Heating stopped working

[Edgar Miller]

Hi Guys,
I'm back. Sorry for the delay but I was busy with some other things in my wife's vegetable garden (springtime in Texas).
I tried to open the unit (btw, it's a Rheem Criterion II furnace) but, for the life of me, I couldn't pry it open.
However, I managed to finally find the installation manual (over 50 pages) and I'm studying it right now.
Luckily, the winter seems to be over in our neck of the woods so we don't really need heating, but, of course, it needs to be fixed.

 

[Reach4]

I don't know your furnaces, but mine have had to be lifted up before pulling out.

 

[Sponsor]

 

[Edgar Miller]

I've tried that too and I can't get it open.
The install manual doesn't mention it.
I've sort of given up. Will call in the cavalry when the heating period arrives in fall.
Thanks for all the input.
Ed

 

[Reach4]

Will call in the cavalry when the heating period arrives in fall.

A dedicated procrastinator I see.

Looks like this?

If so, what are those circles in the top corners of the top panel?

 

[Edgar Miller]

Son of a gun! Got it open.
Here are 2 pics.
Hope they help.

 

[Edgar Miller]

Guys,
I guess the 2 images did nothing to enlighten anyone of you professionals.
What can I do next?

One other question, some of you, I'm sure, will find a silly one: where in the world is the AC part of the unit? The installation instructions only talk about the furnace, not a single word about the AC.

 

[WorthFlorida]

You have a finance first and the A coil is usually placed on top of the box so it sits on it. This installed horizontally so I would guess the AC coil in on the left in the duct work. That appears to be a condensate line on the left. but it can be for your furnace and or AC. A few more pictures further away would confirm it. However, just looking at it no one can say what is wrong and it could be one of many reasons . Being a gas fired unit, as you said, call the calvary. There is a large catch pan under it.

Furnaces have the fan motor before the plenum that pushes the air through the box (before the flame), AC air handlers pull the air across the coils and it is on top part of the box.

 

[DonL]

Guys,
I guess the 2 images did nothing to enlighten anyone of you professionals.
What can I do next?

One other question, some of you, I'm sure, will find a silly one: where in the world is the AC part of the unit? The installation instructions only talk about the furnace, not a single word about the AC.

It may be best to have a pro look at it for you. There are many safeties on that unit that can keep if from running.

Do you hear the vent motor running when the T-Stat call for heat ?

 

[Edgar Miller]

I'm not sure what the vent motor is.
Is it that fan that forces the warm air through the ducts?
No, that one does not run.

 

[WorthFlorida]

I'm not sure what the vent motor is.
Is it that fan that forces the warm air through the ducts?
No, that one does not run.

That is the exhaust fan for the gas burner. The blower for heat and cool is on the right.

 

[Edgar Miller]

Is that the fan that is turned on at the thermostat?
That one runs when I switch the tstat from AUTO to ON but it does not run when I call for heat.

 

[WorthFlorida]

This is a basic way these furnaces work:
When the system calls for heat, the exhaust fan (direct vent) turns on by the control board inside the furnace, the gas valve is opened and a pilot light or a spark lights the gas. After a certain amount of time is past to allow the phemum to heat up, the big fan turns on. If the exhaust fan doesn't run, nothing else will. If the exhaust fan runs but no heat is detected after a certain amount of time, the gas valve is shut off and the big fan won't run. The FAN switch at the thermostat bypasses everything and it manually turns on the fan.

By your questions I'm afraid to explain how the thermostat works for heat, Too much liability here. This forum helps those who are in a jam and needs to ask knowledgeable questions, not a teaching class for beginners with gas. An AC air handler with electric heat is much safer to walk someone through troubleshooting.
LOL

 

[Jadnashua]

If you have or can find a copy on-line, read the theory of operation that's usually in the installation/operator's manual for your unit. THen, you can (maybe) have a better idea of how it runs, and what may be wrong.

As they get newer and more efficient, there are more parts and those must all operate properly. TO determine that, there tend to be numerous interlocks and safety devices. Some boxes have error messages or error lights, of which some will flash out a code if they aren't dedicated fault lamps. THat can help diagnose your problem, if they exist and you know how to interpret them.

The schematic can help those that understand them to troubleshoot the problem, but that also requires some knowledge and test tools. OFten, that takes hands-on at the location.

 

[DonL]

Is that the fan that is turned on at the thermostat?
That one runs when I switch the tstat from AUTO to ON but it does not run when I call for heat.

No. Different motor. @WorthFlorida described very nice.

One thing that you may want to try, That is safe and easy ;

Turn the breaker(s) OFF for both the inside and outside units to kill complete power to the system.

Then after a bit, Turn the breakers back on. Then try again.

Sometimes the controller can get a "Brain Fart" and needs a Cold Start, From power cycling.

If that does not work, You should call a pro for help. Where are you in Texas ?

Gas is very dangerous to play with. That is why all safeties must work. Including the side door needing to be in place.

Good Luck.

P.S. Did you pay your gas bill ? Lol. Just had to ask...