Hello
We have a new construction home that is on a well system (submerged pump w/holding tank in basement). When the plumbing was done, it was configured for a water softener. (The hose-bib's are supplied by non-softened water).

The softener company that installed the twin tank softener put two brass swing check valves in-line, before the water softener pre-filter. Ever since the softener was installed, we are experiencing water hammer on our line, when the well pump shuts off. When I put my ear next to these swing valves, I believe the hammer noise is coming from there.

If I shut off the main valve in front of the swing valves (water softener inlet), and run my hose bib until the well comes on, it does not hammer upon shutting off.

Is the above described water softener configuration to code, or proper? I would like to call a licensed plumber out to fix it if the swing valves are not required.

I have a sketch of the system I could email as a JPG file if more helpful to understand our problem.

Ok, I'll take a shot at this. I have never worked on any well, water softener, or filter systems before so I'm going on theory alone here. It seems to me that your well tank was also acting as an expansion tank. Now that a check valve was installed after the well tank it can no longer work as an expansion tank, therefore you must install an expansion tank (small one) in line after the check valve(s). This will solve your problem.

Hopefully someone will chime in if I'm wrong.

From all the water softeners that I have installed on rough and on finish they are all 1 inch line. I'm not to sure I could be wrong. check and see if they make a hammer arrester in 1" and install it direct line of the service to the softener. I'm not to sure if they make a 1" water hammer.



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the swing checks could be replaced with a spring type check valve. I am really not to sure why two checks were installed but I would asume one would do the trick. You could also install a water hammer arrestor in line. Sioux chief is one company that makes them and I have always had luck with them.

Would a spring check be less prone to hammer than a swing check valve? I have NO IDEA why two were put in-line.

I have researched the Sioux-Chief Water Arrestors - if I install one, should it be "upstream" from the check, closer to the well pressure tank?

Thanks for your feedback, I really appreciate it as this hammering has been drivng me nuts - especially since it is very repeatable.

Please send a sketch
j_menacker@yahoo.com

Installing a water hammer arrestor may eliminate the water hammer but the source of the shock wave is still there. The earlier guess about where the holding tank is tied into the system is a critical piece of information.

A spring check valve might be part of the solution if everything else is connected properly. The spring assists in closing the check valve more quickly. This helps stop the reverse flow of water before enough velocity is acheived to cause the hammering.

Installing two check valves in series does not really do much more practical good than a single check valve. If possible, try asking the water softener company why two check valves are used instead of one.

Joe M in WV



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