Normally, it should kick in within five minutes. However, if it takes longer, there might be an issue. While older models might need a bit more time, if your furnace doesn't start
While moisture and rust are one of the most common causes of delayed ignition in furnaces, dust and lint can also accumulate and cause problems. This can be easily remedied by having your furnace inspected and cleaned by professionals before each heating season.
That whole sequence of events that happens takes about 1 minute from the time thermostat tells the furnace to start, to the time the blower turns on and gives you heat through your registers.
If your furnace won't kick on when you turn the thermostat up, it could be due to a variety of reasons such as a tripped circuit breaker, a faulty thermostat, or a problem with the furnace itself like a malfunctioning igniter or gas valve. Checking these components might help you figure out the issue.
It's like bringing a kettle to boil – the heating process doesn't happen instantly. Instead, your heating cycle needs time to get rolling before it starts blowing hot air. After approximately 10-15 minutes, start moving down this list if the furnace heater blowing cold air continues.
Check Your Furnace Air Filter
Next, check your heater's air filter, as this can cause a furnace to stop blowing air. Your filter could be so saturated with dust and debris. In that case, even though the furnace is actually blowing air, your clogged filter is blocking it from making it into your ducts.
Most furnaces kick on and off between three to eight times an hour, depending on things like outdoor air temperatures, the furnace's age, and how much insulation you have. That's why, instead of asking how often a furnace should cycle, it's best to stay alert to changes in how your furnace is running.
At your electrical panel, make sure all switches related to the HVAC system are on. Reset any tripped breakers and replace all blown fuses, and your furnace should kick back on. Gas supply leaks: If you smell gas, leave the area immediately and contact your gas company for emergency services.
Defective Igniter or Pilot Light
If it clicks but your furnace won't ignite after the combustion cycle, the electronic ignition systems probably need to be replaced. In cases where the furnace ignition starts normally but only stays on for a few minutes and then goes out, a new pilot light likely needs to be installed.
A slight delay between turning on your furnace and feeling its warmth is typical. Normally, it should kick in within five minutes. However, if it takes longer, there might be an issue.
The thermostat may have a dead battery, so replace them with fresh ones and try again. Your furnace may turn on right away after this. If it doesn't, you may have a faulty power circuit. Have an HVAC professional diagnose this issue, and provide you with professional recommendations.
The heating system may take longer to warm up due to issues like clogged air filters, thermostat problems, or inadequate maintenance. These factors can hinder proper airflow and heat distribution in the HVAC system, leading to delays in reaching the desired temperature.
If your heater doesn't start, chances are the problem stems from having a dirty furnace. Having dirt on your blower motor or flamer sensor could render your furnace unable to perform. When the blower motor is too dirty, it won't pass enough cool air to the heat exchanger, leading to equipment failure.
If you suspect delayed ignition, start with some basic troubleshooting. Check the pilot light and the gas supply. Ensure the pilot light is clean and the flame is blue in color. Also, verify that the gas valve is open and the gas pressure is adequate.
#1: Dirty Air Filters Block Proper Airflow
The truth is a dirty air filter is one of the top reasons furnaces don't work their best to warm-up a home quickly. The furnace will have a hard time circulating the warm air if the dirt and debris in the filter are essentially blocking it.
Checking your thermostat is the best place to start. Make sure it's set to “heat” and that you've set the temperature higher than the current room temperature. If that doesn't resolve the problem, try switching your fan to “on” to force the furnace to start working.
Most likely, your furnace is making a clicking noise and not providing heat because your furnace's spark igniter is trying to ignite your pilot light or burners but is failing to do so. In other words, there's an ignition system malfunction that needs to be fixed. Otherwise, your furnace won't start.
The Short Answer Is: Warning signs of a bad furnace ignitor include the furnace not starting or heating, a noticeable clicking sound without ignition, or frequent short cycling where the furnace turns on and off rapidly. Additionally, if the ignitor appears cracked or discolored, it may need replacement.
When a furnace takes longer than usual time to kick on like that, whether it's the first time you've turned it on in the fall or the end of winter, what's happening is that the furnace is trying to ignite, failing, and then trying again. I've heard of some older furnaces taking as long as an hour to finally heat up.
There are several reasons why your furnace may not turn on. The most common include a broken thermostat, gas line issues, clogged air filters, blocked ductwork, a tripped circuit breaker, and issues with the furnace itself.
The purpose of the reset button on a furnace is to shut it down before it can trip your circuit breaker. The need for this may arise if the furnace becomes too hot, or if there is some sort of electrical system interruption.
Once the indoor temperature drops below the thermostat's set temperature, the thermostat signals the control board inside the furnace to begin the heating process. The combustion process starts as the gas valve opens and the ignition turns on.
While all furnaces generate some ambient noise, they run quiet enough not to be disruptive most of the time. However, loud buzzing or humming can indicate various mechanical or electrical problems, either when the furnace starts up or throughout its operation.