When the crew is walking into the retirement home, you can see their ambulance is parked outside. On the side, near the back, you can see the number 14, implying that they were driving ambulance 14 (their normal one) despite being assigned to ambulance 8 after the robbery.
After the ambulance was robbed the crew is temporarily reassigned to "Rig 8". After complaining about the new rig, they are dispatched to a nursing home. Hank radios "Ambulance 8.. the raggedy ambulance.. responding". In the next scene, while walking into the nursing home, 14 is clearly visible on the ambulance.