In Colorado, your HOA and Property Management company are legally obligated to maintain the property in a manner that does not unnecessarily endanger residents or disrupt essential services. In your case, if the HOA and property manager insist on replacing a functioning steam boiler during the colder months, they may risk exposing residents to significant hazards, such as frozen pipes or safety issues. On the other hand, they may perceive a risk of the unit failing or other damage occurring if they do not replace the boiler.
To protect yourself, document your concerns in writing and formally communicate them to the HOA and property manager. Explain the risks involved and request a delay until spring when the replacement can be safely managed. Ultimately, however, if the boiler is their property and responsibility they can proceed unless you sought and obtained an injunction. If they proceed without adequately addressing your concerns and damages occur, such as frozen pipes, liability is likely to rest with the HOA or Property Management, not with you. This is particularly true if they failed to act reasonably to mitigate foreseeable harm.