Flat iron not heating up: causes and fixes

Quick checklist

Work through these in order. Most of the time one of the first three solves it.

1. 1

   Plug the iron directly into a different wall outlet. Skip power strips and extension cords.

2. 2

   In a bathroom, look for a GFCI outlet with test and reset buttons. Press reset if it has tripped, and check whether other outlets on that circuit are dead too.

3. 3

   Switch the iron off, wait a few seconds and switch it on again to clear sleep or auto shut-off.

4. 4

   Look for a lock or hold button that may be blocking the controls.

5. 5

   On a dual voltage iron, check any voltage switch matches your outlet.

6. 6

   Check the cord along its whole length and at the swivel.

7. 7

   Give it the full heat-up time listed in the manual before deciding it is cold.

Note.Stop using the iron and unplug it if you see a damaged cord, sparks, scorch marks or a burning smell. Do not try to open or tape up a hot tool.

Common causes and what they look like

The pattern of the problem helps narrow it down. No lights at all usually means no power. Lights on but no heat often means sleep mode, a lock or an internal fault. Heat that comes and goes often points to a cord problem.

Sleep mode and auto shut-off

Most premium irons switch off on their own after a period of no use. The listings describe 30 minutes for the ghd Platinum+, 10 minutes of sleep for the ghd Chronos styler, and 10 minutes of inactivity for the Dyson Corrale. Some irons also lower their heat when they sense the iron is sitting still. This can look like a fault if you step away mid-style. Switching the iron off and on again usually wakes it.

Cordless irons such as the Dyson Corrale also stop when the battery runs low. Its listing describes up to 30 minutes cord-free and a recharge time of about 70 minutes, and it can also be used corded. If a cordless iron will not heat, charge it fully or use it plugged in, and see Dyson Corrale not holding a charge.

Fuses, voltage and power

In the US, plugs on hair tools do not have a replaceable fuse. In the UK and some other countries, plugs carry a small fuse that can blow, and replacing it with the correct rating is a standard step. Hair tools may also contain an internal thermal fuse or protection device, which is not meant to be replaced by the owner.

Voltage problems are common after travel. A 120 volt only iron plugged into a 230 volt outlet can be damaged even if it worked for a moment. If you use your iron abroad, read how to travel with a flat iron and dual voltage explained.

Brand notes

ghd stylers run at a fixed 365 F (185 C) and signal faults with lights or sounds; read ghd flashing red or beeping if yours is flashing. T3 and BaBylissPRO irons usually have adjustable heat; if one heats but feels cooler than before, check the setting has not been turned down. For curling irons that stop working, see T3 curling iron stopped working.

If your iron heats but hair still does not straighten, the issue may be technique rather than the tool. See hair won't straighten.

When to send it back or replace it

If the iron still will not heat after the checklist, contact the maker or retailer. Several listings we reference mention a 2-year warranty, for example on ghd Curve tools and the ghd Mini, but terms differ by brand, region and seller. Have your receipt and model number ready, and stop using a tool with a damaged cord. See hair tool warranties for what usually applies.

If you need a replacement, our best flat irons list compares fixed and adjustable heat options, and the best hair straighteners guide includes cordless and hot air tools.

See our flat iron picks →

Frequently asked questions

Why is my hair straightener not heating up? Most often the outlet, a tripped GFCI, or sleep mode. Try another wall outlet, reset the GFCI, and switch the iron off and on. Then check the cord and any lock or voltage switch.

Why did my ghd straighteners stop working? A ghd that shows no light is usually not getting power. One that flashes or beeps has likely detected a fault. Check the outlet and cord, restart once, and contact ghd if it repeats.

Can I fix a flat iron that stopped heating? You can fix power and setting problems yourself. Internal faults and damaged cords should go to the maker; opening a hot tool can be a shock and fire risk.

Is it safe to use a flat iron with a damaged cord? No. Unplug it and stop using it. A damaged cord can overheat or expose live wires.