no heat coming out of vents in house

No Heat Coming Out of Vents in House-Help!

If you have no heat coming from the vents in your house,

There are 4 things that you can look for that are super easy and will save you a lot of money.

  1. Check the Filters
  2. Check the Thermostat Battery 
  3. Make sure the Igniter is firing
  4. Clean the Sensor

This article will layout a few tips on what to look for and how to easily get the heat back on.


Recently as me and my wife are going to bed on a Saturday night we begin to notice that our bedroom is getting cold.

Upon inspection, it became pretty clear that the whole house was getting cold including our two daughters’ bedrooms.

Our house is heated by a Rheem Criterion furnace that sits in the Attic.
Not the most convenient thing to get to late on a Saturday night so we decided to just bundle up and go to sleep.

And also since it was Saturday night and the next day would be Sunday morning, calling a HVAC service guy over to take a look at it was going to have to wait till Monday anyway.

We woke up to a house that was about 50°. Not the worst, but definitely chilly.

My wife lit the fireplace and everybody kind of migrated to the living room. So it’s not like we didn’t have any heat.

Having an HVAC technician come to your house is going to be potentially expensive regardless, so I knew I was going to take a look at it myself before doing so.

We’ve had a few instances in the past where we had to call out a heating and air service, so we knew a little bit of what to look for before we called up somebody.

Let’s just say that some of the problems that can occur with your heating can be so easily rectified that calling someone in to fix them can lead to embarrassment.

So these are the 4 things that I know to look for based on experience. There are probably way more things that can be the problem at any time, but these are the things that have helped me out more than a few times.

4 Things to Look for When You Have No Heat

That leads to the first thing to look for when you’re not experiencing heat coming from your vents.

1.  Check your filters.

 If they are too dirty, your system will not be able to get any air flow and it will eventually block the heat from coming out of your vents.

Paying a HVAC technician to come out and inspect your furnace, only to emerge with a dirty filter is an embarrassment and a cost that is easily avoided.

Ask me how I know….

Replacing the filters is too easy and could easily be your problem.

2. Thermostat Batteries.

 Make sure the batteries in the thermostat have not died. This is another super easy diagnosis that can be easily checked and rectified. And a huge embarrassment and cost to have someone come in and “fix”.

These days you can purchase thermostats that will send you alerts when your battery is dwindling down.

But I will venture to say that most of us don’t have that feature so it’s important to check your thermostat from time to time for a” change batteries soon” message on the actual display face.

If your heat is out and you go to check your thermostat to see what the temperature is but the display is blank, your battery is probably dead. Thus no way to control the amount of heat.

Simply, change the battery.

3. Igniter not working

 Now we’re getting a little further down the rabbit hole on possible things that could be keeping your furnace from heating your house.

This will require you to take the face off of your furnace and most of the time this is where most people will stop and just call a service man. And I don’t blame you.

But if it’s Sunday and you’re like me and don’t like to pay a bunch of money only to find out it was something super simple that I could have fixed myself,

Then let’s venture on.

Important , Be sure that you turn off the electricity to your furnace via the breaker box. The breaker box is a easy suggestion but you may find that there is a on and off switch that controls your HVAC close by ( because if you’re installing a HVAC in the attic, you sure don’t want to have to be running up and down to use the breaker box to turn it on and off). At the very least there’s probably an outlet that it’s plugged into that’s easily accessible.

Here’s what you’re going to want to watch for.

1.  Does the igniter get hot and light the furnace?

If you have an older furnace that has a pilot light, then you can tell very easily whether or not the pilot fire light has blown out.

If it has, set the dial to pilot, relight and hold the button down for about 10 seconds. The pilot light should stay lit and then you turn the dial on and you’re set.

But… And this is where most modern homes will fall,
If you have a newer furnace then you have an igniter called a “hot surface igniter” that heats up and eventually fires up the gas.

Here’s the important part:  If the igniter doesn’t get red or gets red and fizzles out real fast, then the problem with your heat is that your igniter is not functioning.

Igniters generally run under 30 bucks and come off with a screwdriver or a quarter inch socket pretty simply.

If you have a igniter that has stopped functioning, then replacing it is a simple process that will save you a bunch of money versus calling out a HVAC tech.

But they are a “part” that you can’t generally just go down to the hardware store and purchase. So if it’s a Sunday, prepare to wait it out another day till Monday to buy one.

Again, ask me how I know…

4. Sensor

 If your igniter works fine, then the next easiest thing to look for is the sensor.

Btw Congratulations if you’ve gotten to this point, because most people we’ll have bitten the bullet and called out a serviceman by now.

But this is another thing that is easy to fix and usually will not cost you a dime to do so.

But if you call out a HVAC technician, he will probably charge you over $100 for this.

The sensor on your furnace is usually located on the opposite end of your igniter. It is a small probe looking piece that is inserted into your furnace to tell the furnace went to come on and go off.

The problem is that these things get covered in Ash and soot from the flames.

And even though the part itself is very inexpensive, most of the time you can easily remove the soot from the sensor with a piece of sandpaper.

Look…Here is an easy diagnosis to determine whether or not your sensor is dirty
and needs attention is to turn your furnace on and watch as it fires up.

If the igniter comes on like normal and fires the gas up like normal BUT the furnace quickly fires down again.

Then you have a dirty sensor.

You may have to do a little Googling to find it on your specific furnace, but generally it will be held in with a couple of small quarter inch bolt screws at the other end of the burners from your igniter.

You simply pull it out and sand it clean. Reinstall it and turn the furnace back on.

I learned this trick by watching a HVAC guy that I called out to get the heating going in my house. He came in, looked at the heater for about 2 minutes, pulled a tiny piece of sandpaper out of his pocket, did some mysterious thing with the sandpaper, then wrote me an invoice for $120.

I knew right then, I was getting financially had over a tiny bit of knowledge that I did not have. And with the internet available 24/7, it was inexcusable for me not to have it.

Cleaning your sensor yourself is super easy and will save you that money!

No Heat Coming Out of Vents in HouseConclusion

That’s as far as the rabbit hole goes for me, but I’ve been able to diagnose and fix the problem based on these 4 easy solutions more than a few times.

Of course this is not an exhaustible list. Nor is it always going to be one of these solutions. For instance, if a new battery does not fix your thermostat, then it may be time for a new one or something else. Not everything is cut and dry.

But these tips have helped me and I’m glad to share them.

BTW, It was the igniter in the specific instance that I was sharing at the top of the article. Saturday night is a very inconvenient time for HVAC issues. To say the least!

Thanks for taking the time to read

Published by

Dennis Reed

Dennis Reed Owner and Author @ BreatheBetterAir.org