Random Noise in Pipes - NOT THE WATER HEATER
Not sure if you're keeping up with all my post. But if not see Random Noise in Pipes, Random NOise in Pipes - Expansion Tank, etc... Tonight we turned our water heater to pilot. And we still hear the noise. So now we know that it is not the water heater that is encrusted with junk. We know it is not the expansion tank. So, when we were in our utility room waiting to hear the noise we noticed that you can hear the rumbling in our ducts. We noticed that our furnace kicks on, then a few minutes later the fan starts, then the furnace seems to quiet down but the fans still goes, then the fan stops, and sometimes we hear the noise. I put my ear to the duct and you can hear the "Noise". Now, I can't say that it is the furnace or maybe our duct work is sitting on a pipes causing the noise to seem as if it is coming from the pipes. But we are just so lost. Does anyone have any ideas??????
Re: Random Noise in Pipes - NOT THE WATER HEATER
Your'e getting somewhere at last.
You have eliminated the WH, the PRV and the expansion tank.
It now appears that the furnace blower may have something to do with it.
You need to continue doing more of your own detective work on this, and it will cost you far less than having various tradesmen come in and guess at what expensive part they might be able to slap in and charge you for.
Continue the process of elimination by shutting off the electric power to your furnace. If you can do this while the noise is heard, so much the better--if the noise stops immediately, you know the furnace is involved. Just how it is making the noise will require more investigation. It may be due a duct touching a pipe as it vibrates, or it may be something else. Careful listening should lead you to the source.
When you find it, a simple DIY fix may be apparent, or it may need a professional's help at that point. At least you will not be wasting money on wild guesses.
Please post here with your progress.
NOTE: the reason your furnace ran and then quieted down after a time, was that, even after the burner and combustion blower shut off, the blower that moves the air into the duct system continues to run for a time as it continues to take heat off the heat exchanger of the furnace. This is normal.