Arrived on site to check Groen steamer. Customer said unit would intermittently shut down and would have to restart unit. Brought steamer into operation but, could not duplicate customers problem with unit. Did find operating pressure pushing hi limit pressure of 15psi at 14.5psi. Also found air vent not closing and seating properly, allowing steam to drain allows flowing. Removed water level probes and found heavily corroded, cleaned as best as possible. Operating pressure is varying between 10 and 14.5 psi. Tried adjusting operating pressure switch with no response, Pressure not changing, will obtain new probes, pressure switch and air vent, return and replace. steamer in service