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3/ Check connections to sensor.
4/ Check calibration – using independent thermometer,
follow instructions in section 6.4.
Unit will not heat up at all
1/ Check amperage – amperage should be virtually at
maximum rated (data plate) amperage.
2/ Do all controller functions work?
3/ Is the Safety Thermostat set high enough? – for
diagnostics, should be fully clockwise with the OTP light
never on.
5/ Has the fuse/circuit breaker blown?
6/ Has timer turned unit off?
7/ For “S” suffix models, verify that the Reset button has
been pushed in.
Indicated chamber temperature
unstable
1/ ±0.1 may be normal.
2/ For G suffix models: may vary ±2.0 degrees.
3/ For F suffix models: is fan working? –verify movement
of air in chamber.
4/ Is ambient room temperature radically changing – either
door opening or room airflow from heaters or air
conditioning ? – stabilize ambient conditions.
5/ This may happen if exhaust stack is 100% open or if
power exhaust is cycling – adjust stack to at least ¼
closed.
6/ Sensor miss-located, damaged or wires may be
damaged - check mounts for control and OTP sensors,
then trace wires or tubing between sensors and controls.
7/ Calibration sensitivity – call Customer Service.
8/ High limit set too low – be sure that Safety Thermostat
is set more than 5 degrees over Main Controller set point;
check if OTP pilot is on continuously; turn controller knob
completely clockwise to see if problem solved then follow
instructions in section 6.5 for correct setting.
9/ Electrical noise – remove nearby sources of RFI
including motors, arcing relays or radio transmitters
10/ Bad connection on temperature sensor or faulty sensor
– check connectors for continuity and mechanical
soundness while watching display for erratic behavior;
check sensor and wiring for mechanical damage.
11/ Bad connections or faulty solid state relay – check
connectors for mechanical soundness and look for
corrosion around terminals or signs of arcing or other
visible deterioration.
12/ If set point is below 60 degrees, temperature can be
unstable. See unit specifications for individual ranges.
Will not maintain set point
1/ Assure that set point is at least 5 degrees over ambient.
2/ See if ambient is fluctuating; check for adjacent open
doors or HVAC duct openings – stabilize ambient
