How To Fix A Doorbell

Has your postman ever had to shout through your letterbox because your doorbell is broken? Or have you missed important deliveries because you didn’t know they were there ringing the doorbell for you to answer!? This common inconvenience is relatively easy to fix if you have the time.
Doorbell circuits are not powered by 220-volt grid voltage, but by a lower voltage so that the doorbell button is not dangerous to us. The voltage is kept low by a small 220/12 volt transformer. This transformer is usually plugged into the electrical panel at home and can be disconnected from the grid with a switch.

The main reasons that doorbells may malfunction are:

  • Degradation or failure of the external button
  • Ring failure
  • Transformer failure
  • Accidental interruption or deterioration of the system

If you are experiencing an issue with your doorbell then each of these elements must be checked to identify where the problem lies so that you can solve it.

Things you will need

Step 1: Clean the external button

This may be a single button or it could be inserted into a panel with other buttons for other housing units. In any case, screws secure it to the box containing the power cables. After disconnecting the mains switch of the electrical system at home, open the button panel by unscrewing the screws to check the components. Use a vacuum to remove any foreign objects such as insects or insect nests. If you notice any moisture, you should dry it thoroughly.

how to fix a broken 1

Step 2: Check and perform maintenance on the button terminals

Check the terminals into which the two cables are inserted. One or both may have been removed from the terminals. Loosen the screws and remove the cables. Then spray WD-40® Specialist® Fast Drying Electrical Contact Cleaner Spray on the terminals and cables of the doorbell, which removes condensation and quickly penetrates the hardest to reach areas, drying quickly and leaving no residue. It also restores electrical conductivity. Then reinsert the cables and tighten the terminals. Finally, check that they are working again before closing the button panel.


Step 3: Button operation check

If the doorbell still doesn’t work after carrying out the above method, it may be the actual button that doesn’t work. You can check this by removing the cables from the terminals again and touching their ends together: if the bell rings, the button needs to be replaced (be careful to perform this operation with some caution and respecting all safety measures). If the bell doesn’t ring, reassemble everything and check the transformer that supplies the doorbell with power.


Step 4: Check the doorbell transformer

After turning off the power through the grid switch, access the transformer that supplies power to the doorbell, (usually inserted in the electrical panel of the house). You need to check that the incoming cables (which bring the voltage to 220 volts) or those in output (12 volts) are securely fixed in the terminals. You can also use some WD-40® Specialist® Fast Drying Electrical Contact Cleaner Spray as described above. If the doorbell still doesn’t work, a tester must be used to check if the transformer produces the necessary voltage. However, this step must be carried out with the system live and should only be done by a qualified specialist. The specialist will use the tester to see if the transformer output has the required 12V. If not, the component must be replaced.

controler transformateur sonnette

Step 5: Ring check

If the transformer is also working, but the doorbell still doesn’t ring, the bell is likely to be what is broken. With the voltage disconnected, make sure that the cables connected to it are inserted in the terminals. Again, disconnect and reconnect them after applying some WD-40® Specialist® Fast Drying Electric Contact Cleaner spray. If this step doesn’t solve the problem, ask the specialist to use the tester to check that the voltage reaches the bell itself when the doorbell button is pressed. If it does, the bell must be replaced.


Step 6: System check

If, on the other hand, the voltage is not present, then the problem is along the doorbell system. If this is the case, you’ll need a specialised technician. They will need to investigate the issue and it may involve making disconnections and reconnections in junction boxes and carrying out tests using the tester with the system live. These are all operations which regulations prohibit a private user from carrying out.


Find more DIY Tips & Tricks

Now that you know how to troubleshoot and fix a broken doorbell, why not learn how to remove bath sealant, learn more about the uses for WD-40 or how to get chewing gum out of the carpet.

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