I would need to look at installation and owner's manual to accuratly answer but you can do that yourself.

Lockout switch on the access panel?

On occasion I've found some furnaces love to get their belly rubbed before willing to commit to a burn cycle. (True stories)

So if the panel you're removing isn't connected to the blower door switch, your guess might be better than we can provide you with from a forum board.

In the back ground there's someone behind the back of another that is shutting the furnace off by lowering the temp. (suspected not proven)

Until you can prove it? conspiracy theories from the HVAC [cold case] Dept.

I service the Katy, Texas area. (in person)

I like the X-Files approach mate!

The door is literally just a metal cover but there is a clear lense set into it that does... something. It's only an issue at extreme temps and doesn't appear to pose a threat.

Thx for the reply.

Is this Carrier 59TP6B Performance? As shown on page 3, there is a blower door safety switch that prevents the furnace from operating when the door is opened or removed. Perhaps the switch loses contact with the door when it is extremely cold and you could move the switch closer to the door (for example, if it's held in place by a bracket you could loosen the bracket, slide the switch closer to the door, and re-tighten the bracker) so this doesn't happen.

Yup, that's the one. Cheers for this I will have a look.

It's a condensing furnace so it's possible it might be condensate trip related would be my suspicion... Probably best to call your installing contractor and have a maintenance check performed on it.

If it were me I would wait until it trips again, then don't touch it and have your installing HVAC contractor check it out.

@Austin Air Companie: "It's a condensing furnace so it's possible it might be condensate trip related would be my suspicion"

Page 16 shows the furnace wiring diagram. The three wires from the thermostat for heating are W, C, and R. Y/Y2 receives power from the thermostat during cooling. In any case, where is the switch in the furnace that would turn it off due to "condensate trip"?

Appreciate all the input. Time for a service call for sure.

wdccruise,

Sorry, you got the wrong guy. I'm here to do it for you, not tell you how.

There are trade schools for that.

I service the Katy, Texas area.

@Austin Air Companie "Analyses"

1. "some furnaces love to get their belly rubbed"
2. "someone behind the back of another that is shutting the furnace off by lowering the temp"
3. "condensate trip related"
4. "I'm here to do it for you, not tell you how"
5. Dunno.

And that completes the full spectrum.

You never answered @wdccruise's question, Ray. Or would that require paying for a service call?

You've never answered any of my questions Charles.

You're a builder aren't you Charles? You hire mechanical HVAC contractors to do HVAC work don't you?

"With a condensing furnace...the combustion exhaust gases are also passed through a secondary heat exchanger that absorbs much of the remaining heat from the gases. As the gases cool, they condense to form water and carbon dioxide... The water...drips out through a drain pipe..." -- A Visual Guide to a High-Efficiency Condensing Furnaces

"Failure to Ignite Caused by a Clogged Condensate Drain

"...ignition problems on a condensing furnace may be related to a clogged flue vent condensate line. A partially clogged condensate line, or a clog at the condensate collector box near the inducer fan, will often trip the furnace’s pressure switch.

"If the condensate drain is blocked by debris or frozen condensate, or if it simply drains improperly, the pressure switch may open, preventing ignition. Because the pressure switch senses the accumulation of condensate in the furnace drain pan, the furnace will not operate until the condensate drain has been cleared and the condensate can again flow freely." -- 5 Common Problems With High-Efficiency Furnaces

But the OP stated that simply opening and closing the blower door restarted the furnace.

It literally is just open door, close door. Hasn't blinked since the temps went up to near 0C which is normal here for the season.

"Hasn't blinked since the temps went up..."

Which to me would indicate it's not a condensate drainage problem. However if the shutdown occurred while you were away it could be disastrous: burst pipes and the resulting damage.

Agree at wdccruise. Likely due for a maintenance cycle anyway so that's motivation enough to have it diagnosed. Cheers.

But the OP stated that simply opening and closing the blower door restarted the furnace.

This is why the furnace needs to be inspected in person. The odds because what type of furnace it is and the age thereof puts the odds on a problem with condensate.

You will always need a good HVAC contractor that identifies problems in person. If you want to pretend to work, pretend to work some where else.

In order to be a legend, you must do legendary things. I don't consider pretending one of them.

Could it be something other than condensate problem? yes. again why you investigate in person.

When the furnace door is open, is there an error code display on the control board? If there is the Carrier documentation will indicate the possible fault condition. That may help the HVAC tech diagnose the problem.

I think this problem could be due to a malfunction of the electronic control system. This is a possible root cause without seeing any photos or being on site.

Condensing furnaces typically have air intake and exhaust PVC pipes going out the side of the of house. These pipes can allow cold air to enter into the furnace and lower the ambient temperature around the control board. The microcircuits used in furnace control are usually rated to operate in the 0 - 70 C degree temperature range. When the outdoor air drops below -20 C degrees, it is possible the control board is below 0 degrees and cause the electronic control to malfunction and not to start the furnace when the thermostat calls for heat.

