Ask questions about your installation
Give each provider the same information: household hot-water use, existing heater, proposed room, photographs, and any electrical or remodeling plans. Ask which models they support and why a particular model fits.
PNNL's installation checklist covers manufacturer instructions, clearances, drainage, startup checks, and explaining maintenance to the homeowner. Heat-pump water-heater installation checklist.
Ask the installer to show how its quote addresses those tasks. Ask who evaluates air supply, winter room conditions, hot-water delivery, electrical supply, and any related plumbing work. A question about the actual home is more useful than asking how many heaters the company has sold.
Check support before buying
Ask how the installer obtains manufacturer technical help, orders approved parts, and handles a fault it cannot resolve. Request the service contact and any visit or diagnostic charge terms. A manufacturer directory can help identify candidates, but confirm the provider actually handles the selected water-heater model and the requested work.
Ask for relevant local installation examples or references that the provider is permitted to share. Listen for an explanation of a difficult site condition and how it was resolved. A photograph alone cannot establish the quality of work or a customer's satisfaction.
Compare the complete project
Request written inclusions for equipment, removal, electrical work, drainage, permits, other trades, and startup verification. Name who coordinates each dependency and any work excluded from the price.
For care and warranty, separate manufacturer parts coverage from labor, visits, and any service agreement. Ask who receives the first call when hot water stops and whether another provider is needed for electrical or household plumbing work.
Your next step is to send the same site brief to suitable providers and compare their answers, scope, and support arrangements. An installer who can explain the fit and handoffs gives you a stronger basis for choosing than a confident sales answer.