{"id":13724,"date":"2025-03-19T06:57:40","date_gmt":"2025-03-19T13:57:40","guid":{"rendered":"https:\/\/www.appliancepartspros.com\/b\/?p=13724"},"modified":"2025-03-19T07:46:08","modified_gmt":"2025-03-19T14:46:08","slug":"how-to-identify-and-solve-blinking-light-codes-on-a-furnace","status":"publish","type":"post","link":"https:\/\/www.appliancepartspros.com\/c\/how-to-identify-and-solve-blinking-light-codes-on-a-furnace\/","title":{"rendered":"How to identify and solve blinking light codes on a furnace"},"content":{"rendered":"
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As winter settles in, keeping your furnace in tip-top shape is a must to keep your home warm and cozy. But what do you do when your furnace starts flashing lights or error codes at you? It might seem a bit overwhelming, but decoding these blinking lights isn’t as tricky as it seems. With the right know-how, you can figure out what your furnace is trying to tell you and get things back on track.<\/span><\/p>\n

The info in this article might not match your exact appliance model. While we aim to provide handy advice for all sorts of DIY appliance fixes, different models and setups can mean variations in troubleshooting steps, error codes, parts, and so on. For the most spot-on guidance, we recommend checking the manufacturer’s documentation for your specific model or feel free to <\/span>reach out to us<\/span><\/a> with any questions.<\/span><\/em><\/p>\n\n

What those blinking lights mean<\/span><\/h2>\n

When your furnace starts flashing a light code, think of it as its way of sending an error signal. These codes are designed to help you pinpoint and troubleshoot specific issues. Each blinking pattern corresponds to a particular issue, and by decoding them, you can take the steps needed to sort things out.<\/span><\/p>\n

Read more: <\/b>12 simple space heater safety tips for this winter<\/b><\/a><\/p>\n

Common furnace error codes<\/span><\/h2>\n

1 flash: ignition trouble<\/span><\/h3>\n

A single flash indicates an ignition error or flame failure. This could be due to a dirty or faulty flame sensor, a malfunctioning igniter, or an interruption in the gas supply. The flame sensor’s job is to detect the presence of a flame, and if it’s dirty or bad, it might not register the flame correctly.<\/span><\/p>\n

2 flashes: pressure switch error (stuck closed)<\/span><\/h3>\n

Two flashes point to a pressure switch error where the switch is stuck closed. This might be caused by a short in the pressure switch circuit, a faulty pressure switch, or issues with the draft inducer. The pressure switch makes sure your furnace’s combustion process is safe, so it’s important to tackle this issue promptly.<\/span><\/p>\n

3 flashes: pressure switch error (stuck open)<\/span><\/h3>\n

Three flashes mean the pressure switch is stuck open. This can happen due to blockages in the pressure switch hose, loose or improper hose connections, or wiring issues. Any blockage or disconnection can stop the switch from doing its job right.<\/span><\/p>\n

4 flashes: open high limit<\/span><\/h3>\n

Four flashes indicate an open high limit, which could be caused by dirty air filters, wiring problems, or blockages in the flue. The high-limit switch prevents the furnace from overheating, so if it’s open, it might be a sign that things are running too hot.<\/span><\/p>\n

Read more: <\/b>Your guide to choosing a space heater<\/b><\/a><\/p>\n

Safety first<\/span><\/h2>\n

Safety comes first when working on any appliance. Here are some practical tips to help keep you safe:<\/span><\/p>\n