Thanks to all – here is some info:
PVC is 4" diameter
The thermostat is EVOLUTION (not INFINITY) – I googled but didn’t find much I can use. Will try some more later.
Filters (electronic) are clean (and were cleaned 1 month before this “hurricane” of alarms started).
The units were registered on time and I have written confirmation from Bryant about the 10 year warranty.
Evolution & Infinity is exactly the same thing. Evolution is Bryant & Infinity is Carrier. Exactly the same thing.
Can someone please explain to me -
Why is there never enough time to do it right the first time, but plenty of time to do it twice?
1st floor is about 2800 sq ft; 2nd floor about 1800 sq ft.
Changing the pipe looks to me like a "big project" and, in addition, if the pipe size is the culprit, I wonder why these problems didn't happen in the first year.
There is something interesting that I would like to point out – maybe it is relevant:
The technician replaced the inducer motor and cleared the alarms on 1/28/2011.
During the following 4 days there were
CODE 42 INDUCER FAULT – 30 alarms
CODE 33 LIMIT FAULT – 2 alarms
On 2/1/2011 “SYSTEM MALFUNCTION” message was displayed and CODE 33 LIMIT FAULT was displayed as ACTIVE.
I then turned system off (thermostat), then turned furnace off and (after 2-3 minutes) back on, then turned the system back on (thermostat). As a computer engineer I thought that it might be important that the system is off when I turn the furnace off and back on.
Since 2/2/2011 until 2/5/2011 (3 days) the system has been much more “quiet” even though the weather is cold in Chicago:
CODE 42 INDUCER FAULT – 1 alarm
CODE 33 LIMIT FAULT – NO alarms
CODE 31 MEDIUM PRESSURE SWITCH OPEN – 2 alarms (never seen before!)
“SYSTEM MALFUNCTION” message - NONE
Obviously, 3 days is a very short observation period but the difference is striking.
Sounds as if you have several problems. Have your technician remove air filter, check to see if unit is overfired, check heat rise.This is all relevant to code 33, check wiring harness from inducer fan to variable speed furnace control, check condensate piping , check for obstructions in vent pipes(code 42) Variable furnace control may be defective. There are numerous things to check and without being there it is impossible to troubleshoot. A qualified technician is needed.