Loud knocking from basement

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ouch202

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Hi everyone, I'm hoping someone can help me out... This is my first post... Recently I have been hearing a random knocking noise coming from my basement.. It only knocks like two or three times, then it stops... and it'll do it again like maybe 5-6 hours later. By the time you realize it's doing it and you run down to see what it is, it's done. All I know is that it sounds like someone is banging on a pipe. Does anyone have any idea what this could be? We're not running water or flushing toilets or doing laundry or anything involving water when it does this.. I'm just at a loss.
 
Don't go into the basement!

Actually, it is common for pipes to expand and contract depending on heat or cold, and especially when they are not adequately secured in place. If you can pinpoint the sounds, either secure the pipe better or if they are not reachable, you could try the expanding foam in a can.
 
It just seems odd that this would just start after living here for over a year.
 
Yeah... All that is down there are the pipes, which seem pretty secure, a water heater, a toilet, washer, dryer, and my furnace. The furnace isn't even on, and it does it when the washer and dryer are off so I eliminated those two.
 
I would guess it is more of the house moving, than the pipes, since you are not using water when it happens. As temperatures rise and fall, the structure expands and contracts. If it is in the piping, it may just be a stud or joist rubbing against it during the expansion or contraction cycle.
 
we have ridiculously high water pressure from our line, so we have that the main valve that turns on/off your water only open like half way, to limit the pressure coming in. could some extra be coming through and making the pipes bang like that?

i hope it's not ghosts. actually, ghosts are probably cheaper. :)
 
I'm sorry but I don't know what that is. Could that be something that would cause a knock? I'm a woman who bought her very first house about a year and a half ago and plumbing isn't "exactly" my forte.
 
I had a broken sewer line a couple months ago and had to replace that.. yuckkkkkkkkkkkk!
 
I will be completely honest with you. As much as I dislike paying money to have an expert come to my house, sometimes it pays back several times over. We could throw out ideas, but it is similar to posting on a car forum saying, "I have a noise, what do you think it is?" If I were in your shoes, I'd pay a local reputable plumber to come over so you could explain your concerns, and he could check the knocking and also determine if a pressure regulator is necessary. If this is not possible, we will be here to help you in any way possible. Also, please keep us informed in order to help others with the same problems.
 
That's true.. I have a family friend that is a plumber.. I hired him to fix my broken sewer lateral, so I'm hoping that he can come up and take a look at it for me. I'll let you know how it turns out.
 
Had my plumber friend come over... Naturally my noise didn't occur while he was here, but he checked everything out. He discovered that my basement toilet wasn't fully shutting off, so he fixed that.. and he discovered that one of the pipes on my boiler is leaking water (The backflow preventer apparently). He also said I have the highest water pressure he's ever seen in a house ever. We actually have the main valve turned down like i mentioned before, because the entire house vibrates when it's turned up. He turned that and heard the vibrating. Turned it back and gave me instructions. He said I am first to get my furnace serviced so they can fix that backflow preventer from leaking water (he said my high pressure is probably what caused that to break), and then I am to contact my water company about either a) turning down the pressure to my house at the main line, if possible. or b, If not possible he said said that I desperately need a pressure reducer. He said that he can do that, but that I need to go through them first because it may be something that they could do for me. After he left, it knocked two little times... which is better then the 4 or 5 times that it's been knocking recently.. so whatever he did to the toilet seems to have helped at least a little.. maybe it just needed to get that little burp out of its system. We'll see if it does it again. He said if my house keeps knocking i need to sell it and move closer to home as he drove like 45 minutes to come out and look at it. Lol. I'll let you guys know what the water company says and what is the result after that.
 
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It sounds like you are on the right track to fixing the problem. Thank you for keeping us informed!
 
I went a little out of order, I e-mailed the water company tonight. They are usually pretty good about getting back to people. I'm hoping it's something they can take care of. I'm going to call the furnace people in the morning. He told me not to call them after 3:30 because then it's probably considered an emergency call and will cost me more.
 
The water company got back to me today.. They do not install pressure reducers however they said they checked my house and my pressure is over 100 PSI and that they highly recommend having one installed. They said they just recently took over the water from another company and assumed everyone in this area had one installed already. The furnace people are coming over tomorrow morning. Do you guys have any idea how much it would cost to install the PRV?
 
Most regulators can be purchased at a local big box hardware store, and cost ~$50-$120. Depending on the type of pipe you have, the access to the pipes, and the service costs for a plumber, it would probably cost somewhere between ~$200-$400. I would contact a few plumbers in the area (less drive time = less costs) and ask them what they would charge.

I personally would be more persistant and recontact the water company. Ask to speak to the supervisor and tell them their excessive water pressure is causing you problems and what they could do to make you be a satisfied customer.
 
I don't mind paying for it.. I've had some dealings with the water company before and they have honestly have been some of the nicest people I've ever had to deal with on the phone, so I'd rather not piss them off. They probably think I'm a moron based on some of the things I've done but oh well. (I pay bills online and I'm queen of sending them my electric bill payment and then needing them to refund it to me, haha.) They even send out a letter after every interaction asking for feedback on the service they provided. I work in customer service myself, so I know how bad people can be (I'm sure you guys are aware of this, haha) so I really appreciate the way they go about it. I e-mailed them about this at midnight last night when they were closed and the girl called me back promptly at 8:00 AM, I think that is when they open. She genuinely sounded so alarmed by what I had put in my e-mail. She called like four diferent people for me to see if there was anything they (the company) could do. I'm fine with what she said.. I just want it fixed.
 
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