Ignoring water heater maintenance. Your water heater is under constant assault from Las Vegas hard water, accumulating sediment every day. Without annual flushing, that sediment reduces efficiency by up to 29% and can shorten the unit’s lifespan by 2–4 years. Most homeowners don’t think about their water heater until it fails — and by then, it’s a $1,500–$3,000+ emergency replacement instead of a $150 maintenance visit.