Will try to give you all the info you need to help me with description of my problem.

I have a third "recirculation" copper line plumbed for "instant hot water" to all faucets/showers etc.
The system works on the principal of Thermosiphoning where hot water rises and cold falls.
The system works GREAT...actually tooo good because it causes the 80 gallon hot water to cycle like crazy (as in every 10-15 minutes) primarily due to the fact that cold water is constantly being recirculated back into the HWH causing it to turn on. I understand that nothing is free and it costs something to have the hot water ALWAYS there when you turn on the faucet or shower BUT I feel I can save ALOT on the life of the HWH AND save alot of propane by only having the circulation system turned on during the morning "get ready for school/work" hours & maybe a few hours in the evening. Don't need the instant hot water during the day when no one is home. Currently there is a manual ball valve in the 1/2" recirc line that goes into side (near the bottom) of the hot water heater. I would like to replace that manual ball valve with a selenoid actuated normally closed ball valve that I can have plugged into a simple appliance timer to control it. I also Know that I COULD install a Grundfos recirc pump but my system works too well the way it is; I just need to throttle it back a bit.

The water coming back to the HWH via the recirc line is warm(80-90deg) at best so NO need to use a valve for steam or even boiling water. I think(?) I think I know what I need but alternative ideas welcome.
I just can not seem to find what I need without breaking the bank. Have had several supply houses try to sell me steam valves for $700. I would appreciate a tip as to what brand or where I can find what I need at a reasonable price.

Just need a simple 2 way normally closed 110 volt ball valve with electrical terminals that I can connect a 12/2@ground pigtail to then plug it into the $10 digital timer with battery backup. that's it.
Seems like a simple DIY project but I cant' find what I need. many thanks in advance!!!!!
tom