Because we work and live in a vacation resort area, and inspect a lot of condominiums near the beach, the over-the-range microwave receives close attention. It is a vacationers second most-used food prep appliance—after the phone for ordering pizza. Microwaves get a lot of abuse, and don’t have a long lifespan. Also, the replacement units are usually installed by a handyman. So a condo is an enhanced version of the microwave problems we find in a regular residence. Here’s our top 5 typical defects:
1)Does not vent to exterior - Microwaves come out-of-the-box set up to exhaust out the front and the baffle plate has to be adjusted and fan rotated to reconfigure for top or back exhaust, so it blows through a duct to the roof or out an exterior wall. A microwave that has ductwork in place to exhaust cooking fumes to the exterior, but has not been configured to do it by the installer, is a common defect.
2)Not on separate circuit - The building code requires that a microwave which is fastened in place have a separate 20-amp circuit. Depending on the size, they are rated to draw between 8 and 13 amps. Other appliances operated at the same time can overload the circuit if the microwave is on a shared circuit. We test by seeing If the microwave still works when we trip the GFCIs at the countertop or the kitchen appliance breaker(s). It is not uncommon in a remodeled older house to find that the dishwasher and microwave are both on a single countertop appliance circuit.
3)Loose mounting - Even a mounting that is slightly loose is noted because, once it begins to loosen, the mounting deteriorates progressively with usage.
4)Not functional - There are two kinds of “not functional”: a) completely dead, with unresponsive control panel, and b) sounds like it is working but does not heat a test cup of water.
5)Radiation leakage due to damaged door or handle - This is typically only a problem if there is damage to the seal around the door or the handle. We use a digital microwave leakage meter, shown below, and report if the leakage exceeds the 5.0 milliwatt threshold set by the EPA. A recent survey by appliance service technicians found that over half of the microwaves more than two years old have leakage at least 10% higher than 5.0 milliwatts.
A separate issue that is open to interpretation at this time is the height of the bottom of the microwave above the top of the range. The IRC (Interational Residential Code) defers to the manufacturer’s installation instructions regarding the correct distance. All the manufacturer installation manuals we