Opening the blower door and then closing it immediately causes a temporary disconnect of the power supply. Control boards will usually have a power on reset circuit. The temporary power interruption resets the board to a known state and allows the control function to start the furnace and the heating cycle.

When the temperature is above -20 C degrees the control board is within the design temperature and the problem does not occur.

TTR

Thanks Mike. This is the most plausible explanation I have read. We don't often plummet to temps that low for long so next time it happens I will pull the code and look it up. What you describe is spot on though. Appreciate the thorough reply.

T

@mike_home: "Condensing furnaces typically have air intake and exhaust PVC pipes going out the side of the of house. These pipes can allow cold air to enter into the furnace and lower the ambient temperature around the control board."

The diagram on page 3 of the furnace Product Data shows the control board in the blower motor section of the furnace whose temperature would be far above -20 degrees. How could cold "combustion air" ever reach a control board placed in this location as you have described?

@wdccruise

Sorry I can't answer your question. I proposed a possible root cause based the presence of low temperature and resolution by opening the front panel. I have found nothing should be assumed when trying to solve an unusual problem.

But then again what do I know. I'm just a homeowner living in NJ who never graduated from HVAC trade school.

When the temperature is above -20 C degrees the control board is within the design temperature and the problem does not occur. ~mike_home

That would really make for a great story mike... We're so sorry it's just too cold for you gas furnace to run. Wait for it to warm up??

Seriously? Yes, when we make furnaces we design them to not work when you will need them the most?

So I looked for a few seconds... operating temp -40C to 80C operating range for an off market goodman control. You bought a high end condensing furnace and you can't run it because it's too cold?

click to enlarge

Thanks for the laugh Mike.

Ray,

Is the control module you have shown the same part number as the one used in the 2 year old Carrier Performance Series furnace being discussed in this posting? While you are researching that check the country where it was manufactured. I was not aware Carrier continues to use parts manufactured in the USA for their residential Performance Series furnaces.

@Austin Air Companie: "So I looked for a few seconds... operating temp -40C to 80C operating range for an off market goodman control."

That's not this furnace's control board.

https://www.youtube.com/watch?v=i2nfnX5NT1g

@wdccruise

How could cold "combustion air" ever reach a control board placed in this location as you have described?

Your question had me thinking about this a little further. We know there are sensors which relay information to the the control board. Some of these sensors are closer to the cold combustion air source. Perhaps one of these sensors is sending erroneous information to the control board and causing the embedded software to enter a state it was not designed to handle. Metal and plastic conntract as the temperature drops. It could also be an intermitten connector causing this behavior at low temperture.

The old adage "when you hear hoofbeats think horses, not zebras" is always good to keep in mind when troubleshooting. The fact that the problem is consistently remedied when the furnace access panel is opened and closed suggests an issue with the access panel limit switch as wdccruise has clearly and logically outlined above. Eliminate potential simple causes before looking into more complex ones.

I'd temporarily bypass the safety and see if the furnace continued to operate when the outside temperature was very low.

"...bypass the safety SWITCH..."

Be sure to listen to what all these pros are telling you... your furnace was designed to fail when it gets to cold outside?

Be sure to watch the video to it's entirety that wdccruise posted to get to the bottom of the problem of this furnace?

You won't find any useful information there in the video... it's a video geared to selling you the furnace.

Let's not think about any of this. These are the troubleshooting skills of a forum board.

I service the Katy, Texas area. (In person you can accept substitutes - but I don't recommend it)

@Mongoose Salty

When the temperature is below -20 C and the furnace does not start the heating cycle, do you recall seeing the flashing error code LED through the lens? If the aswser is yes, then that would incidate the furance is still receiving power and the door safety switch is engaged. If not then the safety switch could be at fault.

@mike_home Sadly I do not. I didn't know to do that so I just popped off the panel (as if I knew WTF to do next) then put it back and 2 sec later the motor fired up and it ran a cycle.

It is pretty rare we get any sustained temps where I have noted the issue (>-20 seems to be the trigger) so I will be sure to note any error codes next time.

Appreciate the input here but do y'all squabble this much on the regular? Seems counter intuitive in a help forum.

Unfortunately there are some regular posters who want to spend more time criticizing othes rather than offering helpful comments. This seems to be happening more often in this forum.

"That would really make for a great story mike... We're so sorry it's just too cold for you gas furnace to run. Wait for it to warm up??

Seriously? Yes, when we make furnaces we design them to not work when you will need them the most?"

What is it they say, ROFLMAO ? Could I sell you a heat tape to go along with your new furnace ma'am?

@Austin Air Companie: "Be sure to watch the video to it's entirety that wdccruise posted to get to the bottom of the problem of this furnace?"

The photo is of the control board in this Carrier furnace. The purpose of including it was to make clear that the ICM control board you yammered about had nothing to do with this furnace. I didn't say watch the video. But you service Katy, TX so that counts for something.

@klem1: "Seriously? Yes, when we make furnaces we design them to not work when you will need them the most?"

Huh? Mike suggested he check for a control board error code.