Roll Out Switch Diagnosis

On this Saturday call I respond to a no heat where I had to perform a roll out switch diagnosis. The roll out switch tripped and I had to figure out why.
In this video we discuss how to check evaporator superheat using testo smart probes in a walk-in cooler. Checking superheat at each evaporator on a multi evaporator system is important to system performance.
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[@hvacslayer2929]

Lol damn that unit with its own gazebo those stairs gnarly 🤘🏻

[@HVACKnowItAll]

Hell yah! Lol

[@actechformallyyomama746]

I think you got it right. Had the same problem with Carrier gas pack. Had 4” at the manifold. It doesn’t take much when it’s a small unit. Stay safe

[@diplenski]

i would have suggested checking the heat exchanger, also amp draw of inducer, and check exhaust for possible/partial blockage

[@HVACKnowItAll]

I did check the heat exchanger, you should watch the entire 😆😆. The unit has been running call back free.

[@diplenski]

@@HVACKnowItAll my bad i missed it first time, not trying bust balls. also good to check between cells closest to burners, if there are rivets/rings will be the first place to crack. as old as it is and heat stressed as it looks id be surprised if there wasnt at least a small crack. gaspacks are especially prone to hx failure bc the evap is before the hx causing condensation and rot

[@mrofnocnon]

Not tripping the roll out switch when you tried it as the door was off. When a rooftop has be running for some time, what could possibly cause the blower motor to reverse? Same with the slight gas overpressure, it's been that way for some time. I think I would have replaced the rollout switch as well as correcting the manifold pressure and also checked fan static pressures.

[@josephgarcia676]

That’s some funny looking stairs man I hear ya, I’m electrician. I’ve never seen that like that before I ever right on brother I subscribed.

[@HVACKnowItAll]

I appreciate it!

[@DanO181919]

Really like the short videos. Thanks for sharing!

[@HVACKnowItAll]

I like them short too, to the point haha!

[@joeschneider8025]

I had all them symptoms so I started replacing parts started with flame sensor then I tried pressure sensor and fixed it both parts cost me under $30 I'm just glad I didn't have a dirty coil or a vent clogged

[@HVACKnowItAll]

Those parts prvented a flame roll out?

[@jrh86]

Nice work 💯👍👍👍

[@Abuhummus]

Thanks for always putting out these informational videos. I appreciate it bud

[@HVACKnowItAll]

Thank you and no problem

[@agsmith001]

nice job! i had a water heater bust and flood next to the hvac and trying to dry the area tripped my rollouts = easy fix! thanks youtube!

[@daviddesilva4971]

Great diagnosis...keep up the great vids.

[@HVACKnowItAll]

Thank you!

[@bababooey7576]

A fellow GTA'er. Already subscribed. Thanks for the videos.

[@HVACKnowItAll]

Thank you!

[@navidd1971]

Outstanding. Fixed my problem.

[@justincanterbury2561]

Thanks

[@HVACKnowItAll]

My pleasure

[@connorpeacock4750]

Hoooooo Clarkson buddy you’re in my area !

[@jonathanraul4086]

Thanks nice video

[@HVACKnowItAll]

My pleasure

[@HughesManHVAC]

Well done 👍

[@HVACKnowItAll]

Thank you sir!

[@MrPro56]

Hey buddy today my furnace went out same flame rollout switch problem, had guy come to check says the pressure control valve assembly needs replacement because pressure is off. It would take almost a grand to replace and uncertain wait time for the parts. How did you change the pressure to make the gas control valve work again? The technician didn't even bother to adjust it and told me it needs replacement.

[@HVACRSurvival]

I wonder if snow cut off the combustion air vents? Or just a weak limit?

[@HVACKnowItAll]

Didn't snow really, maybe or hopefully the elevated gas pressure was just enough

[@HVACRSurvival]

@@HVACKnowItAll sometimes I'll mount a temp sensor beside the limit and put the covers back on and watch what the temp does, if no where near the rating I'll change the limit. That looks like the Armstrong I changed the draft motor on in a video I posted a while back. Old turd needs a good flush down the toilet😳😉

[@capitolrefrigerationheatin7501]

nice fix, would checking temp rise and total external static pressure be going overboard? I have had calls were someone closed diffusers or fire damper closed increasing total external static and tripping high limit.

[@HVACKnowItAll]

Yes of course if it tripped the limit, I would have checked that for sure

[@jasonlyons4484]

I had a Trane RTU a couple months ago where it would run ok but when I put on the door the flames would come back at me. It was -28*C on a Friday night, so I cut a hole in the door. Later I replaced the inducer and it seems to be good now.

[@HVACKnowItAll]

Nice, thanks for the share!

[@actechformallyyomama746]

Always check amperage on both legs of the induce motor. I had one that would explode like a shotgun. Turns out I was only drawing amps on one leg. This decreased the rpms and this caused the booming effect.

[@samuelhartness9855]

Do you ever check the heat exchanger with combustion analysis? It’s a method we use down south and it saves having to tear apart the unit to visually inspect the exchangers.

[@HVACKnowItAll]

Yes I do use a CA, but the only way to find a crack is to locate is visually.

[@samuelhartness9855]

HVAC Know It All but if your co ppm, o2% and excess air % are out of range that tells you the exchanger is cracked and you wouldn’t need to break the unit down to get a visual.

[@Abuhummus]

Samuel Hartness True.... what’s wrong with a good old visual? Sometimes this CA act up... just saying. I agree with both methods, I just don’t see anything wrong with a visual

[@HVACKnowItAll]

You could have those symptoms with plugged burner orifices or perhaps even RPM reduction in induced draft motor. I wouldn't trust a CA to tell me the heat ex is cracked myself

[@samuelhartness9855]

Yusuf Ata I don’t see anything wrong with it. It’s always easy to check on packs. But I work in residential so we have a lot of split units and it just wouldn’t be feasible to take the unit apart and inspect. A bore scope can only go so far as well, so we rely on the ca to tell us. That’s not to say that using the old method of sight and smell doesn’t happen. I’m just thinking in terms of saving time and using new technology to do more of the work.

[@HARE118]

Where are you located?

[@jake2213b]

How come you guys drive over an hour for a job. I can't get anyone drive 45 minutes. If they are not local forget it.

[@HVACKnowItAll]

I chose to live an hour outside the city 😆

[@ethelryan257]

My grandfather built up our firm against stiff competition to some degree because he was willing to work further out than the competition. Which my father did and I do and my two sons do, as well. Funny, but in over 70 years...not much has changed in that regard. We're still about the only firm which will do work out in the boondocks.

[@bert1913]

when testing for roll out, I leave the cover on

[@Mike-yh8tv]

Thanks for the knowledge.

[@HVACKnowItAll]

Thank you, thanks for watching

[@user-nt7gr4pp3b]

you over think it