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Furnace Replacement
When a Repair Stops Being the Smart Money
A furnace in Central Texas does not wear out from run hours the way one in Minnesota does. What kills it is age, heat and neglect: twenty summers in a 130-degree attic, a heat exchanger that has expanded and contracted through thousands of cycles, and a blower that has been running the air conditioner nine months a year the whole time. When that furnace finally needs a heat exchanger, a control board and a blower motor in the same season, you are paying new-furnace money to keep an old one alive.
We will tell you when that line has been crossed, and we will tell you when it has not. A furnace with a sound heat exchanger and one failed part is usually a repair, and we are happy to do it. When replacement is the right call, we size the new unit from your house, not from the label on the old one, because a furnace that is too big short-cycles and never gets the air evenly warm. We also look at the whole system: the AC coil that sits on top of the furnace, the ductwork it feeds and, in an all-electric home or one where the gas furnace is the only gas appliance, whether a heat pump would serve you better for less.
Every install over $3,000 is quality-reviewed by a manager, the quote is honored for 72 hours, and financing through Service Finance Company is available with no interest and no payments for six months, subject to credit approval.
Looking for your local team? See furnace installation in Austin or furnace installation in San Antonio.
- Sized from a load calculation Square footage, insulation, windows and ductwork decide the size. The old sticker does not.
- Repair or replace, honestly Both numbers side by side, in writing, with no pressure to pick the bigger one.
- Reviewed before we call it done HVAC installs over $3,000 get a manager’s quality review under the Home Comfort Guarantee.
When to Replace
Signs Your Furnace Is Near the End
None of these alone means replace. Two or three together usually do.
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A cracked heat exchanger
The one that decides it. A cracked exchanger can push combustion gases into your air. It is rarely worth replacing on an old furnace, and the unit should stay off until it is.
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A second major repair in two years
A blower motor last winter and a control board this winter is a pattern. The next part is coming, and repair money starts to look like a down payment.
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Rooms that never warm up evenly
Often an oversized or worn single-stage furnace that blasts, shuts off and leaves the far rooms cold. Sometimes it is the ducts, and we will tell you which.
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Bills climbing with the same habits
A furnace losing efficiency runs longer to hit the same setpoint. In an all-electric home, this is often heat strips running when a heat pump should be.
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Your AC is being replaced anyway
The evaporator coil sits on the furnace and shares its blower. Replacing both at once avoids a mismatch and a second install charge later.
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A bang at every ignition
Delayed ignition from dirty or misaligned burners stresses the heat exchanger every time it fires. On an older unit, that damage adds up fast.
What We Install
Furnace and Heating System Replacement
The furnace is one piece of a system. We replace it so the rest of the system works with it, not around it.
- Gas furnace replacement Single-stage, two-stage and variable-speed models, with the venting, gas connection and condensate drain done to code.
- Electric furnaces and heat-strip air handlers For homes without gas: new air handlers with correctly sized electric heat and a breaker that matches.
- Furnace-to-heat-pump conversions When the numbers favor it, one outdoor unit that heats and cools, with a furnace or strips kept as backup for the rare hard freeze.
- Matched evaporator coils The coil on top of the furnace has to match the outdoor unit. We replace it when it does not, so the AC side is not compromised.
- Duct and plenum corrections A new furnace on a crushed return or leaking supply plenum will never deliver its rating. We fix the connections while we are there.
- Thermostat and controls A two-stage or variable-speed furnace needs a thermostat that can drive it. We wire it right and set it up before we leave.
How It Works
From Estimate to a Warm House
Measured, quoted in writing and reviewed before we call it finished.
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We look at the whole house
The existing furnace and coil, the ductwork, the attic, the gas line and venting, and how the rooms actually heat. Then a load calculation.
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You get options in writing
Usually two or three, from a straight replacement to a higher-efficiency or heat-pump setup, with the price of each. Honored for 72 hours.
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Installation day
Old unit out, new furnace set and connected, venting and drain run, coil matched, controls wired. Most furnace swaps finish in a day.
