How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Rick Your Own Question
Rick, HVAC Supervisor
Category: HVAC
Satisfied Customers: 22031
Experience:  40+ yrs. experience as a licensed oil & gas technician.
Type Your HVAC Question Here...
Rick is online now
A new question is answered every 9 seconds

Having issues with a carrier 58pha 090-16 thermostat and a

Customer Question

having issues with a carrier 58pha 090-16 thermostat and a code 33.
Months ago I removed the edge thermostat for a zwave thermostat so i can connect to my home automation system. Occasionally, the thermostat would call for heat or air conditioning but the unit would not always kick on. Typically, the batteries on the thermostat would need replacing, and then the unit would start up.
recently, i chnaged the wir filters to a higher merv filter....a few weeks later the unit wont turn on and throws a code 33. i assumed the filters are too restrictive and caused the lockout to take place. i reset the unit and removed one of the filters to see if the unit would start up. it would not....the burner would kick on but the fan would not turn on.
thinking it was the thermostat (as it was never "right"), i tried to hook up the original carrier edge the unit wont even turn on. no codes present.
i think the 58pha090 is a single stage the wiring for the t stat should be "fairly simple" i dont think i screwed this up.
i jumped the r and w on the board to see if the blower would fire up. it did.
is there anything special about the thermostat wiring for the edge that i missed? i have the RC and RH jumped. no dehumidification.
any help is appreciated.
Submitted: 1 year ago.
Category: HVAC
Expert:  Rick replied 1 year ago.

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation.

A 33 code is a limit circuit error. The blower running is normal for this error. You could try resetting the rollout switch(es) (see attached pic for typical). They are located just outside the burner chamber. Turn the power off to the unit then try pushing the small button between the 2 leads. If it clicks you have reset it and the burner will fire up with any luck when you turn the power back on. If t doesn't click it wasn't tripped. If that doesn't work then you could have a faulty limit switch or a bad connection along the limit circuit.

Customer: replied 1 year ago.
Rollout switches were not activated. Tried it again, furnace kicked on, relay for fan engaged on board (hear the click) but the fan never went on. Unit shut down and gives the 33 code.I then jumped the red and white again and left it the balance of t stat lines hooked up. The fan kicked on, code reset, and the furnace kicked on and ran normally.I reconnected the red and white again and tried to fire it up. Furnace light up but fan did not turn on....heat limit switch kicked on again.Please see the attached photo of the edge module between t stay and furnace. Not sure...but maybe the edge t stat is bad??
Expert:  Rick replied 1 year ago.

The 33 code has nothing to do with the thermostat but the wiring in you pic is pretty scary. Looks like you have bare stranded wire all over the place. As far as the 33 code goes the same potential culprits that I listed initially still apply. Also if the unit has enough time to cool down assuming the limit is actually working ok then you could have a clogged AC coil that's restricting the flow and causing the unit to over heat.

Customer: replied 1 year ago.
However...even with the unit completely reset....meaning no codes / led is constantly on...and I try to turn on the unit from the t stat, the furnace will ignite but the fan will not turn on. I can hear the relay on the board click for the fan, but the fan does not turn on.Likewise, if the unit is completely reset (no codes) the fan will not turn on at the thermostat.
Expert:  Rick replied 1 year ago.

If the blower won't run then you could have a bad start capacitor or a bad blower motor. If the blower doesn't run then you will get a 33 code

Customer: replied 1 year ago.
If I jump the r and w the blower turns on. If the capacitor was bad, the blower would not turn on.Am I incorrect?I looked for a capacitor, I do not see one on this unit. The wires run direct from the board to the motor.
Expert:  Rick replied 1 year ago.

Jumping R & G turns the blower on not R & W

Expert:  Rick replied 1 year ago.

We need to make a distinction between the draft fan (on the exhaust) and the blower (moves air through the ducts. You seem to be using the terms interchangeably. If you jump R & W at the board the draft fan should start. If the fan doesn't start when you turn up the thermostat then you could have a bad stat or maybe a break in the wiring between the stat and the furnace

Customer: replied 1 year ago.
I have been speaking the about the blower...sorry to confuse.Jumping g and r give me a click on the panel with nothing coming on.Jumping r and w turns on the exhaust draft fan and cycles the furnace.Sounds like I got s bad control board
Expert:  Rick replied 1 year ago.

If the furnace runs properly with R & W jumped then there's nothing wrong with the furnace.

Customer: replied 1 year ago.
when i say r and w "cycled the furnace" it turned on the exhaust draft fan and fired up the burner...but the blower did not turn on.
Expert:  Rick replied 1 year ago.

Ok so you need to determine if you have power to the blower once the burner fires up. If you do then, like I said before, you either have a bad capacitor or a bad motor. If you don't have power to the blower then the board is suspect