If there’s already a suitable outlet near the range, you likely won’t need an electrician to install an over-the-range microwave. However, if there isn’t an existing outlet or the current one doesn’t meet the microwave’s power needs, you’ll probably need an electrician to install a new outlet. 

The number of outlets and lights you can safely run on a single circuit depends on the circuit's amperage and local electrical codes. A general rule is to allow one outlet or light fixture per 1.5 amps, keeping the total load under 80% of the circuit breaker's capacity. For example, a 15-amp circuit can typically support up to eight outlets or lights, while a 20-amp circuit can accommodate up to ten. Always consider the combined power usage of all connected devices and fixtures to prevent overloading. For specific guidelines and to ensure safety, it is best to consult local electrical codes or a licensed electrician.

Most standard residential water heaters, which are typically around 40 gallons and use 240 volts and between 3,500 and 5,500 watts, require a 30-amp, two-pole circuit breaker. For smaller, point-of-use water heaters using 120 volts and between 1,500 and 3,000 watts, a 30-amp breaker is also often adequate. However, some models may have different needs; units that use more watts than average may require a 40-amp breaker, while smaller units might only need a 20-amp breaker. Newer, tankless, or more energy-efficient models can also require a higher amperage. Having the correct breaker size is crucial for safe and efficient operation, so it's best to consult a licensed electrician to determine the specific needs of your water heater.

According to the National Electrical Code® (NEC®), the electrical code for kitchen outlets states that electrical outlets in a kitchen should be installed no more than 48 inches apart. This ensures that a receptacle is no further away than 24 inches from any place on the countertop. Countertops wider than 12 inches need an outlet on the wall above the countertop.