Gas and Oil Home Heating Furnaces - Rheem blowing air but no heat

Hello all! I appreciate any help, and hopefully I'll give enough details below.

1. In which area you live and ambient temperatures you usually experience. --I live in central NC; temperature here this time of year is very much a mixed bag. During November it can be 70 one day and 40 the next.

2. House style and construction details.
--New construction, Cape Cod style, upstairs and downstairs heating and air units.

3. Make, model and age of equipment related to the problem.
--Rheem RRNA-B024JK06E. Unit shouldn't be more than 2 years old.

4. Fuel type.
--Natural gas.

5. Water temperature and pressures of boiler systems.
N/A

6. What type of zoning do you have with your boiler system.
N/A

7. Thermostat type.
-- White-Rodgers

7. Anything else that would be useful. No detail is to small. The more information you provide the easier it becomes for the professionals in this forum to determined the cause and correction to the problem. -- This is my downstairs unit. When I go to switch the thermostat from cool to heat (the A/C works fine), and adjust the temperature setting to 2 to 5 degrees higher than room temperature, no air comes out of the vent. I can hear a "click" coming from the thermostat as if something is trying to come on, but nothing happens. This is all with the switch on "Auto". When I turn the switch to "On", then air DOES come out of the vents, but it's cool air. I tried turning the thermostat off for about 20 seconds to see if that would reset it, but this didn't work. I went outside to the breaker box, and flipped the breaker off and on, but still no luck. I then went outside to the unit itself, and went to the fuse box that's off to the side. I made sure that it was in properly, pulled it out/in. When I did this, I could hear the unit start coming on, but the fan wasn't moving; wasn't sure what was happening. I looked the unit over for some sort of access panel, thinking maybe it was an igniter problem after poking around online, but opened up two panels and didn't see it. I looked online for a manual with some diagrams, but no luck.

I searched through these forums and didn't see anything quite similar, so hopefully someone has some insight. Thank you again!

The ignition control has a diagnostic light. What is it displaying?

I'll be glad to look...do you know where that might be, or should be? I didn't see somewhere on the unit to look for the ignition, and didn't have any luck online finding a schematic that might show me. I have a closet under the stairs, and the thermostat is on the wall of that closet (on the outside of course). Should it be somewhere in that closet around the wiring for the thermostat?

The light should be either on the ignition control or the furnace circuit board (sometimes one & the same). This board is often in the blower compartment with a small "window" in the blower door. Once you've counted the blinks, there should be a code on the control or on the inside of the blower door.

The fact you can make your blower work means nothing. The bottom line is your heating sequence is lost.

You say nothing about hearing the exhaust gas fan (called an inducer or ventor)coming on. That has to happen first in order for the ignition sequence to begin. First you need power from the thermostat to switch on a relay that allows 24 volt thermostat power to open up the 120 volt circuit to the inducer fan. Then if you have a 3-wire pressure switch, that pressure switch has to be in the normally closed position for that fan to start up. No fan, no ignition.

First confirmation needs to be that you are getting 24 volt power to go from the furnaces W(white) low voltage terminal, to C (common) or ground.

Thanks y'all...I'll check all of that (lights and voltage) as soon as I can tomorrow morning (almost 9 PM here) and report back.

You want to check to be sure that the thermostat isn't set to run the fan continuously by being set to "on, " "fan on" or some other setting that runs the fan continuously.



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Looks like an intermittent pilot ignition system.


I'm not familiar with this piece of equipment in particular, but it looks like you need to remove the right side front panel as pictured on page 25 to get access to the controls.

You probably need to remove a number of screws to do that.

This is also shown as the front service panel on page 26.

You are presumably going to find the ignition control with the diagnostic light where the arrow is pointing towards 13 on page 3.

What you are looking for is the "easily accessible control box" illustrated in #12 on page 3.



When you have the cover off so you can observe the burners---

Turn the thermostat all the way down.


Then turn it up so it calls for heat.

Carefully observe what happens in the burner compartment of the furnace section. You may need to repeat that a few times before you observe all the details.

Report back on what you see.

The venter motor ecman spoke of is the small motor above the gas valve (#10, page 3 of SeattlePioneer's pdf). With the power turned off at the breaker or disconnect, if you can see the fins of the motor or fan give it a spin with a small screwdriver. Sometimes these motors get stuck over the summer & once they are freed up they work fine for the entire heating season.