Gas Furnaces

Furnace service.

Lonestar Comfort Services is the leading HVAC company in Castroville, TX, for your furnace service needs. We service and repair all makes and models. If you need furnace service, we are the company to call. Our skilled technicians are qualified to solve just about any repair or installation that you throw at us.

How Much Money Can a New Furnace Save You?

Our AFUE energy savings calculator can help determine how much you could save on your utility bills. Simply enter your current unit's AFUE value and compare it to a newer, more efficient system. You can even customize it to better match your home's system for a more accurate calculation.

AFUE Energy Savings Calculator

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This calculator does not guarantee actual costs or savings and is only to be used for educational purposes.

Customize to Your Home

Adjust these settings for a more accurate calculation:




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Historical Comparison

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** Data from U.S. Energy Information Administration
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Furnace Repair

Don’t get left in the cold! Is your furnace acting up, blowing cold air, or making too much noise? Our experienced team of professionals is here to keep your home warm and cozy. We repair all makes and models, and we will never try to sell you a service that you don’t need. Our technicians are honest and hard working, and we’re always transparent and fair about the work we do.

Furnace Replacement

Sometimes a repair is not sufficient to fix your furnace. Sometimes a new furnace is the most cost-effective and energy-efficient way to go. We will always be honest with you about a possible furnace replacement. We value our time and your money––we don’t want to perform repairs or service on an appliance that is in need of replacement.

If you do need a furnace replacement, we know how overwhelming it can be. Here are some of the frequently asked questions about furnaces that we get from some of our Castroville, TX residents:

What Are The Different Types Of Furnaces?

Single Stage: A single-stage furnace has only one stage of operation. It can either be turned on or turned off.

Two Stage: A two-stage furnace has two settings––full and half speed. This is a more efficient way to heat and provides for better comfort, because it can move the air at a slower pace.

Variable Stage or Modulating: A variable-stage or modulating furnace modulates the speed and heat output based on the temperature outside and the desired comfort level. This furnace only works as much as you need it, making this type the most energy-efficient type of furnace.

What Is AFUE?

AFUE, or Annualized Fuel Utilization Efficiency, is a measure of furnace-heating efficiency. The higher the AFUE, the more efficient the furnace.

What Size Furnace Do I Need?

We can calculate the correct size furnace for your home. The number of BTUs, or British Thermal Units, needed to heat your home is dependent on a number of variables. Contrary to what you might think, a bigger furnace may not necessarily mean more heating power for your home. Call us at Lonestar Comfort Services, and we can set up an appointment to calculate the furnace size you might need.

Gas Furnace Maintenance in Devine, TX 78016-4504

“The original installation was amazing.. the follow up service was well amazing. It’s obvious the owner Keith truly takes pride in his employees and customers alike. Thanks for the excellent service keep it up!!!!!!”
- Donald B.

Gas Furnace Maintenance in Castroville, TX 78009

“Professional knowledgeable technician did maintenance on furnaces and explained results in clear way.”

- Dan M.

Gas Furnace Maintenance in Hondo, TX 78861

“Ryan Delgado did an overall seasonal check on the fall tune-up. Very knowledgeable and kind. Thank you for your services LoneStar.”

- Karen B.

Gas Furnace Replacement in Castroville, TX 78056

“I called Lonestar for what I thought was a thermostat problem. Brandon Jonas, the service manager, arrived on time and performed a thorough inspection. He determined that there was a wiring issue and advised me of other issues that needed attention. He repaired the wiring and offered a maintenance service plan at a reasonable cost with sizeable discounts for any additional work that might be necessary (some that I was aware of). On his return visit, he provided estimates for repairs and/or furnace replacement. Since the unit was 20 years old, I opted for replacement. He fully explained the scope of work and cost and benefits. Richard and Rene, the installers/technicians were very professional, courteous. In addition to the furnace, they installed two return air grills, additional ductwork and equipment for energy savings. A follow up visit to inspect the work was done and now I have a much quieter system with more even cooling (my kitchen is not as hot when I cook…Thank You!) I would definitely recommend Lonestar for any HVAC maintenance and repair. The no interest monthly billing plan makes is much easier on my budget.”

- Barbara C.

Need Furnace Service?

Contact the experts at Lonestar Comfort Services.

Call us at 830-538-9450!