Description
Sunstar SIR Eclipse U-Tube Heater | SIR25-15-N7
The Sunstar SIR25-15-N7 is a 25,000 BTU/hr natural gas Eclipse infrared heater with a compact 15-foot U-tube emitter that hangs in a little over nine feet of space. Every tube is heat-treated aluminized (Tough Guy) steel, and it is approved to mount as low as 8 feet, which makes it a natural fit for two- and three-car garages, small shops, wash bays and covered patios.
Like the larger SIS heaters, the Eclipse is a vacuum system that pulls combustion through the tube, and its U-tube layout keeps heat output even from end to end instead of running hottest at the burner. Ignition is direct spark with 100% gas shut-off and a 30-second pre-purge.
This is a two-stage model: it fires at 25,000 BTU/hr on high and drops to a reduced input on low, so it can hold temperature on milder days with less gas and fewer on/off cycles. Control it with a two-stage 24V thermostat or a three-position High/Low/Off switch.
For planning, mount it at least 8 feet above the floor when level or 8 feet when tilted 45 degrees, and keep 41 inches clear below it and 8 inches to the sides. It can be vented on its own, common vented with other heaters, or run indirect vented with building exhaust, and it can draw outside combustion air through its fresh air collar in dusty or humid buildings. Installation must be done by a licensed contractor to the manufacturer’s instructions and local codes.
Key Features
- 25,000 BTU/hr natural gas input, reduced on low fire
- Compact 15' Tough Guy U-tube, mounts as low as 8'
- Vacuum design pulls combustion through the tube for added safety
- Direct spark ignition with 100% gas shut-off
Frequently Asked Questions
How high should the SIR25-15-N7 be mounted?
Sunstar lists a minimum of 8 feet above the floor with the heater level and 8 feet at a 45-degree tilt. Mount it as high as the space allows for even coverage; going below the minimum can make the area right underneath uncomfortably hot.
What clearance does it need from combustibles?
Keep at least 41 inches below the heater and 8 inches to the sides clear of anything that can burn, including stacked materials and vehicles parked underneath. The full clearance chart, including ceiling and end distances, is in the installation manual.
Can I convert it to propane?
Conversion requires the Sunstar factory kit for this exact model, installed by a qualified technician, so the simplest route is to order the heater for the gas you have.
How do I control the two stages?
Use a two-stage 24V thermostat to switch between low and high fire automatically, or a three-position High/Low/Off switch for manual control. Several heaters can share one control with a two-stage relay kit at each heater.