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Start-up and quality review
We fire it, verify gas pressure, temperature rise and airflow, and walk you through the thermostat. Installs over $3,000 get a manager’s review.
Current Specials
Save on the work your home needs most.
Ready for a Furnace Quote?
A written estimate with options, no pressure and no obligation.
What Our Customers Say
Don't just take our word for it — hear from our satisfied customers
★★★★★
Our 18 year old HVAC system finally gave out this past week, so we reached out to Radiant to see what could be done. They sent a tech out named Bryan the same day, and he did a great job looking over the entire HVAC system. He was friendly and helpful in explaining everything that he saw, and our options moving forward. We decided to replace the entire system, so we met with Jacob (same day thankfully) to find the best HVAC system for our needs. Jacob was friendly, professional, and did a great job explaining the different options on offer. Radiant was able to set-up next day install, which was much appreciated, because the temps were still going to be cold in the coming days.
The install team consisted of Carlos and Pablo, who were very courteous and professional, and were kind enough to answer any questions I had regarding the install. They did a great job installing our new HVAC system, and were tidy which is always appreciated! Before they left, they explained everything that had been done, and showed me photos of the work.
Our entire experience from start to finish was great. I appreciate that they send photos of who is coming to your home too. Friendly, kind, professional team members, and good work all the way around. Thanks Radiant!
The install team consisted of Carlos and Pablo, who were very courteous and professional, and were kind enough to answer any questions I had regarding the install. They did a great job installing our new HVAC system, and were tidy which is always appreciated! Before they left, they explained everything that had been done, and showed me photos of the work.
Our entire experience from start to finish was great. I appreciate that they send photos of who is coming to your home too. Friendly, kind, professional team members, and good work all the way around. Thanks Radiant!
★★★★★
This is the first time I’ve used radiant my neighbor recommended them…. I called them today and they set me up an appointment on the same day. I was totally shocked at that and the service call was only $39!!…. Highly recommend them Danielle showed up and he was a great guy and he put up with all my wishy-washiness and I had to hurry him because I was heading to church and he got caught in a lot of traffic getting here he even would’ve installed the part that broke but I Didn’t have the time tonight….. He was patient with me and just told me to call the office first thing in the morning and get a service call set up…. Thank you so much Radiant!!….
With another cold front coming in tomorrow now I just hope they can get me scheduled for a separate call tomorrow but I have a feeling they will. They are such a great company!!😊😊
With another cold front coming in tomorrow now I just hope they can get me scheduled for a separate call tomorrow but I have a feeling they will. They are such a great company!!😊😊
★★★★★
My unit had been acting funky for a bit and then decided it would shed its mortal coil and go to the next life. I called an another company lets call them company A since I had a warranty with them thinking I could save a few bucks. They showed up 2 hours late of given window. Warranty didnt cover any of the perceived issues ( not really their fault, maybe). Double billed me (why pay 700 for a service call when you can pay 1400!!! ie: they ran my card twice) and then even though issue still wasnt fixed wanted to upsell me some more for close to 3k or get another sweet unit for an overpriced amount.
I'll admit I was getting desperate. Do I let the giant commercial bad guys win? Give them all my money I could be using on fishing gear? My neighbor happens to work at Schmidt Mechanical Group (shout out to Jared) and got me in touch with their service technicians for a 2nd opinion. ENTER Richard Moreno. Showed up at the beginning of time window. Diagnosed the multiple issues in a timely manner. Explained to me what was going on and why and hand held me through what needed to be done now and what to expect in the future. Worked on both of my units. My bill came to a FRACTION of what was recommended by company A. Mr. Moreno was very professional, kind, and honest. As a first time home owner whos been bamboozled by companies like company A, Schmidt Mechanical Group just gained a customer for life. Look forward to doing more business with them and their techs are awesome. Dont be like me and use company A first. Use this company.
