! Not disclosing is what opens a seller up to potential liability. If they disclose they are well covered.
If it is about the condition of the house and the seller's are concerned it could affect a sale, that is a good indication that its something that should be disclosed.
@Mindy Jensen since a cracked heat exchanger and radon are both potentially dangerous then yes, they become an item that must be disclosed. However, that only affects future buyers. What about your buyers? Are they proposing the seller remedy in some way? Are you still within the inspection objection timelines?
Radon is a natural byproduct of many construction materials and from the ground. Poorly ventilated areas are prone to build up of radon. Get a fan for the crawl space and open the windows in the house, get it retested and it will most likely disappear from the report.
But best to just get the fan installed so it keeps the radon at bay