[Mogwai]

I tried posting 4 hours ago but nothing has showed so sorry if this gets duped(I'm new to forums) I have the same rollout overload sensor but mine is located above a heat shield. I did not notice a heat shield in between the rollout overload sensor and Darques burners. Could this be the reason for the trip after 20 seconds of flames? I would love to remove my heatshield and be your guinea pig but I'm not sure if its safe, and I already have a hard enough problem starting my furnace as is. I am a step up from a retard when it comes to furnaces.

[hvac1000]

The heat shield is there for a reason. Do not remove.

[Mogwai]

The heat shield is there for a reason. Do not remove.

HVAC1000 You misunderstood, I am not Darque. Just someone who also has close to the same problem as Darque. I looked at Darques pictures on Page 3. I did not notice a heat shield present in Darques supplied photos. Shouldn't there be one? Restudy Darques photos on page 3. Darques overload sensor seems to be awfully close to burners.

[hvac1000]

((HVAC1000 You misunderstood, I am not Darque. Just someone who also has close to the same problem as Darque))

Here is the problem. You should have started a new post for you only. Then you could reference his post. What happened is that the water gets muddy when over one person is posting or adding questions to the other post that is not his. Can you understand that.

Now with that being said many times a manufacturer will make running changes to the same model furnace. They will say this picture or part is good for furnace serial numbers up to 12349. Then another drawing will show a different added piece or a deleted piece and then it will say this drawing is good for units from 12350 to 32112. Same furnace different serial number. Now can you understand that?

NEVER remove any part or replace any part that is not supposed to be there.
Manufactures spend millions of dollars engineering a piece of equipment. It is UL or CSA approved the way it is shipped from the factory. What you start to remove or add things to the furnace you do two things.
First you remove the UL or CSA listing because it has been modified and you might not get paid if the equipment causes a fire. Insurance specialists look for items removed and replaced with non compliant items. Then they car refuse to pay for the damage caused to the building.
Second you could jeprodise your and your familys safety.

How do I know all this junk? Over many years as owner of a large company the State Fire Marshall would request that I visit buildings with him to give him my 2 cents worth as to the probable cause of the fire. When on those jobs I met many insurance investigators that told me exactly what they look for so there company could skate on paying some or all of the claim.

[T-Top]

One more thing that would make it look like a bad flame sensor is a small restriction in the vent pipe it would open the pressure switch once the hot gas built up in the vent. That control board should have a light that comes on to let you know it is sensing the flame. I think it may be yellow or green. It should say flame sensor above or bellow it.

[Mogwai]

Sorry Hvac, this is my first forum. Didn't mean to come off the wrong way, just wanted to say that my furnace has a heat shield and my sensor looks just like Darque's, thought I could be of some assistance by sparking a different idea. Thought maybe by someone working on it maybe the shield didn't get replaced at some point in time.

Again I apologize for piggybacking.

[hvac1000]

No problem and yes the heat shield could have been removed but I have no way to find out for sure.

[darque]

Fyi to all, had to end up replacing board & adding sensor kit. This has no sensor and rheem wouldn't tell me if the his was also a sensor, thanks for info to those who tried to help

[hvac1000]

Something in the furnace is causing a short cycle time. Could be the high limit or dirty air filter or dirty A/C coil inside the furnace plenum not allowing enough air to pass causing the high limit to trigger..