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Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 5648
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I am having problems with furnace. I'm getting fault 33 high

Customer Question

I am having problems with furnace. I'm getting fault 33 high limit fault. What does this mean
JA: Did you check the furnace's filters?
Customer: No I will do that now
JA: Do you plan on doing the work yourself?
Customer: Yes
JA: Anything else we should know to help you best?
Customer: Not yet Thank you very much
Submitted: 3 months ago.
Category: HVAC
Expert:  BillyHvac replied 3 months ago.

Hello,

My name is ***** ***** I will do my best to assist you. I am looking over your question now and will respond shortly.

Expert:  BillyHvac replied 3 months ago.

Is this a Carrier, Bryant or Payne unit?

Customer: replied 3 months ago.
Carrier
Expert:  BillyHvac replied 3 months ago.

thank you.

Is it still locked on 33 code?

Customer: replied 3 months ago.
Customer: replied 3 months ago.
It works in the emergency mode
Expert:  BillyHvac replied 3 months ago.

in the upper section is a flat plate the size of a credit card..it is mounted flat against the front wall.

It has 2 wires attached..

Locate that flat plate and tell me when you have found it.

AND is the blower running and filter clean?

Customer: replied 3 months ago.
Blower running and filter was just replaced today but it looked clean
Customer: replied 3 months ago.
I see plate
Expert:  BillyHvac replied 3 months ago.

turn power off to furnace...tap the plate as described 3-4 times. Med taps...like rapping on a door lightly.

Turn power back on and tell me code

Customer: replied 3 months ago.
Fault 34pilot proving fault
Expert:  BillyHvac replied 3 months ago.

thank you..so now the exhaust fan starts...

Do you see a glow or get 3 seconds of flame?

When did furnace last run?

Customer: replied 3 months ago.
but when I turn dip switch 4 on everything runs normally.
Expert:  BillyHvac replied 3 months ago.

What is model number of the unit?

Customer: replied 3 months ago.
Flames keep going out in normal operating mode. On diagram there are several model #s 320A,321A,398B,58sxb,58vca,58vua This is a Carrier WeatherMaker high efficiency. Infinity furnace
Expert:  BillyHvac replied 3 months ago.

so we went from a code 33 and no ignition...

Tapped on plate...

Now we light but flame goes out in 3 seconds with a 34 code?

Customer: replied 3 months ago.
Now it's back to 33 code
Expert:  BillyHvac replied 3 months ago.

ok,

how long is the furnace running with flame before it stops and reverts to 33?

Customer: replied 3 months ago.
About 10 seconds but retrying to start flame several times then shuts down for a while then repeats
Expert:  BillyHvac replied 3 months ago.

thank you.

at one end of the burner is the glow ignitor.

At the other end is a flame sense rod. It is a metal rod with a white ceramic base and one wire.

Locate this rod and clean it with steel wool.

Tell me if flame stays on

Customer: replied 3 months ago.
If it runs in emergency mode wouldn't this be ok? Iam trying to get apart. There are 3 wires going to bottom and 1 to the top of same block the top one goes to spark ignitor black box
Customer: replied 3 months ago.
Do I have to take off gas line to get out
Customer: replied 3 months ago.
putting back together because I have to go to work. I put back to emergency mode till I get back tomorrow morning.now I'm getting a 31 fault- high pressure switch in normal. Back to emergency mode and runs good with out any faults
Customer: replied 3 months ago.
Thanks for your help so far
Customer: replied 3 months ago.
I got charged 23$ twice and 5$ twice I didn't approve of this only 5$ once will this be refunded?

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