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
.
Why does my heat take so long to turn on?
This could be a problem with the gas flow, a bad igniter, a misaligned igniter, a dirty or bad flame sensor, etc. The best way to start diagnosing the problem, is to observe the ignition sequence.
Set the thermostat to heat
, and turn the set point down so the thermostat calls for heat.
What causes furnace delayed ignition?
Dust and lint. 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.
Why is my furnace short cycling?
The most likely cause of short cycling is
the fan limiter
, which prevents fires and furnace damage by shutting the system down if the heat exchanger becomes too hot. … A dirty flame sensor or damaged thermocouple will shut off the gas valve and the furnace. This prevents natural gas accumulations that could cause a fire.
What to check if heat is not working?
Check your power source—a tripped circuit breaker or blown fuse could be the reason for your furnace failure. Reset your breaker or replace the fuse to see if that restores heat.
Check your filter
—if it's so dirty that your system is struggling to move air through it, your furnace could overheat and shut down.
Why isnt my heat working in my house?
If your furnace does not heat at all.
Thermostat malfunctions cause most heating system failures
. Other causes include a tripped circuit breaker or blown fuse, or—in the case of combustion furnaces—a pilot light that has gone out.
How do you fix delayed ignition on a furnace?
Delayed furnace ignition is an easy problem to avoid. All you need to do is have your
furnace cleaned properly before turning it on
each fall. A New Britain heating technician will clean the burners and ports and remove any dust, lint, rust or sulfur buildup that might block ignition and cause a delay.
What are some possible causes of delayed ignition?
Delayed ignition is usually caused by
dirt or a minor fault
. In most cases, a technician can solve the problem by performing some basic furnace maintenance or replacing a part. Others causes call for more extensive repair work. In a gas furnace, the air-to-fuel ratio may be off, making the gas hard to ignite.
Can hear your furnace click on but it does not fire up?
The Pilot Light (Faulty Ignition Sensor)
The pilot light or ignition sensor is usually the most common issue when your furnace will not ignite. This is typically the problem if you can hear your furnace click on but it does not fire up. … If the sensor or ignitor is dirty, it will need to be cleaned.
What do I do if my furnace is short cycling?
If you suspect this is the reason your furnace is short cycling, it is imperative that you
contact an HVAV professional to repair the unit
. Restricted airflow is typically the cause of overheating which may be due to a dirty air filter or interior vents, or because roof exhaust vent is blocked.
Can a bad thermostat cause your furnace to short cycle?
Your thermostat could also cause the HVAC
system to cycle on and off rapidly
, a process known as short cycling. Your furnace or central air conditioner spends a good amount of energy simply turning on and off, which is why you want yours to run for at least 15 minutes at a time before shutting off.
Can a dirty filter cause a furnace to short cycle?
A
dirty air filter
is the most common cause of short-cycling. If your air filter is clogged with dirt, it won't allow proper air flow to the heat exchanger. That can cause the furnace to overheat and forces the high limit switch to ride to the rescue by shutting the furnace off.
How do you know if your heat is on?
Once you feel hot air coming through your vents,
walk outside and see if the outdoor unit is running
. You see, a heat pump is an air conditioner that can also provide heat during the winter. So if the outside unit is running and producing heat, then you have a heat pump.
Why is my furnace blowing cold air when the heat is on?
Your furnace may be blowing cold air
because the filter is too dirty
. A dirty air filter blocks airflow over the furnace's heat exchanger, causing it to overheat. When overheating, your furnace can trip a high limit switch, causing the furnace burners to shut off so that the heat exchanger does not crack.
Why is my electric furnace not blowing hot?
Thermostat Issues
If your electric furnace is not blowing hot air, there might be some issues with the thermostat. … If your thermostat runs on a battery unit, you need to check regularly if the battery is dead. Such batteries tend to send faulty temperature reading. This problem is especially common in older units.
