New furnace making noise, but not blowing!

Printable View

11-05-2009, 09:19 AM
Richster

New furnace making noise, but not blowing!

Hi,

I had a new Goodman GMH95 furnace installed in my home on 16 October of this year. Everything worked fine for a couple weeks, and the weather warmed up so we haven't had to use it the last week or so.

Last night, the temperature dropped a bit, and we turned the thermostat up a few degrees to warm the place up. The only problem is that the heat never turned on. I kept it 5 degrees higher than the current room temperature for 30 minutes and it never came on.

I went out to check on the heater, and it seems like the thermostat is kicking in, and the heater is turning on (it's making noise, and I believe the pilot light is burning), but the fan never kicks in to force the hot air inside. After about 5 minutes of making noise, it stops. Then it start again a few minutes later, doing the same thing.

I can hear sounds at the intake/exhaust port,and I hear sounds from within the furnace that sound like the pilot light, but I can't tell if the burner is firing up. And I know that the fan isn't turning on.

I'm having a technician come out tomorrow morning, and it's still under warranty, but what could be the problem?

Busted fan motor? Or something else?

Is the fan and motor contained inside the furnace unit? Or is it in my A/C equipment? I hope it's the former, because that's covered in the warranty. I didn't have the A/C coil or any of that equipment which sits on top of the new furnace unit replaced. Here's a picture.

http://i15.photobucket.com/albums/a4...e/IMG_2105.jpg

http://i15.photobucket.com/albums/a4...e/IMG_2106.jpg
11-05-2009, 12:42 PM
seanddd

This is the burner trying to turn on, after several tries, it gives up. Through the clear round window on the bottom half of the unit, you will see a red LED light, is it blinking or steady on? What's the blinking pattern? I don't want to guess the problems, the hot surface ignitor definately works. Did you turn on the gas ball valve on the gas supply line (kinda stupid to ask, but it does happen to HO)? If you can hear the gas valve open but no flame, you know you don't have gas flowing in, the pressure switches are all good, otherwise it won't let the HSI to turn on and gas valve to open.

blower won't turn on if the flame/temperature are not detected.

How old is the AC coil? it looks pretty rusty old.
11-05-2009, 01:14 PM
Richster

I saw the red light last night, but I'm at work right now so I can't tell you exactly what it's doing. I turned the system off just to be safe while I'm at work all day.

As for the gas ball valve, I haven't touched it at all, so if the heater was working two weeks ago, I'm going to assume that it is still in the correct position. No one has been in there except for me, and I didn't touch it.

Thanks for the tip, but I'm not going to do this myself while I'm still under warranty. They are coming out to look at it, and I'd rather not screw something up before they get there. :oops:

I'll take another look when I get home and take a peek in the manual, and post back if I see anything interesting or confusing...
11-05-2009, 01:23 PM
Richster

Did you edit your post a bit? I missed some of those questions.

Quote:

If you can hear the gas valve open but no flame, you know you don't have gas flowing in, the pressure switches are all good, otherwise it won't let the HSI to turn on and gas valve to open.

I didn't know to listen for it last night. I'll check it out when I get home.

Quote:

blower won't turn on if the flame/temperature are not detected.

So that could be a faulty sensor or something, right?

Quote:

How old is the AC coil? it looks pretty rusty old.

Ha! Considering the furnace I replaced was dated 1978, it's a good bet the AC coil is at least 15 years old, if not more. Not in the budget to replace it this year, though :(
11-05-2009, 01:54 PM
seanddd

[QUOTE=Richster;4949752]Did you edit your post a bit? I missed some of those questions.

Yes I did, some of my previous thoughts were invalidated by some later ones.

So that could be a faulty sensor or something, right?

SHouldn't be, since the HSI turns on (some red glow in the upper cabinet for 5-8 seconds, is there?), means the unit is ready to ignite, only to find out no gas, no flame, time to go back to sleep... hate to guess a faulty gas valve.

Ha! Considering the furnace I replaced was dated 1978, it's a good bet the AC coil is at least 15 years old, if not more. Not in thebudget to replace it this year, though

We are in Horsham PA, if you need help in the future...
11-05-2009, 04:34 PM
diverdan

Just call the installer. It's under warranty so make them come fix it for you. They should give you at least 1 year labor so quit guessing and have them fix it. Then tell us what was wrong :)
11-05-2009, 05:53 PM
seanddd

It's totally normal for people to have discussions on what could be wrong. We should all at least have a reasonable level of curiosity, otherwise we will never gain any knowledge about anything.

Quote:

Originally Posted by diverdan

Just call the installer. It's under warranty so make them come fix it for you. They should give you at least 1 year labor so quit guessing and have them fix it. Then tell us what was wrong :)
11-05-2009, 09:36 PM
DavyB

Your IDM is spinning backwards.
11-05-2009, 10:22 PM
threadcutter

Look for the flashing diagnostic light

Gas furnaces have a diagnostic module located on the fan control board or the ignition control module. You will find a flashing light. Count the number of flashes, then look on the back of the blower door or burner compartment door for a legend that defines what the flashing light means. If the legend is not on the machine look in the install manual.
You can try turning off the power to the unit and waiting a few minutes then turning it back on. Sometimes this will clear the fault if it is related to a recent power interuption. Your situation does not sound like that will help. In any case it will be in your best interest to contact your service person. Your furnace is still under warranty.
Good luck.
11-09-2009, 09:11 AM
Richster

Thanks for the replies. And yes, this was more for the sake of curiosity and discussion. I did of course have the installer come out and inspect the unit.

According to his trouble report, the pressure sensor tubing was rubbing against the inducer motor, and it got worn through. This prevented the blower from turning on.

He replaced the tubing and re-routed it so that it wouldn't happen again. He also double-checked everything to make sure nothing else would be making contact with the motor.

Took him all of 15 seconds to diagnose the problem. Heat is working fine now :)
11-10-2009, 04:48 PM
lentz

No Heat

It's great to have a good teck that knows what he is doing.
Have a warm winter. And Happy Holidays