The answer, before the detail
On a Black+Decker ES microwave, no heat with everything else working is one of the few faults where the honest answer is that there is little to check at home. Run the two-minute water test to confirm it, rule out a power-level setting and a door that is not quite closing, and then book it. The cabinet is never opened by an owner, on any model. On the ES models the check that decides the order below is which build you have: a glass turntable, or not.
What you observe on these models
- The turntable turns and the food stays cold — Confirm with a cup of water rather than with a plate of food.
- Food needs twice as long as before — Time the same task you have done for years — that comparison is the measurement.
- The sound of the machine has changed — Worth noting for the technician, but not something to investigate further at home.
- Settings that were changed and not changed back — The cheapest possible explanation and worth ten seconds before anything else.
- The door does not close quite cleanly — An interlock partially engaged can leave the oven running without heating.
- NEAR MISS — nothing happens at all when you press start — That is a machine that will not start, which is a different page from one that runs without heating.
Most likely first on this family
- The magnetron or another high-voltage component — It ranks first while also being the one cause an owner may do nothing about. The fan, the light and the turntable all run from a different supply, which is why they carry on working.
- The door is not closing fully, or an interlock is partly engaged — Second in the practical order, because a door that needs a push can leave the oven running without the part that heats being enabled.
- A power level, defrost or demo setting — It rises in any household where the panel gets pressed by more than one person.
- Grease-blocked filters or a vent tripping a thermal cut-out — Mid-list and specific to machines mounted over a range, where filters loaded with grease make the oven run hot and cut out.
- The control board or the relay that enables the heat — It comes last as the remaining possibility rather than the likely one.
Check in this order, and why
- Heat a cup of water and see what happens — Use a microwave-safe mug and never run the oven empty.
- Reset the oven to full power and retry — Ten seconds, and it is the only cause here you can actually fix.
- Check that the door latches cleanly — A door that needs a push may be leaving an interlock partly engaged.
- Slide out the filters and look at them — They wash in hot soapy water and go back damp-dry.
Power off first
Safety
Never open the cabinet of a microwave oven. The high-voltage capacitor inside can hold a lethal charge long after the machine is unplugged, and nothing behind that cover is an owner part on any model. Unplug the oven before cleaning anything, leave every door interlock exactly as it is, and do not run the oven empty.
Where the owner job ends
Call as soon as the power level, the door and the filters are ruled out — that is the whole owner-side list on this fault. The cabinet is never opened by an owner because the capacitor inside can hold a lethal charge after the plug is out, so there is no further step to take at home.
Other faults covered for the ES models
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
