Preventing emptying of hot water tank

[Chucky_ott]

I'm building an addition to a three-season cottage. The addition will hold the hot water tank and the cold water intake (at bottom of tank) will sit higher than some of the fixtures in structures adjacent to the new addition. If we were to lose water pressure for some reason (e.g. leak in pipe, call for water during a power outage, etc), I think there is a potential for the hot water tank to drain. If this happens, the heating element will likely burn out.

To prevent the tank from draining, I'm thinking of adding a check valve on the cold water line close to the water heater. Although I had not planned on installing a thermal expansion tank (the pump's expansion tank would have taken care of that), the addition of the check valve will likely require the thermal expansion tank. So now I would have a check valve, followed by the thermal expansion expansion tank, before the water heater.

Another option was to have the intake pipe loop up before the tank in order to create a "trap" on the supply line. But I'm afraid that this won't be as effective since water may siphon out of the tank anyways.

Are my worries of the tank draining justified ? Is a check valve a good solution ? If so, what type of valve is better? Swing type or spring type ?

TIA

 

[GReynolds929]

They make vacuum breakers for this very situation.

 

[Sponsor]

 

[Chucky_ott]

Fantastic. Did some googling and found the Watts LFN-36 vacuum breaker available locally. Thanks!