Geothermal

Need Help! In my new home I installed a Geothermal unit that works great!! The unit basically takes water from my well cycles it through the goe unit and dumps it out into my pond. Heats and cools my house wonderfully! Now the issue I am having. The 3/4" copper that dumps the water out of the unit has a solenoid on it. When the solenoid closes it causes water hammering thoughout the pipe in my basement. As of Sat July 19th I added a water hammering arrestor on the 3/4" output pipe which seemed to work great for the first day. Now its back to hammering again, but not as loud. Any suggestions? Do the make larger water hammering arrestors? Please help!
Thanks
Matt

The cheep water hammer arresters don't work good in applications where the pressure varies and become a vacuum at times.

You want a bladder style hammer arrester, also known as an air tank.

You also need a lot larger water hammer arrester due to the length of pipe inside of the unit. it's like running a pipe 100's of feet.

Given the "pilot servo" nature of the valve, there is no way to keep it from snapping on and off. (it's not going to fail, it's just the way it's designed)

The water hammer is best added after the unit and just before the solenoid valve.

In addition to what Bill said, the type of solenoid valve used is also important. Some geo installers install the type that are used on sprinkler systems and a lot of them are fast closing and will cause a hammer. I have been using a slow closing type (300 series) made by HIT products in California with very good success ( no hammer ). Also if you have a well tank arrangement the pressure setting if set too high will also create more banging. These pressures can be lowered, but have to be set up properly and by a knowledgeable person.

A short thread in the Plumbing forum addressed the same issue, but the OP faded away...

https://terrylove.com/forums/showthread.php?t=22167