Jump to content

Airco AH-90MD runs a lot


Recommended Posts

Hi, I have an Airco AH-90MD. It seems to cut in and out more often than it needs to. In the mornings, it might run for 5 mins, cut out for 3-4 mins and then run again.

House is bilevel around 1050 sq ft on the main floor. I'm wondering if it's undersized for the sq footage of the house or what else might be the problem?

Link to comment
Share on other sites

Time is all relative and no general rule of thumb should be used.

Have the unit serviced and determine if it is cycling on the thermostat or other safety switch.

For a properly functioning system, in general "on" time for any heat source is determined both by capacity of the furnace as well as the "load" of the house in which it is installed.

The "off" time is determined solely by the effective insulation of the structure in relation to the temperature difference between indoor and outdoor temperatures.

So run time is determined by the furnace and

off time is determined by the house.

A properly sized system will run almost continuously at design temperature, which is generally the historically coldest temperature for your location.

Link to comment
Share on other sites

Crank the thermostat up to 27 or 28.

If it continues to short cycle (run for 5 minutes, turn off for 3-4 minutes, and run for 5 minutes again), then it's probably shutting down in response to the high temperature limit switch. In that case, before doing anything else, try changing or cleaning your filter.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...