I would suggest have a scroll at Aliexpress Few years ago i bought a (CNZNTIL 3 way) DC 12V 3W solenoid connected to a 12 volt Cn101A timer Together less than $ 20, free shipment and worked for years without issues.. Always a good idea to buy 2 of each to have a spare in case. Than you don't have too run around like chicken without a head to find a replacement before all comes crashing down.. And still earned their monye back before they are in operation.
than you need to add a dc 12V 5W PSU, if you don't happen to have one.
But as said, i used mine for at least 3 years 24/7, no issues.. Than i stopped using CO² for other reasons. So they might still work today..