Ask for the warranty in writing. Many cold-climate systems carry 10-year parts coverage from the manufacturer; labor coverage varies by installer. Ask your installer for their terms.
Parts-only sounds identical on the phone. The invoice is where the difference lives, so ask for the labor answer on paper.
Some coverage quietly halves if a form is not filed after install. Ask who files it and get that answer in the proposal.
If the warranty is real, it survives being printed next to the price. A quote that will not state its coverage is stating it.
Heat Pump Network is not the installer and does not guarantee coverage. The written warranty from the manufacturer and your installer is the document that controls.
Two minutes gets a Nashville estimate with the coverage line printed on every option, so the comparison is honest before anyone is in your house.