Should a Water heater have two check valves?

**wombat** · 08-21-2011, 11:22 AM

I that these kits to install new water heaters have two check vales in them. I understand why you would want a check valve on the cold water side but do I need one on the hot water side too (of course this is going in the opposite direction) ?

**Terry** · 08-21-2011, 11:47 AM

I'm not a big fan of checks on water heaters unless it's for a recirc line to make sure the flow is directed the correct way.

**jadnashua** · 08-21-2011, 12:07 PM

They can save a little money since the hot water can't migrate as far. This also means that the lines outside of the WH will cool off more, requiring a longer wait to get hot if it hasn't been run recently. It's not a huge difference, and insulating the lines helps to minimize that. There are two types that I've seen: one uses a plastic ball, the other uses a flap. In either case, they must be installed in the proper location, or it will block flow to and out of the WH rather than opening with the flow.

**wombat** · 08-21-2011, 12:16 PM

Originally Posted by wombat

I that these kits to install new water heaters have two check vales in them. I understand why you would want a check valve on the cold water side but do I need one on the hot water side too (of course this is going in the opposite direction) ?

Ooops I was confused! LOL The valves in these kits are dielectric nipples. That being said I was still intending on putting one on the cold water side only. Thank you for your answers

**Terry** · 08-21-2011, 12:26 PM

If it's only a dielectric nipple, then there's no check valve.

**jadnashua** · 08-21-2011, 01:25 PM

Well, that would give you a chance to see how effective the dielectric nipple is! Some people are fans of them, some aren't. Ideally, they help, in practice it's more of a tossup. If it was mine, and they came with the thing (they usually come in sets), I'd put them both in.