The equipment is doing just as it should. Your contractor needs to address the undersized duct in your home. Did they make any changes to the overall size of the duct?
I'm a consumer who just had installed a new Carrier Infinity 96 along with that make's top diagnostic thermostat installed in a 20 year old suburban home in the snowbelt.
I had installed the standard Carrier media filter that came with that unit as well.
It seemed like a really professional installation from one of the city's most reputable dealers, and it's great to listen to how the furnace gradually and almost silently ramps up as required (especially as compared to the noisy 50 - 60 % efficiency belt-driven single-speed furnace I had before).
However, there has been a persistent problem: every two or three minutes (after re-set each time) the thermostat displays the message "clean or replace the air filter". I've removed, inspected and replaced the filter, which appears to be fine. I called the installation contractor and he said to ensure that all air duct inlets and outlets are open and unobstructed, and I've done so, and they are.
He said the "replace" message is triggered by the DC blower motor having to draw more power than it should, due to an obstruction in the overall breathing in and out of the system. Which, of course, would mean that the motor is working harder, and costing more to operate, than it should.
Does anyone have any ideas as to what is going on here? It's a bit like buying a new car and having the check engine light turn on every few minutes - disappointing at best!
You guys are the experts - without knowing anything about that thing in the basement, I studied your forum here in detail for a couple of weeks before settling on the Carrier 96 - & I hope you can help.
Thanks in advance
The equipment is doing just as it should. Your contractor needs to address the undersized duct in your home. Did they make any changes to the overall size of the duct?
Perhaps you should have read the instructions before calling.
See what it says yout esp is.
If you take the filter out and run it do you get the same message ?
Take the filter out and leave the filter door open, increasing the size of your return temporarily, then call the contractor and have them add some return duct to the system, if you want, go to advanced settings and check the static on high cool or high heat.
it sounds like you might have a duct problem wereby it is too small to handle the air at it proper volume.
Or, it might be sized so tight that the added static presure of the filter is enough to set it off.
I might even shut off the service switch and reach up into the blower wheel and just make sure there isn't anything stuck up in there
You need to find the total external static pressure on the system. Should be .50" in w.c. Start with the return side since your getting that message. Check it after the filter and before the blower should be about .20" to .30" w.c. Im surprised your not getting blower out of calibration fault code.
Infinity can handle up o around .7 ,and everything will work just fine.
Either your original ducts are undersized,very common,or the addition of the filter push the total static or the "limit",very common also.
They should test return and supply static separately,to see where the problem is the worst,and where the best opportunity to correct it is.Often the return side is the best opportunity to reduce the static,adding a return duct and grille may solve it.
We ask that our guys and gals check the ESP before any sale,so we can include duct modifications i our estimate and do them at the same time.