Thudding Noise coming from Pipes

[tdilweg78]

Hello,

I bought a house in May and I've been having an issue with the pipes/plumbing since I bought the house. Here is my situation:

When the well pump turns on, I can hear it turn on and I can hear a noise while the water is running. Almost like a fast ticking noise. When the pump shuts off, there is a very loud thudding noise (dud dud dud dud dud.... dud dud dud dud) coming from the pipes/system. I thought it might be just a loose pipe so I secured the supply pipe (from the well into the house) to the beams. This lessened the noise but it's still very loud. Also, lately the pump has turned on once almost every night for a week in the middle of the night when no water is running. So I ran a few tests:

1. After the pressure tank filled up with water and shut off, I ran water in my shower to see how long it would take the pump to turn on. It took approximately 6 minutes and 10 seconds of the shower running full blast to turn the pump on. This happened at 30 psi.

2. Then I turned the shower off and timed how long it took for the pump to shut off (causing the loud thudding noise) and it took 1 minute and 21 seconds for the pump to shut off. This happened at 60 psi. From what I've read this shouldn't be more than 20 psi from when the pump turns on. (20/40; 30/50; 40/60).

3. I pressed the valve at the top of the tank (I read that if the bladder has burst, water would come out during this process). No water came out.

I have a Flex Lite FL 12 35 gallon pressure tank. On the tank is written "3/4 H.P. Set at 300').

The only understanding I have on plumbing systems, wells and pumps is what I've read online. I know more now than I did before but I still don't know much. Is there anyone who could help?

 

[Valveman]

The ticking noise and the thud is a check valve problem. The above ground check valve should be removed and all the ticking and thudding will go away. However, the above ground check is probably masking another problem, which is the check valve down the hole is leaking back. Sometimes removing the above ground check valve will put more pressure on the down hole check and cause it to seal better. But if the water still leaks back when the pump is off, the lower check will need to be replaced.

At 30/60 that tank will hold about 12 gallons of water. So your shower uses about 2 GPM, and your pump supplies 10 GPM. When I see the pressure switch differential widened from 40/60 to 30/60, it tells me someone was trying to reduce the number of times the pump cycles on and off. This cycling on and off is what causes the check valves to fail. Cycling also causes the destruction of the pressure switch, bladder in the tank, start capacitor, and every component in the pump system, especially the pump and motor.

The 30/60 pressure switch setting makes the pressure in your shower go from a strong 60 to a weak 30 PSI. It also overstretches the bladder in the tank and shortens its life.

A Cycle Stop Valve will eliminate the cycling and give you a strong, steady, constant 50 PSI in the shower. This will eliminate the destructive cycling that destroys check valves and everything in a pump system, including the pump. And it will give you so much better pressure in the shower you will think the pressure is double what it was.

 

[JakeBin]

Another approach is to use a spiral of copper pipe. There are other options if this is a common occurrence throughout the plumbing system. You can also install a pressure-reducing valve on the water supply line for the house if the water pressure is very high (which may occur in low-lying areas).

 

[EdwardCantor]

A water hammer, free mounting straps, or excessive water pressure can make water pipes to produce thudding noise.

Occasionally a water hammer can happen during a pipe-mounting strap is free. These straps are of vinyl-coated nail-in hooks or can be metal plumber’s tape and hangers that connect pipes to framing. Check all open pipes to assure that they’re correctly and tightly attached.

 

[plumb_bob_square_pants]

Can you explain the copper spiral?

 

[Valveman]

Some people use a copper spiral of pipe going to the pressure switch, to keep the switch from seeing the water hammer and bouncing the pump on/off rapidly.

Pipe hanger and straps are how most people attach their pipe to try and keep it from swinging and bouncing from the water hammer.

Neither of these things to anything to stop the real problem, which is the water hammer. Water hammer is usually caused by the pump starting and stopping while pumping full flow. Start a pump or stop a pump from the max flow condition, and you will feel and hear the water hammer.

A Cycle Stop Valve will stop the water hammer by making the pump start and stop at a flow of only 1 GPM. You don't get water hammer when starting or stopping a pump while it is only producing 1 GPM.

I think this video shows a spiral on the pressure switch, and you can see the pipe swinging on the hangers. But all this goes away after the installation of a CSV.
http://www.cyclestopvalves.com/video/waterhammer-dsl.wmv