Filter Troubles

Just a friendly reminder out there to all my friends to go to the store and grab a furnace filter.  Grab 3 or 4.  Because you need it. 

Set a reminder on your calendar, phone, and smart thermostat to change your filter every 3 months (at the very most) - or more often if you are undergoing construction.

We had not replaced our filter in 6 months.  Yes, I know.  That's really, really bad.

Why didn't we replace our filter? We are in the market for a new furnace.  And we might as well save ourselves the $10.  Wrong. wrong. wrong.  So. Wrong. The furnace is antiquated and struggling.  It has quit on us for numerous reasons over the past 12 months (igniter switch, loose wire, and a loud blower motor).  And once we added 400+ square feet to our house, our finicky furnace was being pushed above it's limits.  We knew this.  

Why didn't we replace it once we finished the add-on 3 months ago? Because we like living on the edge.  That's why.  And, frankly, because we forgot. And we couldn't be bothered to remember our filter size. Do you know how cold Michigan is? Well, we do, and we really like waking up to a house heated to 68.  But it seemed silly to replace a furnace that was still working, so we thought that we could just cross our fingers and push it to the limit.

When our furnace started slowing down the other week, we immediately jumped to the conclusion that it needed to be serviced yet again and we were ready to replace it.  I had the cash in my hand and my HVAC professional on speed dial. 

Our furnace was short cycling.  The thermostat and the furnace were turning on and off every 60 seconds.  This didn't allow our house to heat up properly, so the thermostat was quickly dropping... 67. 66. 63... Okay, furnace, you have my attention.

Before calling in the pros we tried self-diagnosing the short cycling furnace. We replaced the thermostat and checked the wiring for any loose connections.

Our house was still cold.

I dialed up our HVAC contact and told him we were ready for a new one.  Our guy stopped by to write up a quote...and then (out of curiosity) removed the filter.

Our problem wasn't a bad ignitor, an overrun blower, or corroded flame sensor, and it wasn't the power supply (or the thermostat).  It was a clogged filter.  Let me repeat that.  A CLOGGED DISPOSABLE FILTER. 

Just look at that!

Guys. I was mortifying-ly embarrassed.  Because it took a service call from a professional to tell me this.  See, I knew we had surpassed our 3 month swap out period, and I had very good intentions to replace the filter. I knew we needed a new filter, I just forgot. Never once did the filter relate to the short-cycling furnace - not in my mind anyway. 

I now have the size recorded in my phone. And on my blog.

A clogged filter can cause inefficiency and short cycling.  In our case, it probably reduced the life of our furnace even more.  Have you ever had bronchitis? The tubes in the lungs swell causing breathlessness and coughing.  In this case, the dirty filter is that swollen mucus membrane and the blower motor is the lung of the house.  Of course this furnace couldn't breathe!

Moral of the story? Replace your filter, folks. And install it correctly. Otherwise you could potentially cause more damage.  See photo above for correct installation. 

I installed a 'test' filter incorrectly for 5 days (inserted the wrong way).  I left the filter in place for only 5 days, and you can see that the filter is misshapen.  I checked on it daily to make sure it was still a-okay. Had I left the filter incorrectly installed it may have disconnected from the cardboard and gotten caught up in the blower motor.  Which would cause a whole new set of issues.



Take this as a lesson learned from us.  Do yourself a favor and replace that filter.