I had a 1/4in line run from my basement to a new kitchen refrigerator, using a saddle valve coming directly off the 3/4in main (it's the first tee off the street essentially).

Every time cold water shuts off in the home (whether it's the kitchen or bathroom sink, or the fridge's water dispenser) there is an audible shake and bang from behind the fridge, I am assuming the 1/4in is vibrating against something. I have amazing (A M A ZING) water pressure in my home, best shower I've ever had, every day.

So I'm going to pull the fridge and brace the copper pipe, but there has to be something else going on here, this doesn't sound normal. I am worried about the lifetime of this pipe and my wood floors. Do I need to reduce pressure somehow? Even if I brace the heck out of it, something is causing it to buck and that's bound to affect something, somewhere.

  • What is the water pressure in your house water supply? Does the city supply water at a higher pressure than is optimum for a house and depends on customers having a pressure regulator? Do you have a pressure regulator to reduce the city water supply to the proper value for a house? – Jim Stewart Nov 3 '17 at 23:29
  • I do not have a pressure regulator in the house, it was built in the 1950s and I would assume that would be here if needed, but I will check with the water co - good idea. I could 'turn down the knob' at the street if I had to, but my wife loves her showers so there would have to be a compelling reason. I am unsure what the actual pressure is, but I've had a few plumbers say 'whoa'. – mikewaters Nov 3 '17 at 23:31
  • We have no audible water hammer in our house from shut off of any manual valves, toilets, washing machine, or ice maker. Dallas states that they guarantee water at a minimum of something like 30 psig (!) but they say typically it is at about 50 psig. At one point I put an inexpensive timer on an outside faucet and got a significant clunk from the flexible line on the kitchen faucet. I guess this was the combination of high flow and a rapid cut off. – Jim Stewart Nov 3 '17 at 23:38
  • You should NOT turn the water valve to a less than full on position. This would cause turbulence and wear in the valve. This would restrict flow and cause pressure to drop under flow. – Jim Stewart Nov 3 '17 at 23:41
  • You say you have amazing water pressure, but since you are basing that on the flow in your showers, you may just have shower plumbing and shower heads that allow a high flow. Modern codes require shower heads that allow no more than 2.5 gal/min (at time of sale), and "water saving" heads restrict flow to less. Ultra low flow heads restrict flow to 1.0 gal/min. Professional plumbers are not allowed to remove the internal flow restrictors, but there is no legal sanction for the homeowner doing so. Some low flow heads do not work with some tankless water heaters. – Jim Stewart Nov 4 '17 at 9:37

You probably have always had the problem but adding the T made the problem noticeable. As far as I see this there are 2 problems. First the plumbing is loose and needs to be secured you may have not heard it in the past but it was there adding the T may save your plumbing because now you know it needs to be anchored. 2nd be prepared to replace the saddle valve these things are trouble waiting to spring a leak at the worst possible time according to Murphy's law. Do you need to lower the pressure NO! Pipe movement is a flow issue pressure can make it worse but why sacrifice wonderful water pressure when all that is needed is to anchor the pipe.

  • I agree that using a saddle valve is not the best way to add a line, it's a leak waiting to happen. I do not agree with stating that pressure does not have to be lowered, it is totally dependent on what the pressure is (OP has not given that info). Using regulators to lower the pressure is very common. – Jimmy Fix-it Nov 4 '17 at 4:35

You have what is known as Water Hammer. You are hearing it behind the fridge because that line is not secured like the others in the home. The best thing to do is to install a pressure regulator for the home and an arrestor for the home. While you can get by with just an arrestor - if you are able installing a regulator at the same time will protect the pipes in the home from over pressure.

Now you can install these arrestors on individual lines as well - such as washing machines and yes the refrigerator line - I would recommend you install it for the whole house - which would take a different unit than the one shown in the picture below - you can search online.

Some links below - not an endorsement of any company or product - just a link.



Example - Sioux Chief Mini Arrestor

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