Welch Allyn SureTemp 678 679 Repair

The Welch Allyn SureTemp 678 and 679 are professional digital thermometers designed for use in clinical and healthcare settings globally. They are intended for use by medical professionals such as nurses and doctors, rather than for personal, at-home use. These devices measure oral, axillary (underarm), and rectal temperatures and are built for frequent, reliable use by medical staff. The devices are typically mounted on a wall or attached to a rolling stand, making them easy to access during patient care.

These thermometers are part of Welch Allyn's larger line of diagnostic equipment used in healthcare settings and are part of the SureTemp family, which includes newer models with updated digital interfaces and features. One of their main features is the use of disposable probe covers, which help prevent cross-contamination between patients. They operate using predictive technology, which allows them to deliver readings in just a few seconds, along with a monitor mode for continuous temperature tracking when needed. According to manufacturer specifications, the devices are designed for accuracy and efficiency, with a temperature range of approximately 84.0-108.0℉ and an accuracy of about ±0.2℉.

The SureTemp 678 and 679 have been discontinued and are considered obsolete by the manufacturer, with no official repair or service support available.

A Class II recall was issued in September 2025 for certain oral/axillary probes used with SureTemp devices, including models 678 and 679. The recall was related to probe configuration settings, where some devices could produce inaccurate readings that were lower than the patient's actual temperature. Because these devices are used in healthcare settings, accurate readings are critical.

Like many frequently used medical devices, common points of failure include the probe, which can wear down over time, and the battery or electrical components, which may develop corrosion or connection issues. These types of problems are often the result of repeated daily use in clinical environments.

The Welch Allyn SureTemp 678 and 679 are handheld digital thermometers typically mounted in a wall unit or placed on a mobile stand. The device consists of a rectangular base unit with a coiled cord attached to a probe. The probe is stored in a holder on the front of the unit when not in use and is covered with disposable probe covers during operation. The front of the device includes a small digital display screen and several buttons for powering the device and selecting temperature modes.

The units are generally off-white or light gray, with a simple design. The front panel includes a colored section, usually blue or green, where the Welch Allyn logo and mode selection buttons are located. The probe handle is shaped for easy grip and is often color-coded by use (blue for oral/axillary and red for rectal). The unit is relatively compact and designed to fit comfortably in the hand during use.

The model number is typically located on a label on the back or underside of the base unit. The overall layout, probe system, and front panel design can help distinguish the SureTemp 678 and 679 from similar thermometer models.

• Display: Digital LCD
• Units: Fahrenheit and Celsius
• Power Source: 3 AA Alkaline batteries

• Measurement Types: Oral, axillary, and rectal
• Temperature Technology: Thermistor-based
• Response Time: ~4 seconds (oral), ~10 seconds (axillary), ~15 seconds (rectal)
• Temperature Range: 84.0°F – 108.0°F (28.9°C – 42.2°C)
• Accuracy: ±0.2°F (±0.1°C)
• Operating Modes: Normal Mode (standard readings) and Monitor Mode (continuous measurement)

• Dimensions: ~2.25 × 3 × 7 in (5.72 × 7.62 × 17.78 cm)
• Weight: ~10.5 oz (300 g)
• Mounting: Wall mount or mobile stand

• Probe Type: Detachable probe with coiled cord (oral/axillary and optional rectal)
• Probe Covers: Disposable, single-use

SureTemp Probes 2005 FDA Recall

SureTemp 678 Discontinued

SureTemp 679 Discontinued

FDA Recall Notice

678 & 679 SureTemp Technical Manual

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