The return should suck more

Skill level skill2

We had turned off the heat in the house while we were gone for a few days (which saves a lot of electricity, by the way) and turned it back on using a web app about three hours before we returned. That remote control of the temperature is a very handy feature.

Energy usage chart shows how setting back the thermostat can save big time
Energy usage chart shows how setting back the thermostat can save big time. The wavy brown line is the outdoor temperature and the red area is when the heat is on while we are there over a winter weekend.

Normally it takes 2 – 3 hours to get the house back up to a comfortable room temperature if we let it get down into the 50s. It was pretty chilly outside when we arrived and my ever-loving wife, “Gladys” (not her real name), said it felt good to be inside. The indoor temperature, however, was still in the lower 60s downstairs. Upstairs was fine, which is understandable since heat rises.

Suffering by degrees

After an hour the downstairs had only gone up about one degree. That just ain’t right.

The downstairs hallway was really cold. The floor was 50 and the ceiling topped out at about 62. The ceiling should be in the 70s at least because heat rises and the heating vents are in the ceiling on this house. Why was it so cold?

Thermal leak detector
(Click to see on

I have this nifty infrared thermometer thingy that you can point anywhere you want and see the temperature at that spot.

You can point it at a “reference” spot and make that the “normal” temperature. Then when you point it somewhere else it will shine a green light on that spot if it is roughly the same temperature as the reference temperature, It will shine a red spot if it is a few degrees warmer and a blue spot if it is, wait for it, a few degrees colder!

So I pointed it everywhere I could think of. The floor was colder but I couldn’t find any big air leaks of cold air. I checked the adjacent bathroom and bedrooms. Nada. There is a big air return vent in the ceiling of that hallway and I pointed at it.

Air return in the ceiling of the hallway
Air return in the ceiling of the hallway

The spot of light was still green, in other words, not much different from the rest of hallway. It really should have been cooler than the surrounding ceiling because it would be drawing some of the cooler air from below.

The air return vent also didn’t seem like it was drawing much air. Usually you can hear air as it moves through vents but this one was pretty quiet. It just didn’t suck enough. Air, that is.

Air handler can’t handle it

Air handler in the attic
Air handler in the attic that blows air downstairs

Our house is actually heated or cooled by the heat pump or air conditioner, which is outside. The air handler is inside the house and blows that conditioned air through the ducts and into the rooms of the house. We had had trouble with the downstairs air handler before because it didn’t seem to want to turn on the fan that blows the air into the room. It took several visits by the guys from the company who installed it to eventually figure out it needed to be on a setting for a different size heat pump. Now it seemed like it was back to its old tricks.

It was late so I gave up for the day and went to bed.

The next day I decided to take some insulation up into the attic to stuff into some gaps between the second floor joists. Out of the corner of my eye I noticed something that wasn’t right.

Removable panel for changing the filter
Removable panel for changing the filter

On the air handler there is a removable panel for changing the air filter. You take off the panel, slide out the old filter, slide in the new one, and snap the panel back on.

Except this time someone (who shall remain nameless, but is the “pro” from that same company who did the last maintenance) had not snapped the panel back on correctly. It was hanging down and about to fall off.

Filter panel falling off
Filter panel falling off

Needless to say, I had found the reason why the downstairs was taking so long to heat up and why the return vent wasn’t sucking very much air. The air handler had been drawing air from the attic right through that access panel. We were heating the air from the great outdoors.

Here is a close-up of the little hook that is supposed to catch in the slot in the corner.

Close-up of hook and slot for filter door
Close-up of hook and slot for filter door. (Click to zoom.)

It is easy to see how someone could miss that little detail when putting the door back on. There is duct tape residue on the side of the panel where a befuddled tech tried to keep the panel in place.

With the filter panel properly seated in the air handler, my ever-loving wife, Gladys, is toasty warm downstairs.

Now that air return really sucks.


2 thoughts on “The return should suck more”

    1. The energy usage chart is one of the benefits of installing a web-based “smart” thermostat. You buy a little control unit that sits between the thermostat on the wall and the air handler or furnace. You plug an ethernet cable into it or use a wireless connection so that it can talk to the internet. Then you use a web browser to set the temperatures for various times of the day and other options. The company that supplies the control unit collects information from it every few seconds and you can view various reports based on that information by again using a web browser.

      I got my unit from BAYweb.

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