You set your thermostat at 70, the furnace runs, but the house just won’t warm up.  What’s up with that?  A fix could be simple—change your furnace filter.

When a dirty filter is the culprit, air does not flow through smoothly.  That can overheat the furnace and cause it to short cycle.  As the furnace continually shuts down, not only does it fail to warm the house, but stresses the furnace and may cause damage.

Can’t you just dust the filter off, reinsert it, and be ok?  The filter captures all sorts of specks of who knows what. A simple dusting is no match for microscopic particles.  A new filter is a wholesome investment in your health, greater comfort, and the problem-free operation of your furnace.

What should you look for in a new filter?  The best match for your furnace.

Filters have Merv performance ratings. The higher the Merv number, the filter potentially captures more, and finer, dust.  But a word of caution.  A larger number is not always the best solution. Mechanical Extremes’ Harold Wilkes says “if the Merv rating is too high, it can suffocate the furnace.” That can lead to poor functioning and damage. The recommended Merv rating will depend on your furnace.  For a one-inch thick filter, a rating of 5 to 7 is about right. For 4-inch filters, 8 to 13 is appropriate. Best to check manufacturer specifications to find what’s right for your situation.

What’s the recommended timeline to replace?  Change one-inch filters every month and the four-inch every 6 months—more often if the home air is compromised with smoking, pet dander, or in a dusty area.   The thermostat on many of the Carrier furnaces that Mechanical Extremes installs will alert you when it’s time for action. Other units can be set to remind you on a time basis.

If you have questions, or would like to transfer this worry to a professional, Mechanical Extremes can help. (517) 812-2484.