Pitco gas frialator reaches temperature dictated by thermostat then shuts down completely (pilot light goes out) and can not be relit

There are several possible causes of this problem, aside from a loose or damaged wire, which is uncommon. The cause in about 95% of the cases is a thermopile that has gone bad. The thermopile is the small cylinder that is attached to the pilot assembly where part of the pilot flame can contact it. It has a cable or wire going to the gas valve, high limit switch, or both. When hot enough, it produces and electrical current that keep the pilot on and allows the main gas valve to open. This is not hard to replace in most gas fryers and not too expensive. This often starts as an intermittent problem. The second possible cause is a defective high limit. The high limit is a small rectangular device with wires going to the gas valve and a tiny stainless tube that goes through the bottom of the kettle to a sensor bulb, like the thermostat has. These are usually self resetting, but may have a small red reset button. If present check the reset. If no reset, jump the two wires and see if the fryer will now light. If so, the high limit is defective, assuming the fryer is not over temperature. If defective, replace. Do not operate the fryer in this condition as there is no over temperature protection. The next cause is if the oil is too hot, in which case the high limit will shut off both the main burner and the pilot. The pilot cannot be relit until the fryer cools down and the high limit resets. If the oil is too hot, usually over 425F, replace the thermostat. If the high limit trips when the oil is in the normal operating range, replace the high limit. The final cause is a bad gas valve. This is not too common, but the gas valve is expensive and a bit difficult to replace. Check all of the other causes first.

Sometimes certain models turn off if you touch the thermostat before it lites...
We've seen this happen many times, so you would need to light the fryer first, wait until it's stable before turning your thermostat to desired temperature.

Hi there.
Make sure that the gas pressure being fed to the unit is sufficient or meets the required pressure on nameplate.
Try to check the hi limit it it has continuity across the terminals (with wires removed during checking) when it shut down, if the hi limit has continuity across the terminals- it is good; if it has none- it is tripped so check the oil temperature, hi limit trips at temperature around 450F. Verify also the temperature setting and the thermostat calibration.
If the unit has thermopile, it should be free of soot or any form of dirt. All wiring connection must be tight.
For calibration procedure, wiring diagram and other troubleshooting references, you can visit http://www.pitco.com
Regards.

Hi there!

Gas valve and thermostat are two different parts. If you are having problem with the oil temperature, your thermostat probably is not doing its function well, that is, to regulate the oil temperature set on its dial, and needed to be replaced.

Regards.

The thermostat mechanical contacts may be bad, try replacing the thermostat.

Check if your pilot flame sufficiently heats thermopile during operation and make sure also that it is free of soot or any form of dirt, thermopile generates small amount of electricity to energize pilot and main valve of the gas valve for pilot and main burner operation. This electricity passes through hi limit mechanical contacts. Hi limit on fryers act as safety device which will shut down pilot and burner flame when oil temperature reaches 450F.
If your fryer is set at 350F and over shoots up to 450F (which will trip hi limit and shut down pilot and burner flame), the thermostat is not good, but, if hi limit trips on temperature much lower than 450F, hi limit is bad.

Check the hi limit sensing bulb, it should not touch the fire tube, when it does, it will sense high temperature which will trip its mechanical contacts and will shut pilot and burner flames.
Make also sure that the thermopile is free of soot or any form of dirt and is properly heated by the pilot flame.

Try to spray wd40 on knob.
If spraying wd40 doesn't work, you have to replace the gas valve.

It shuts down because it is tripping the high limit. Apply a soap solution to the lines going from the gas valve to the thermostat. If bubbles appear there is a leak and needs to be corrected. If no bubbles appear then the thermostat is probably your problem.

Assuming that the pilot is lit, when you turn the thermostat from off to the operating temperature, you should hear a click at some point. If you do not, the thermostat is defective. You can also double check this by detaching one of the two wires going to the thermostat and measuring for continuity between the two terminals. At off it should show no continuity. At 200F or above it should show continuity. This is the most common problem.

If the pilot will not stay lit or if it goes out when you increase the thermostat setting, it is usually a defective or weak thermopile (or thermocouple), or a defective gas valve. If replacing the gas valve, I recommend replacing the thermocouple or thermopile at the same time.

Restate your problem if the pilot won't stay lit or if it goes out when you turn the thermostat up.