Crazy Banging Noise - Service Hasn't Been Able to Fix for 3 Years

[dmfelder]

I have a problem that has persisted for several years. Each year, a service guy tries another solution. The heater bangs like crazy, and it's not the ductwork. We have cleaned it, replaced the mother board, checked the gas pressure, checked the voltages, cleaned the flame sensor, and replaced the gas valve/solenoid, to no avail.

Here is a video I posted online. It's pretty dramatic. Any ideas? (I had to slightly edit the link because I haven't posted 15 times and this system wouldn't allow me to post a valid link...just remove the space.)

garmentdeli .com/Furnace_Banging_Noise.wmv

[HayZee518]

need a bit more information on your heater. make, model, type of ignition [ spark or hot rail] flame sensor [ flamerod or photo cell] is your blower motor connected to the squirrel cage by a belt or is it directly fastened to the motor shaft. have you checked if the fan is hitting the fan shroud? is it out of round?

[dmfelder]

It doesn't bang all the time, either, which makes has made it difficult to diagnose (and the tech can't wait around all day). And, as luck would have it, it tends to bang all night.

There IS a humidifier on the system. A friend thought it could be related to the heat-exchanger, but offered no further advice.

The furnace is a Rheem RGRA-12ERAJS
Rheem Classic 90 Plus Premium Efficiency
Board part number: 62241140-02 (model 1028928)

It has a "General Air Bypass Humidifier"
RCBA-4882GG24


Sometimes, when I'm just standing near it while it's functioning, watching the flames through the little window, it "puffs out & extinguishes." Literally, the upper panel pushes out a little bit and you hear a slight "swoosh" sound.

We've literally gone through what appears to be standard protocol with the diagnosis. We've replaced everything obvious, and checked voltages, gas pressure, etc.

It's a spark ignition, and it has a flame sensor rod.

As for the noise as it relates to the fan or any other moving parts, it's banging before the fan engages. It's banging while trying to ignite.

[dmfelder]

More information:

First, I'm in Chicago if anyone wants a look-see. If anyone knows the local "Rheem Master" in Chi-town, please let me know.

It's quite random, but I seem to notice it more in the middle of the night. And when it DOES bang, sometimes it's only once or twice. I had a camera on a timer for quite some time because no one would believe me when I described how bad it was.

Here's another thing, although I'm not sure it offers any clue:

I'm in a two level home. The heater is below me (sub-grade) and about 20 feet south of my bedroom. There is a gas line that extends under my bedroom and through the back wall of my home (presumably for a natural gas grill). My bed is against the exterior wall. From my bedroom, it sounds like someone is hammering outside, just on the other side of my bed. In addition, I can hear it somewhat prominently in the kitchen (gas stove). So, it's clear that the pipe is acting as a conduit of the noise throughout the house.

This may be obvious to you "HVAC gurus" but the fact that the noise is traveling through the house along the pipe might give you some more insight to its origin.

[paul52446m]

More information:

First, I'm in Chicago if anyone wants a look-see. If anyone knows the local "Rheem Master" in Chi-town, please let me know.

It's quite random, but I seem to notice it more in the middle of the night. And when it DOES bang, sometimes it's only once or twice. I had a camera on a timer for quite some time because no one would believe me when I described how bad it was.

Here's another thing, although I'm not sure it offers any clue:

I'm in a two level home. The heater is below me (sub-grade) and about 20 feet south of my bedroom. There is a gas line that extends under my bedroom and through the back wall of my home (presumably for a natural gas grill). My bed is against the exterior wall. From my bedroom, it sounds like someone is hammering outside, just on the other side of my bed. In addition, I can hear it somewhat prominently in the kitchen (gas stove). So, it's clear that the pipe is acting as a conduit of the noise throughout the house.

This may be obvious to you "HVAC gurus" but the fact that the noise is traveling through the house along the pipe might give you some more insight to its origin.

This is something that does not happen very often, in fact i have only seen it three times in 40 years. Out side your home is the nat. gas meter and regulator The regulator has to take the pressure from street pressure which might be 60 pounds, down to 1/4 pound going into your house. This regulator has a shaft and plunger that moves up and down to maintain the pressure.
I have seen new and rebuilt regulator do this. The cylinder walls that the shaft go up and down is not sized right so some times it chatters sideways as it goes up and down. This will make bad banging all through the house.
Print the out and call your gas co to change the regulator . Don't back down , make the change it. This can make you furnace puff out at time because the pressure is not being maintained. This can be a very dangerous condition.
Paul

[dmfelder]

I'm not sure this is the case. I am 99% certain that origin of the sound is at the furnace. It is louder there than anywhere else in the house, and I can feel it if I touch the furnace while it's happening.

[paul52446m]

I'm not sure this is the case. I am 99% certain that origin of the sound is at the furnace. It is louder there than anywhere else in the house, and I can feel it if I touch the furnace while it's happening.

Your descriptions were very good When you told me you could here it out side your wall in the bed. Your gas lines can be slammed with hi pressure and that will make them hammer. It can damage your gas valve blow the main burners out.
If you told me that this happens when the furnace is getting hot then i would say it could be in the heat ex changer. .
I had a Rheem furnace that i put in new, and customer call in two days later and said it was banging. When i checked it out , it was doing it when it was heating up and it did bang hard. i call rheems and they told me to bake the heat ex changer, by jumping the limit, take out the blower. Well i will not do that to the customers new furnace so call rheem the next day and told them it did not work so they sent me a new heat ex changer and that fixed it.
One other thing to check is are all burners firing every time . If one burner does not fire then it might build up gas and blow. Are your stacks out side done the way the book tells you to do it?. I still think you should change the regulator. Paul