A solar hot water checklist should cover your household’s hot water use, available roof space, roof condition, orientation, shading and whether a booster is needed during cloudy periods. Check that the system suits your climate, existing plumbing and hot water requirements, and compare its estimated running costs, warranty, maintenance needs and noise levels. Use an appropriately licensed installer and confirm they can handle any required electrical or plumbing work. Rebate and certificate eligibility varies by location, system and household circumstances, so check the current rules with your state or territory government and energy.gov.au.