What does the high limit do - Bloomfield 8543 Coffee Maker

To test, jump the two leads on the high limit. However, this sounds most like a faulty gas valve. Most high limits are designed to cut off both the pilot and the main buner.

should be same as old one was.

What about the safety limits for over heating? You have tackled all obvious problems, I am only throwing this out there because while the high limit is jumped out, to get the open high limit is definitely strange. So i would be tracing my wiring backwards from the relay to see what else is in line with it. This is not a solution but only a suggestion before running out to purchase the main control board, as most places will not accept a board back if that is not the culprit. Good luck with this one it leaves me slightly puzzled??

I think you are on the right track with a faulty high limit switch. When i serviced these units we always replaced the operating thermostat and the high limit switch together they came in a kit. The operating thermostat in theory should never let it get hot enough to trip the high limit switch, which is really just a safety backup for the operating thermostat. Get the kit and replace both, and also make sure your exhaust vent going outside has good flow at the outside vent,a restricted vent system will cause similar issues.. Good Luck

Hopefully it has kicked out on high limit thermostat. It depends a lot ofn what type of control you have on your fryer. If they are all mechanical controls, the high limit may need to be reset. Open the front door of the fryer. There are two thermostat bulbs in the fryer. One goes to the thermostat with the temperature dial, the other to the high limit thermostat. Hopefully the high limit thermostat that you have will have a small red button sticking out. Push that button in and then relight the pilot as you would normally do. If your high limit thermostat does not have a red button it is an automatic reset high limit. When the fryer pot cools below 300 degrees it should reset itself. If you have electronic computer controls on your fryer you will have to reprogram your thermostat settings.

It might be the high limit, but it could also be the roll out switch or the flame sensor. Start by ohming out the simple switches the high limit the rollout if the are good use a piece of light grit sand paper or some emery and clean the flame sensor. This is a rod that sits in the flame of the burner telling the gas valve the burners are lite and it is okay to keep the valve open.

If the unit comes on and runs but then shuts down, that sounds like an indication of a high limit trip.

Most, if not all, furnaces have high limit switches that keep a constant check on the temp inside the furnace or air handler. On most systems, once this high limit switch has been made (got to hot), the limit switch breaks control voltage to the heating device (strips, gas, fuel, etc.etc..). The blower motor continues to run until the high limit has dropped in temp and reset itself.

On some models, the high limit is a manual reset, meaning you need to reset the switch yourself or shut the unit off and then back on to reset it.


Check all filters and replace as necessary. Check the coils and fan blades for dirt build-up and cleanliness. Check motor belt (if applicable). If all these fail to solve the problem, then your issue either lies within the blower motor itself not moving enough air for proper heat transfer. Or the high limit switch itself is failing.

Hi, you'll need a ohm tester (multi-tester) you will have to remove / disconnect wires from hi-limit, in normal room temperature, place tester lead on terminals where you remove wires, if you get a beep/continuity, hi-limit is o/k, if no beep/continuity, hi-limit faulty, for further test you can heat up hi-limit, (oven) and check with tester, hi-limit switch off when temperature gets to high, and switch on when temperature drops, so at room temperature hi-limit should be on, (hear beep on tester), if there's no beep/continuity at room temperature, high-limit is faulty. disconnect power before doing any repairs, good luck.

Hi, sometimes high-limit goes bad, but why, check to make sure you're not overloaded with produce, check to make sure freezer has good ventilation, if your days are hot, high limit will switch off, to pretect compressor, could be compressor getting faulty, you should empty freezer, clean and restart empty for an hour, if freezing o/k, put back produce, if when clean and empty, does same thing, maybe your compressor is faulty, called a mechanic, or replace high limit switch. good luck.