I am installing a thermal expansion tank and the maker (Watts) recommends installing a service check valve between the tank and the pipe.

While I understand the convenience factor of the SCV, my concern is that I would be introducing another potential point of failure into the system by adding a service check valve. Is it advisable to do this?

1 Answer 1


Yes, it is good practice to fit an isolation valve.

This makes replacement of the expansion tank easy without draining the whole system.

This is also a practice followed for many components in a water system, as these valves are cheap & reliable, so putting them either side of a pump can save a lot of hassle when trying to bleed a system.

  • Hi, Mike. Sounds like a good answer, but would you mind adding a bit of context, or just a few more sentences of support? We don't usually like sentence-fragment answers. (Thanks.) Mar 13, 2019 at 15:15

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