Surefire Heater Sentry - Emergency Battery Back Up for Pellet Stoves and Kerosene Heaters
For Heating Appliances - When Your Power Quits!

If you are a consumer wanting to purchase a Heater Sentry, please click here for retail sales.

During recent years several heating appliance manufacturers have added major operating refinements to their product designs. Consequently the electrical control systems in many pellet stoves and kerosene heaters have become more complicated and often microprocessor controlled. Latest models now require power sources that replicate the power waves generated by utility companies. The technical term for this type of power is "sine wave".

The Series 700 Surefire Heater Sentryprovides pure sine wave power suitable to operate any heating appliance within its ratings. When used with one or several batteries it will prolong the operation of appliances in the absence of electricity. Back up time depends on the number of batteries available and the electrical power level at which the appliance is operated. This power level is dictated by the appliances room temperature control settings. As a guideline each 100 A-hr battery will allow approximately 4 to 6 hours of operation when the appliance consumes an average of 400 Watts. Units consuming less power will go for proportionately longer periods of time.

Here is how it works ...

Surefire Heater Sentry interfaces between a kerosene heater and the 120 Volt AC electrical line.

When electricity is present Surefire Heater Sentry charges one or several batteries and monitors the power line. At the instant of power failure, Surefire Heater Sentry begins to convert the energy stored in the battery to sine wave AC power. This assures the uninterrupted operation of the kerosene heater at the start of a power outage.

When AC utility power is restored Surefire Heater Sentry reinstates AC utility power as the prime energy source to operate the heater. Simultaneously and automatically the Surefire Heater Sentry commences the recharging of the battery to speedily return it to full capacity in preparation for the next power failure.

At sites where utility power is not present, the user should determine if there is a sufficient reserve of the battery capacity to enable the kerosene heater to operate for the desired time period. Consult the Surefire Heater Sentry operating manual for data relating the size and number of batteries needed.

Figure 1 illustrates the interconnection between a kerosene heater, Surefire Heater Sentry and battery.

Technical Info
Technical Info
Electrical Specifications:
Model SF 707
Model SF 709
Normal model Operation
(Supplying Line Power)
Input Voltage Range
100-128 VAC
100-128 VAC
Input Current
6 A
9 A
Charging Current (max.)
12 A
12 A
Recharge Time (max.)
13 Hours
13 Hours
(FOR 90 A-HR. BATTERY Fully Discharged)
Back Up Mode Operation  
(Supplying Battery Power)  
Maximum Back Up Power  
600 Watts
1000 Watts
Maximum Input Current  
65 A
100 A
Switchover Time  
1/3 Sec
1/3 Sec
Factory Warranty
1 year
1 year

Each Surefire Heater Sentry consists of two modules. The Upper Module houses the Charger, Transfer Switch and Line Monitoring Circuitry. The Lower Module houses the Power Inverter and Remote Switch. All Surefire Heater Sentries are supplied fully assembled with detailed Instruction Manual.

Surefire Heater Sentry will operate all heaters consuming power levels within their respective power ratings.

For a product manual go to: SF 707 Manual or SF 709 Manual.

To select a Heater Sentry model:
Check your appliance's nameplate or operating manual to determine its input power demand. If not available check the input current specification. Multiply input current by 120 to calculate input power.

Select a Heater Sentry with a power rating exceeding your appliance's input power.