The answer to 'when to replace emergency HVAC service' is that you should typically replace your HVAC system's emergency service components every 10-15 years, or sooner if they are showing signs of wear and tear. The emergency components, such as the thermostat, control board, and safety switches, play a critical role in ensuring your HVAC system functions properly and safely during power outages or other emergencies.
Regular maintenance and inspections by a qualified HVAC technician can help extend the lifespan of your emergency components, but eventually they will need to be replaced. Signs that it's time to replace the emergency service include frequent malfunctions, inconsistent temperature regulation, and increased energy bills.