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San Antonio Heating
Nine Months Off, Then Everything at Once
A San Antonio heating system has an odd life. It sits idle from March until the first real cold front, usually sometime in November or December, and then it is asked to start on a night when the whole city is asking the same thing. Dust has settled on the burners, a flame sensor has oxidized, a heat pump has not run a defrost cycle in nine months. Most of the heating calls we get land in the first 48 hours of the first freeze, and nearly all of them could have been found in a fall tune-up.
Winters here are mild, which is exactly why the exceptions hurt. February 2021 put much of the metro below freezing for days, and homes with marginal furnaces, heat pumps stuck on auxiliary heat, or thermostats wired wrong found out the hard way. San Antonio housing is split between gas furnaces, common in older neighborhoods and many north-side subdivisions, and all-electric heat pumps or electric furnaces, common in newer developments and across the northeast side toward Converse, Schertz and Universal City. We service both, and we have since 1999.
Our furnaces and heat pumps pages explain how each type of system works and what goes wrong. Below is how that plays out in a San Antonio winter.
- Gas and electric Gas furnaces, electric furnaces with heat strips, heat pumps and dual-fuel systems.
- Staffed through the freeze When a hard freeze hits Bexar County, we run 24/7 at the same pricing as a Tuesday afternoon.
- Fall tune-up with Care Club Two annual HVAC tune-ups on an enrolled system, one of them before heating season, for $9.99 a month.
First Cold Night
What San Antonio Heating Systems Do When They Wake Up
A few of these are normal for a day. The rest are worth a call before the next front.
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A burning-dust smell for the first hour
Normal on the first run of the season as dust burns off the heat exchanger or heat strips. If it lasts past a day or smells electrical, shut it off and call.
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The blower runs but the air is cool
On a furnace, an ignition or flame-sensor fault. On a heat pump, a failed reversing valve or a unit stuck in cooling mode.
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It starts, stops, and starts again every few minutes
Short cycling. A dirty filter, a failing limit switch, or a furnace that is oversized for the house.
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The “aux heat” light is on all the time
A heat pump leaning on its electric strips. Fine during a hard freeze, expensive on a 50-degree morning. Usually a refrigerant or control problem.
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A carbon monoxide alarm, or a yellow flickering flame
Leave the house and call from outside. A cracked heat exchanger or bad venting on a gas furnace is a safety issue, not a comfort one.
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The back bedrooms never warm up
Duct leaks or a failed damper in the attic. The same problem that made those rooms hot in August.
What We Do
Heating Services Across the San Antonio Area
Repair, maintenance and replacement for every kind of heating equipment found in San Antonio homes.
- Furnace repair Ignitors, flame sensors, pressure switches, boards and blowers, on gas and electric furnaces.
- Heat pump service Reversing valves, defrost controls, auxiliary heat and the refrigerant side that does double duty here.
- Fall heating tune-ups Burners cleaned, heat exchanger inspected, safeties tested and the system run before you need it.
- Furnace replacement When the heat exchanger is cracked or the unit is simply done. Sized for the house, permitted, and manager-reviewed over $3,000.
- Dual-fuel systems A heat pump for the mild days and a gas furnace for the rare hard freeze. A good fit for the way San Antonio winters actually behave.
- Thermostats and controls Correct wiring for heat pumps and auxiliary heat, and smart controls that stop the strips from running when they should not.
How It Works
A Heating Call With Radiant
The same approach for a no-heat emergency at 3 a.m. and a scheduled October tune-up.
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Call, day or night
During a freeze, houses with no heat and children, older adults or medical equipment come first. No after-hours surcharge.
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Safety first, then diagnosis
Gas furnaces get a heat exchanger and venting check before anything else. Then we find the actual fault.
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Price in writing
Honored for 72 hours, no hidden fees. If the furnace is at the end of its life, we show you replacement numbers too and let you choose.
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Fix, test, verify
We run a full heating cycle, confirm the thermostat is calling correctly and check for CO before we leave.
Current Specials
Save on the work your home needs most.
San Antonio
HVAC
25% Off Select Air Purifiers & Filters
Expires 12/31/2026
San Antonio
HVAC
Up To $2,500 OFF Full HVAC System!
Expires 12/31/2026
San Antonio
HVAC
Buy a Complete HVAC System, Get a Furnace FREE!
Expires 12/31/2026
San Antonio
HVAC
Last Chance HVAC Tune-up $68
Expires 12/31/2026
Both Locations
HVAC
Up to $200 off Duct Cleaning
Expires 12/31/2026
Both Locations
HVAC
$99 Furnace Tune-Up
Expires 12/31/2026
No Heat in San Antonio?
We are staffed through every cold front, at the same price as a warm afternoon.
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
San Antonio Heating Questions
Do I really need a heating tune-up in a city with winters this mild?
The mildness is the reason. A furnace or heat pump that has not run since March is the one most likely to fail on the first cold night, because nothing has tested the ignitor, the flame sensor, the defrost board or the heat strips in nine months. A fall tune-up runs the system under load, cleans the burners, checks the heat exchanger for cracks, tests the safeties and confirms the thermostat is calling for heat the way it should. It takes about an hour. It also matters for safety: a gas furnace that has sat idle can have venting problems that only show up when it fires. Care Club covers this visit as one of two annual tune-ups on an enrolled system.
What should I do if the heat goes out during a hard freeze like February 2021?
Call us first; we run 24/7 through freezes and prioritize homes with no heat. While you wait, keep interior doors open to spread whatever warmth remains, run faucets at a trickle to protect pipes, and never use a gas oven, grill or portable generator indoors for heat. Carbon monoxide poisoning is the real danger in a prolonged freeze. If you have a heat pump, switching the thermostat to “emergency heat” will run the electric strips directly, which is expensive but works when the outdoor unit cannot. If your furnace has power but will not light, check the filter and the breaker before anything else. Our frozen pipe repair page covers the plumbing side of a freeze.
Should I replace my old gas furnace with a heat pump in San Antonio?
For many San Antonio homes, it makes sense, because the cooling load is enormous and the heating load is small. A heat pump is an air conditioner that can run in reverse, so you replace both halves of the system at once and get efficient heat on the 45-degree mornings that make up most of our winter. The trade-off is capacity during a hard freeze, when a heat pump leans on electric strips. A dual-fuel setup that keeps a gas furnace as backup avoids that. If your furnace is younger than ten years and working well, keep it; there is no reason to replace working equipment. We will run the numbers both ways in writing. Our San Antonio heat pump page goes deeper.
Why is my electric bill so high in winter when I barely run the heat?
If your home has a heat pump, the likely answer is auxiliary heat running more than it should. The electric strips are meant to kick in only when the heat pump cannot keep up, such as during a hard freeze or a big thermostat jump. A low refrigerant charge, a failed outdoor fan, a stuck reversing valve, a bad defrost board or a thermostat wired incorrectly can leave the strips running on mild days, and they use several times the electricity the heat pump would. If the “aux” or “emergency heat” indicator is on when it is 55 degrees outside, that is the sign. It is one of the most common heating repairs we make in all-electric neighborhoods across the northeast side.
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