The OnWatch Model 51 acts as a 24/7 service technician, diagnosing system problems as it monitors system operation.

One of the most dreaded words in an HVAC contractor's vocabulary is "callback." The very mention of the word sends chills down the spines of business owners who know that callbacks affect profitability and reputation. The word also gives service techs the shudders because they know their reputation and record takes a hit every time their work requires a second visit.

Although some callbacks are unavoidable because of parts failures, others can be avoided by a proper diagnosis of the original problem and corrective action taken.

"Many people in the business don't recognize how much callbacks cost," said John Bunting, president of OnWatch Electronics Inc., maker of the OnWatch Model 51, a diagnostic tool for oil and gas burners.

"And the problem is that most businesses don't charge for callbacks because they are the experts and they are supposed to get it right the first time."

Bunting said that with callbacks costing as much as $75 to $100, the problem is one that contractors cannot ignore.

Another reason that callbacks are costly is that a contractor's reputation is at stake. "After a tech makes more than one return to a home, the customer starts to question the quality of the contractor's work," he said. "It is one thing to have a callback, it is quite another to lose a customer."

The OnWatch Model 51 comes in a kit of tools used to attach to oil-fired heating equipment.


According to company literature, the OnWatch has the following features:

  • Polyethylene carrying case with oil-resistant foam

  • Complete manual with User's Guide and Diagnosis Manual

  • Stack temperature sensor

  • Gas inlet and outlet pressure sensors

  • Model 52 interface (for electrical connections to oil burners)

  • Model 53 interface (for electrical connections to gas burners)

  • Oil burner pressure sensor

  • Oil vacuum sensor (option)

    Alan Mercurio, oil service technician and founder of, said he wouldn't go on any job without the OnWatch.

    "I don't just sell the OnWatch [at his Website] I use it myself anytime I have a nuisance call that I just can't babysit," he said. "The OnWatch can stay at the call 24/7 until the system fault takes place. And if that's not good enough, it also displays a message for the customer that the fault has been detected and they should call the service company. And yes, it even displays the service company's phone number. How cool is that?"

    The OnWatch Model 51, a diagnostic tool for oil and gas burners, can save oil heat contractors hundreds of dollars on costly callbacks.

    Some of the most common problems the OnWatch can detect in oil burners includes motors with dead spots, motors with locked rotors, intermittent low line voltage, chattering thermostats or boiler controls, clogged fuel lines, any increase or decrease in pump pressure, faulty primary controllers, delayed ignition, direct vent contamination.

    Being able to find these problems are a must for preventing callbacks, and can lift a large burden off the shoulders of a service tech.

    "Put yourself in the shoes of the tech," said Bunting. "He has to be a diplomat and not just a tech. There are more pressures on him to solve the problem. The OnWatch gathers data 24 hours a day until the burner locks out.

    "We dramatically increase the odds of the service tech finding the problem."

    Mercurio agreed, especially when time and money is important to both the tech and the customer. "Once I arrive, all I need to do is read the history of what took place right up to the time of the failure and make the necessary corrections," he said. "I can't even begin to tell how much money has been saved with the use of this instrument, but I can say that it pays for itself within the first few calls. The rest is money saved for the contractor's bottom line."

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    Publication date: 11/27/2006