Rails 3.2, Tire gem and Elasticsearch still Request Timeout

I took over after another programmer shop build with Rails 3.2, Turbolinks, (Re)Tire gem and Elasticsearch (0.20.6). The shop has 26k products, 4 languages.

After a few hours I get error RestClient::RequestTimeout: Request Timeout and shop returns 503. After restarting Elasticsearch, it works fine for a couple hours and again returns 503.

Any ideas how fix it?