2-Gallon Mini Thermal Expansion Tank, Stainless Steel Hammer Arrestor with 1/2 Inch Threaded Connection, 60008

I put this on the input to the pressure regulator to absorb the water pressure surge when the pump comes on. It keeps the pressure switch from hammering on and off.

I never knew that this product even existed. I found out about it bought it. Had it installed and I've been so happy. I got approved by the inspectors immediately building and safety. This is a must have for a tankless water heater.

Work just for what I wanted it for. Used on washing machine to stop water hammer.

This micro expansion chamber is marketed principally for thermal expansion protection of in-line tankless or on-demand water heater systems, which it should be great for. A secondary use is for water hammer reduction, which is what I purchased it for. Pros include the fact that it is made by Eastman, a reputable supplier of thermal expansion protection products. I have a full size unit to protect my tank-based water heater system and have been very pleased. This micro-expansion chamber exhibits the same quality. Pros: good manufacturer; straightforward installation requirements; stainless steel construction. Cons: no installation or service instructions; incorrectly listed in the product description as having 2 gallon capacity (this is incorrect - it is meant for 2 gallon capacity tankless water heater systems but the chamber itself is likely about a cup in volume). As mentioned by another viewer, setting the pressure is very difficult. There is so little volume in the air-portion of the unit that getting the right pressure and then keeping it from bleeding off when you remove the air chuck is a challenge. In summary this is a very good unit possibly worthy of a 5 star review were it not for the difficulty adjusting air pressure, the need for installation documentation, and a necessary correction to the sales listing. The unit reviewed was made in China.

Think of an expansion tank as a shock absorber for your plumbing system. Every time your washing machine cuts off the flow of hot water by slamming a valve shut...; this device cushions the blow to all the pipes.

works like a charm on new tankless hot water heater

Passed the inspection in my new house. Doesn’t take up any room! Can you find it in the photo?

Worked perfectly as a very small expansion tank for the tankless DHW coil in my small residential boiler.