I'll admit I was getting desperate. Do I let the giant commercial bad guys win? Give them all my money I could be using on fishing gear? My neighbor happens to work at Schmidt Mechanical Group (shout out to Jared) and got me in touch with their service technicians for a 2nd opinion. ENTER Richard Moreno. Showed up at the beginning of time window. Diagnosed the multiple issues in a timely manner. Explained to me what was going on and why and hand held me through what needed to be done now and what to expect in the future. Worked on both of my units. My bill came to a FRACTION of what was recommended by company A. Mr. Moreno was very professional, kind, and honest. As a first time home owner whos been bamboozled by companies like company A, Schmidt Mechanical Group just gained a customer for life. Look forward to doing more business with them and their techs are awesome. Dont be like me and use company A first. Use this company.
Maintenance Membership
Join the Care Club
Home maintenance for $9.99 a month.
Care Club members get two HVAC tune-ups and a plumbing safety inspection every year, priority scheduling, no dispatch fees — ever — and 5% off every repair.
- Priority scheduling
- Seasonal HVAC tune-ups
- Annual safety inspection
- Exclusive member discounts
- Free dispatch on repairs
- No long-term contracts
Furnace Replacement Questions
What happens to my air conditioner when the furnace is replaced?
In most Central Texas homes the furnace and the air conditioner share one cabinet. The evaporator coil sits on top of the furnace, and the furnace’s blower moves the cooled air all summer. So replacing the furnace means the coil has to come off and go back on, and it has to match the new blower and the outdoor unit. If your coil is the same age as the furnace, or was never a proper match for the condenser, we will tell you and price a replacement coil alongside. If it is in good shape and matched, it stays. Either way, we pressure-test and recharge the refrigerant circuit and confirm the AC runs before we leave, because you will need it again in a few months.
Does a high-efficiency condensing furnace make sense in Texas?
Sometimes, and we will be straight about it. A condensing furnace squeezes more heat out of each unit of gas, but it costs more, needs PVC venting and a condensate drain, and its extra efficiency only pays back in proportion to how much you run it. In Austin or San Antonio, where the furnace may run a few hundred hours a year, that payback is slower than it would be up north. Where a condensing furnace does make sense is a home that runs heat often, one where the old metal flue needs replacing anyway, or a home where the venting route is easy. We will price a standard-efficiency and a high-efficiency option and show you the difference so it is your decision.
Should I replace the furnace and the AC at the same time?
If both are old, usually yes. They share the blower, the coil and the ductwork, and a new furnace paired with a worn condenser and a mismatched coil will not cool the way it should. Doing both at once means one install visit, one matched system with a single warranty start date, and no second trip to pull the coil off again in two years. If the AC is only a few years old and properly matched, replace just the furnace and keep it. A load calculation and a look at the coil tells us which situation you are in. Financing is available for a full system replacement when that is the right answer.
How long does a furnace replacement take?
A straightforward furnace swap in a closet or garage, with the existing coil, venting and gas line staying, typically takes most of a day. An attic installation, a change from an 80% furnace to a condensing furnace that needs new PVC venting and a drain, or a job that includes a new coil and outdoor unit can run into a second day. We tell you the expected time on the estimate, keep the heat off for as short a stretch as possible, and do not leave until the furnace has run a full cycle and the temperature rise checks out. On the coldest nights, we prioritize homes with no working heat.
What size furnace does my home need?
It comes from a load calculation on your actual house: square footage, ceiling height, insulation, window area and orientation, duct condition and the number of people in it. It does not come from copying the BTU rating on the old unit, which may have been oversized from day one. Oversizing is the common mistake in Central Texas. A furnace that is too big satisfies the thermostat in minutes, shuts off, and leaves the far bedrooms cold while cycling its igniter and heat exchanger far more than it should. A right-sized furnace runs longer, quieter cycles and warms the house evenly. We run the calculation for every replacement and will show you the result.
*Offers cannot be combined with other promotions or applied to dispatch fees. No cash value. Must present offer at time of service. Call for details.
