Archive for December 9th, 2014

Taylor 1478 Kitchen Thermometer: Probe Wire Failure

We’ve been doing a lot of roasting and bought a not-dirt-cheap Taylor 1478 digital kitchen thermometer with a long probe wire to monitor the meat temperature. As soon as I unpacked it, I knew this would eventually happen:

Kitchen thermometer - nicked probe wire

Kitchen thermometer – nicked probe wire

The cable lasted just long enough to ensure the thermometer warranty expired; it’s a deliberate design flaw if I’ve ever seen one.

The thermistor inside the probe seems to be 100 kΩ at ordinary temperatures, although I’d be completely unsurprised to find that Taylor uses a slightly nonstandard resistance. Because nonstandard, of course.

Anyhow, replacement probes (*) are readily available from the usual Amazon suppliers, feature stainless steel braid sheathing and cost about as much as a whole new thermometer (albeit those still have cheap plastic insulation). With a replacement on order, I hauled the failed probe to the shop for an autopsy and possible resurrection…

Although I hoped that hammering out the crimp would release the thermistor, it was not to be. In retrospect, pulling on the probe wire probably killed it, but I didn’t know that at the time.

A spring intended to stabilize tubing while bending worked just fine to un-bend the probe:

Kitchen thermometer - unbending

Kitchen thermometer – unbending

But, alas, the thermistor still didn’t emerge from the more-or-less straightened probe.

Some deft work with a Dremel cutoff wheel sliced enough off the stainless steel tube that I could splice the wires:

Kitchen thermometer - probe cutting

Kitchen thermometer – probe cutting

More cutoff wheel work smoothed the edges of that raw cut end, although the result wasn’t anything to show off.

The spliced and insulated probe definitely don’t win any awards, either:

Kitchen thermometer - probe rebuild

Kitchen thermometer – probe rebuild

I doubt that the heatshrink tubing or silicone wrap underneath it would be suitable for roasts in the kitchen, but that’s moot: the probe remained intermittent.

If the new probe is also intermittent, then I’ll suspect the crappy 2.5 mm jack in the side of the thermometer…

(*) It’s not clear that a replacement probe for a 1470N thermometer will work with a 1478 thermometer. I’m gambling that Taylor wouldn’t be so stupid annoying deliberately obtuse as to use different probe thermistors, but that’s surely a bad bet. There’s no reason to believe Taylor actually makes any of this stuff, which means different models may come from entirely different designers / factories with entirely different supply chains.