Gaggia threaded Coffee Thermostat for all semiautomatic espresso machines. Temperature contol limit 107Cl. Used in most Gaggia old or new semi automatic home models and other espresso applications. For exploded diagram and parts list, use linkhttp://www.partsguru.com/user/Parts%20dagram%20ER0182_Rev01.pdf .
Have you descaled your espresso machine lately? It is the single most important maintenance for all espresso machines. Cleancaf, Cafiza, Joe Glow, Brew Rite, Pulycaff are products sold as descaler but they contain only Baking Soda which is totally ineffective. Use Best descaler #DSC-6,
available on this Internet store.