Do you have any Relays with gold-plated contacts?
Even if Relays are not used and just stored, the contacts may deteriorate. Contacts are less susceptible to the environment if gold plated.
Consider different contact mechanisms when using microloads.
New Latching Levers for Circuit Checking Added to Our Best-selling MY General-purpose Relays
Power-switching Compact General-purpose Relays
Compact, Slim-profile SSRs with Heat Sinks. Solid State Contactors for Three-phase Heaters Reduced Installation Work with DIN Track Mounting.