Electric Heater Turns On However Lacks Heat

During the cold winter months, nothing is more frustrating than an electric heater that turns on but fails to provide any warmth. Though a chilly house may have you shivering and yearning for a quick fix, troubleshooting the underlying issue requires patience and care. Let's examine the most common reasons why an electric heater powers on yet lacks heat.

Check Power Supply and Connections

Before inspecting the heating unit itself, we must ensure electricity is flowing properly. Verify the outlet has power by plugging in a lamp or other appliance. Check circuit breakers and reset any that have tripped. Note if breakers trip repeatedly, as this may indicate a short or overload on the circuit.

With power confirmed, check the heater's plug and cord for damage. Frayed wires or loose prongs can disrupt power flow. Use an electrical tester to check for voltage at the outlet while the unit is on. No voltage indicates a wiring issue. Inspect connections within the heater as well. Loose or corroded connectors prevent proper power transfer to heating components.

Inspect the Heating Element

Electric heaters generate warmth through heating elements--metal wiring that grows hot when electricity flows through. Poor contact, gaps, or breaks in these wires disrupt heating. First, check for visual signs of damage like deformities or burn marks. Then use a multimeter to test element continuity. Simply set the meter to continuity mode and touch the probe pins to each end of the element. A continuous beep indicates solid connections. No sound means the element has an internal break.

For older heaters with irreplaceable elements, a metal clamp can temporarily repair small gaps. But for most modern units, replace damaged heating elements. Follow instructions to detach bad components and install new ones. Ensure replacement parts match the heating capacity and dimensions of the original.

Examine the Thermostat

A faulty thermostat prevents an electric heater from reaching operating temperature. Thermostats act like an engine throttle, regulating energy flow to maintain a certain heat level. Defective stats may fail to call for heat, or get stuck at one temperature. Test functionality by raising the thermostat setting significantly higher than room temp. If the heater still doesn't generate heat, the issue likely lies with the thermostat.

Check thermostat wiring for loose connection points. Severed wires can mimic a bad stat. The thermistor, which senses ambient temperature, may also need replacement. If adjusting the stat appears to work intermittently, the temperature dial mechanism itself may be damaged. Replacing the entire thermostat is usually simplest. Take care to choose a replacement properly rated for the heater's voltage and wattage.

Clean or Replace the Fan

While electric heating elements create warmth, internal fans distribute hot air into the surrounding space. A seized or blocked fan results in heat building up inside the unit. Check for visual obstructions like dirt, dust, or pet hair restricting fan blade rotation. Use compressed air or a vacuum crevice tool to dislodge debris. The motor mount screws can also loosen over time, allowing the fan to slip and scrape against the housing.

Test fan operation separately from heating elements. Set the heater to fan-only mode, if equipped. If the blades still fail to spin, the issue lies with the fan motor. Binding or worn out motors require replacement. Match the voltage rating and physical dimensions of new fan motors to original specifications. While awaiting a new part, a temporary external fan directed at the heater intake can aid heat distribution.

Fix Igniter and Flame Sensor Issues

Gas-powered convection heaters rely on igniters and flame sensors to safely operate the gas burner. The igniter generates a spark to initially light the gas. The flame sensor confirms ignition succeeded. Issues with either component create problems.

Igniters can wear out over time, firing weak sparks unable to light burners. Replace worn igniters matched to the heater model. Dirty flame sensors can fail to detect a successful ignition, shutting off the gas despite a lit burner. Clean sensors gently with steel wool to remove grime. Bent sensor probes should also be straightened or replaced as needed.

Troubleshoot Safety Features

Modern electric and gas heaters incorporate safety features that disable operation in unsafe conditions. While designed to prevent hazards, tripped safety switches can also render good heaters inoperative. Common safety devices include tip-over switches, high-limit cutoffs, gas valve locks, and flameout sensors.

Tip-over switches disengage power when a heater falls over. High-limit cutoffs trip when internal temps get dangerously high, preventing fires. Flameout sensors cut gas flow if a burner blows out. Check your heater model and reset any of these protections that may have falsely tripped. If issues persist, replacements may be needed. Only use original manufacturer parts to maintain safety integrity.

Consider Control Board Failure

On more advanced electric and gas heaters, circuit boards regulate temperature settings, switches, safety systems, and fan speeds. If troubleshooting other components yields no answers, the logic board itself may be the culprit. Control boards can fail due to power surges, electrical shorts, voltage spikes, and general wear.

Diagnosing control board problems requires an expert. Consider hiring an appliance repair technician to test board voltage inputs and outputs. They can isolate issues and source a replacement as needed. Provide the heater's brand name and model number to ensure getting the proper control board.

Check for Obstructions and Proper Venting

Both electric and gas heaters require open intake and outflow paths to move air. Blockages or restrictions prevent proper airflow, causing heat buildup inside the unit. Check the outer shell and internal air channels for debris like dust, dirt, or pet hair. Use a vacuum hose to dislodge and remove obstructions.

Gas heaters also rely on outdoor exhaust venting to remove combustion byproducts. Inspect the flue pipe and cap for damage or blockages. Snow, nests, or other debris can restrict the exhaust outlet. Also ensure appropriate upward pitch on horizontal vent sections so exhaust moves smoothly.

Preventing indoor heat from escaping is just as crucial as generating it. Damaged or missing seals around doors, windows, attics, basements, and ductwork waste huge energy. Inspect weatherstripping around openings and re-apply caulk or foam as needed. Duct tape works temporarily for small duct leaks.

For permanently sealing ducts, use metal tape and mastic paste. Never ignore major plumes of escaping warmth or the whistling of drafts. The quicker you seal leaks, the faster your heater can regain a comfortable indoor temperature. Consider an energy audit to find hidden gaps.

An electric heater that turns on yet provides no warmth is frustrating, but solvable with methodical troubleshooting. Start by verifying power supply, then inspect internal components like heating elements, thermostats, and fans. Reset safety devices, check control boards, and ensure proper venting. Sealing drafts also aids efficient heating. With patience and care, you can diagnose the true issue and restore cozy warmth.