Dan Listermann wrote:
"jeff_wisnia" wrote in message
...

Can you try telling what's going on by feeling the cold water piping on
both sides of the check valve while someone else opens a cold faucet?


I did that and it gets hot right away. Are spring loaded check valves
common in house plumbing?



I'd say that "Warm Hand Luke" test pretty much proves that your original
suspicions about the check valve not closing are correct.

The present valve may have worked when new, but might have gotten
grotted up over time and won't close now, which could have nothing to do
with its orientation.

I've always had good luck with Watts products.

Here's a data sheet on one of their series of spring loaded check valves:

http://www.watts.com/pdf/ES-600.pdf

One the right size should work slicker than snot to solve your problem.

After putting in a new check valve it wouldn't hurt to check the
expansion tank to make sure it's still working as it should. With the
present check valve "leaking" you wouldn't have noticed if the expansion
tank got "full" or has a ruptured diaphragm.

Happy Landings,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.