Heller Heating Element

Typical problems with our heller 1707 EXL would be blower issues. We have almost replaced every blower on the top sense purchase. Fortunately Heller is very good about honoring there warranty on the blowers which is quite long, Might be lifetime not sure.

If it is 1 of the last 3 zones check the blower fan for blockage or buildup of flux residue. Also check the blower for bearing run out or play(our cold zone still ran but had 1/4 inch of side to side run out in the bearing when we replaced it last annual inspection/cleaning.

The blower to be weary of are the Black panted metal can style motor, they have a sticker on the top covering the shaft, They also have a large steel can run cap on the side. Silicon Power brand IIRC.

Our newer blowers we have been getting are gray pot metal with a magnetic sheet steel stack in the middle for the windings (looks like a washing machine motor but narrow), the run cap is a modern polyester epoxy potted cap, and is a lot smaller. These we have yet to have a failure on. Might be AO smith IIRC.

Run the oven with the top about 1 inch up, measure the temps with a stiff thermocouple and a fluke, Run the zones at say 1/2 normal temp but enough to make the instability show up. SET THE BELT SPEED to 1 inch, this will stop the belt and prevent thermocouple entanglement.

With the oven lock out tag out, go to the thermocouple board and connect the zones thermocouples to a fluke rated for type K thermocouples, You will want to do this with the oven hot after a cool down cycle and have someone else blow compressed air (NOT CANNED AIR, CANNED AIR = Propane variant = Explosive) in to the zone. We have yet to have a heating element or thermocouple go bad on our 1707, Our old 1500 had a heating element go bad.

This will let you check the thermocouples stability (before you blow air), and its temperature response (with air flow). Perhaps compare to a adjacent zone.

You can verify SSR operation using a standard fluke, and there software, the software will tell you the duty cycle, and the fluke should be able to make some sense of the lower duty cycle. A cheep multimeter may work better. New ovens have a green LED that is on when the element is, and will flicker rapidly during normal operation(duty cycle).

Hope this helps

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I'm guessing you don't have the oven's manual, there's a great section in the Heller manuals about trouble-shooting the zones, that gives that resistance measurement.

I no longer have a Heller, and can't remember what that measurement is, however. But, if you give Heller a call, they'll point you in the right direction. They're tech support is excellent, and they will usually help with even third party machines.

Cheers, ..rob

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