How should level control be specified for commercial heating elements?

Level control must keep the heated section submerged at all times. Before ordering, specify normal, minimum and refill trip levels to the supplier, and choose the sensing position based on vessel shape, inlet and outlet flow rates and surface movement during heating to avoid false trips. On low level, the heating circuit should de-energise or cut power within seconds, with the response time matched to the sensor type, mounting height and control logic. With automatic refill, verify protection under refill failure, sensor fault and drain conditions so a single signal fault cannot cause dry firing. Record the agreed levels, response times and protection logic in the technical agreement for acceptance and commissioning, and confirm the actual low-level trip and reset levels during commissioning.