Wednesday, March 12, 2014

Rheem Criterion Iiheat Cycle Works Then Shuts Down

I'm having a problem with my gas furnace and don't know where to start to find out what it might be. When the thermostat calls for heat, the draft inducer kicks on, the ignitor glows, the gas starts and burns for a short time and then shuts off. It tries this whole cycle again, with the same results. Sometimes the blower runs by itself with no heat.
Can anyone make suggestions as to what this problem might be? I'm hoping it's a part replacement and not a big deal...
Thanks in advance for your help!

When you say a short time, do you mean a few seconds?
If so, the flame sensor is the number one suspect. Check connections and wires to the sensor. If that looks OK, then remove and clean the metal rod with pure steel wool (not Brillo or any type with soap). Also clean the metal base where the screw is. This is your ground, and is just as important.
Does the circuit board have an LED? Is it flashing a code?

For anyone encountering a similar problem, this is what I did to fix it:
--Locate the flame sensor rod (it should be a piece of metal that is in front of one of the burners--usually one far from the ignitor).
--This is usually held in place with a single screw. Take it out and clean it with steel wool or fine sand paper.
--Replace sensor rod and put everything back together in reverse.

Thanks, Jim! Actually saw your post after I cleaned the sensor rod. It definitely worked and saved me the trouble (and cost) of having a technician come out to the house. Many thanks for your fast reply!!

Good work. It looks like you have potential in the HVAC field.
Glad it worked out.

Hey, just wanted to say thanks! I had this same problem with the same furnace and did what you said and it Worked!

Same issue, same furnace. It's blocked by a panel and the panel is preventing me from unscrewing it. The panel appears to be over the ignitor. I am afraid if I get it unscrewed that I won't be able to get it back on. Any other ideas? It doesn't help that it's zero here today. I am so glad I found this forum!

Nevermind! I just wasn't sanding the sensor with enough gusto. It was not easily detachable and blocked, but I got it done. Been running now for over an hour. Thanks for having this one out there!!

Please don't revive old threads. It rapidly becomes confusing.
Start a new thread and report the make and model of your furnace and the sequence of events that occurs when you turn up the thermostat.
The more detailed and accurate your report, the better the quality of the help we can provide.

You made me look like a hero to my now warm and toasty wife. I owe ya one.

I had a similar problem with my furnace, it would light for a few seconds and then quit. I turned out to be the furnace control bard on mine. It was working fine for a month after the repair and now as of yesterday my furnace wont light. The sparker(igniter) seem to work fine, the blower is working fine but there seems to be no gas getting to the furnace. Any idea what could cause this? Thanks!

Tags: cycle, then, shuts, problem with, clean metal, flame sensor, problem with furnace, same furnace, short time, similar problem, steel wool