Super Hot Upstairs

jstewar9

Hello - I live in a two-story house with two-zone (downstairs and upstairs) heating and A/C. Each zone is controlled by a separate ecobee thermostat. Our furnace is in the attic. This morning there was a 15 degree difference between our downstairs and upstairs thermostats. The second story is usually hotter, but this is larger than normal. The downstairs thermomstat kicked in before we woke up, but it seemed like our upstairs was getting more heat.

After testing, I’ve found that:
+ when our downstairs thermostat triggers heat: 1) only 2 of 4 reachable vents have hot air and high flow. The vents in my living room and master bedroom are barely warm and not moving much air. 2) all upstairs vents are pushing hot air with high flow.
+ when our upstairs thermostat triggers heat: 1) none of the downstairs vents are pushing hot air 2) all upstairs vents are pushing hot at high flow.

It seems like this is not how should it be working, right? Ideally, the downstairs thermostat would only push hot air through downstairs vents and same for upstairs, right? For now, I’ve closed our upstairs vents, but wondering if I need a different solution.

neilc

so is this a zoning system? with one furnace?
or,
I'm guessing a unit upstairs, and a unit downstairs , ,
which?

HVACNUT

Of one furnace and two zones, it seems to be zoned with dampers in the ductwork. 
Upstairs seems to be stuck open, which if 2 wire (power closed, spring open) there's probably no 24 volts to the damper motor.
If 3 wire (power open, power close) could be no 24 volts or stuck.

EBEBRATT-Ed

probably stuck or damaged dampers.

jstewar9

Yes, one furnace with a zone upstairs and downstairs. Seems like the dampers may be the culprit. I can look into that. Is that something I can test, or should I call a pro?

Jamie Hall

You can do some testing yourself -- find the dampers and see what they are set at and see if they can be adjusted. If you can't find them -- or if they simply aren't there at all (not all forced air systems are constructed with the care they should be) -- it may be time to call a pro.