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1808 PD: Engine block heater timers for tractors save money

Published on 09 December 2008

Tractors and other farm equipment can be a challenge to start in cold weather, so many farmers install block heaters to preheat their engines.

Most times, these heaters are left plugged in whenever the tractor is not in use or plugged in the evening before the equipment will be used.



“However, a typical block heater usually needs only one to two hours to warm an engine for starting,” according to Michael Kawleski, manager of the Wisconsin Public Service Agriculture Department. “Using a timer on a block heater can save up to 85 percent on its energy costs.”

A simple 24-hour clock timer can automatically turn the heater on so it’s ready when needed. The energy savings will typically pay for the timer in one to three months.

A 1,000-watt engine heater that runs 10 hours per day (e.g., overnight) from late November through mid-March will use about $100 in electricity. Activating the engine block heater with a timer two hours before it’s normally used saves about $80 in electricity per year (see Table 1*).

For 120-volt block heaters of 1,800 watts or less, plug-in timers are available that cost about $20. For block heaters over 1,800 watts, or heaters that operate on 240 volts, timers will cost $40 to $60.

Timers are available at most hardware stores and building centers. Timers should be outdoor- or weatherproof-rated and installed on properly grounded electrical circuits, stresses Kawleski.


Online calculator computes savings from heater timers
A calculator on the Wisconsin Public Service website can help farmers estimate what they’d save by using a block heater timer. Just go to and click “Energy saving tools & ideas”, then “Savings calculators”. PD

*Table ommited but is available upon request to

—Excerpts from Wisconsin Public Service Corporation news release