Furnace & heating
AC repair
Heat pumps
Ductless mini splits
Carrier
TraneSeasonal tune-up and full diagnostic on your Carrier, Trane, or Goodman system - readings shown to you before any repair is proposed
Diagnosis first, numbers second - you approve the repair price before a single part goes in.
Get your free estimateFast, Reliable Furnace Repair Across Sunnyvale
Furnace repair in Sunnyvale typically runs $150 – $700, with most mid-range issues like ignitor replacement or a blower motor fix landing between $200 and $400. Cold Harbour Heating and Air Dallas gets a live person on the phone 24/7 and routes a technician to Sunnyvale the same day you call. If your heat is down on a cold night off Barnes Bridge Road, you won’t wait until morning to talk to someone who can help.
We know Sunnyvale’s mix of 1980s ranch homes and brand-new custom builds means no two furnace calls look the same. A cracked heat exchanger in a 40-year-old Carrier and a limit switch tripping on a two-year-old Lennox are both Tuesday for us. Call (430) 213-5796 for a written price before any work begins.
Key Takeaways:
- Furnace repair in Sunnyvale costs $150 – $700, with a written price handed to you before tools come out
- Same-day service to Sunnyvale from the Dallas-Fort Worth dispatch office, with crews positioned locally
- Every repair carries the 365-Day Done Right Promise: if it fails within a year, we come back free
Why Cold Harbour Heating and Air Dallas Is Sunnyvale’s Preferred Furnace Repair Company
We’re independently owned and operated, part of the Kingswell network since 2003, and we’ve built our reputation in Sunnyvale by doing exactly what we say we’ll do. Victor Mancini leads our team, and he’s made it policy that every Sunnyvale customer gets a written price before work starts, a firm arrival window, and a clean job site when we leave. That’s not a sales pitch; it’s in writing on every invoice.
Sunnyvale homeowners call us because a live person answers the phone 24 hours a day, 7 days a week. No voicemail trees, no after-hours answering service that promises a callback that never comes. When your furnace quits during a February freeze off Belt Line Road, you get a real dispatcher who can route a uniformed, background-checked technician to your door.
Our technicians are trained to service nine major residential HVAC brands, including Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. That matters in Sunnyvale, where one street can have a 1987 Goodman in a ranch house and a new variable-speed American Standard in the custom build next door. We fix both.
Styles & brands we work with
Boiler Repair in Sunnyvale
Boiler repair in Sunnyvale addresses the hydronic heating systems that some older ranch homes use, and the work costs $150 – $700 depending on the failing component. While most Sunnyvale homes have forced-air furnaces, a handful of properties from the 1970s and early 1980s were built with boilers, and those systems need a tech who understands both their age and the hard water that flows through Sunnyvale’s supply lines. Hard water scale doesn’t just clog pipes; it settles on burners and reduces combustion efficiency, causing short cycling and higher gas bills.
Scale-Choked Burners and Low Water Pressure
When hard water minerals accumulate on a boiler’s gas burners, the flame gets weak and lazy. We see this regularly in older Sunnyvale homes where the original boiler was installed when the neighborhood was first developed. A typical burner clean and descale runs $150 – $300, and it restores proper combustion so the system stops cycling every few minutes.
Circulator Pump and Expansion Tank Replacement
A boiler that heats but won’t move hot water through the radiators usually has a failed circulator pump. In Sunnyvale, we also replace expansion tanks that have waterlogged after years of pressure swings. Depending on the boiler model and whether we need to drain and refill the system, this work sits in the $350 – $700 range, parts and labor included.
Gas Furnace Repair in Sunnyvale
Gas furnace repair in Sunnyvale covers the majority of heating calls we handle, and the job typically runs $150 – $700 depending on the component that’s failed. Most Sunnyvale homes from the 1970s and 1980s were built with gas-fired forced-air furnaces, and those systems are now at the age where heat exchangers crack, ignitors fail, and gas valves stick. Newer custom builds have high-efficiency condensing furnaces with different failure points, like pressure switch faults and drain line clogs.
Ignitor Replacement and Short Cycling
A furnace that clicks but won’t light usually has a dead ignitor. This is one of the most common calls we get in Sunnyvale during the first cold snap, and a typical ignitor replacement runs $150 – $280. Short cycling, where the furnace fires and shuts off repeatedly, often points to a clogged flame sensor or restricted airflow from dirty filters paired with undersized ductwork in older homes.
Heat Exchanger and Gas Valve Issues
If you smell gas or your carbon monoxide detector is going off, leave the house and call us from outside. Broken heat exchangers in 30- to 40-year-old furnaces are a serious safety issue we test for on every repair call. A replacement heat exchanger runs $400 – $700 when parts are available, but depending on the system’s age, we may recommend full replacement and give you honest numbers for both options.
Trusted Brands We Service in Sunnyvale
Our technicians are trained on nine major residential HVAC brands, and in Sunnyvale that means we’re more likely to have common parts for Carrier and Lennox systems already on the truck when we pull up. For Daikin and American Standard units, we source factory parts through our Dallas-Fort Worth supply chain and can typically have them in Sunnyvale within a day. Furnace Repair is what we do every day, but brand-specific knowledge is what keeps us from guessing at your system’s wiring and controls. We’d rather replace a part once with the right component than return three times with the wrong one.
Common Furnace Repair Problems We See in Sunnyvale Homes
- Storm-surge damage to control boards: Summer thunderstorms roll through Sunnyvale with lightning that hits power lines and sends voltage spikes into furnace electronics. The furnace runs fine for months, then fails on the first cold snap when the blower control board won’t respond, leaving a fully functional gas furnace that won’t start.
- Hard water scale on burners: Sunnyvale’s water supply carries enough dissolved minerals to coat gas burners over a season or two. The scale disrupts the flame pattern and causes the burner to short cycle, which most homeowners notice as heat that runs for five minutes, shuts off for ten, then repeats.
- Attic heat exchanger rust: Newer Sunnyvale homes often have furnaces installed in unvented or poorly vented attics, where summer humidity climbs. That moisture condenses on cool metal surfaces and rusts the heat exchanger from the outside in, eventually tripping carbon monoxide sensors before it fails inspection.
- Static pressure problems on new systems: Custom homes in Sunnyvale’s new subdivisions often pair a high-efficiency furnace with existing ductwork that wasn’t sized for the new unit. The furnace’s blower motor works against high static pressure, the limit switch trips, and the homeowner thinks the new system is broken when it’s actually airflow.
See the difference
Before
After
Before
After
Before
AfterPricing for Furnace Repair in Sunnyvale, TX
| Repair Type | Typical Price in Sunnyvale |
|---|---|
| Gas Furnace Repair | $150 – $700 |
| Ignitor Replacement | $150 – $280 |
| Flame Sensor Cleaning | $90 – $160 |
| Blower Motor Replacement | $300 – $550 |
| Heat Exchanger Replacement | $400 – $700 |
| Boiler Repair | $150 – $700 |
These are what Sunnyvale homeowners actually pay for the repairs we handle, parts and labor included. The written price we hand you before work starts is the price you pay; it doesn’t change at the door, and it’s covered by the Furnace Repair in Sunnyvale pricing structure we use across the area. Call (430) 213-5796 for a free estimate and an honest diagnostic.
We Also Serve Cities Near Sunnyvale
If you’re in Sachse, Irving, Dallas, or Addison, the same team that serves Sunnyvale covers those neighborhoods too. Dispatch runs out of our Dallas-Fort Worth office, and crews are positioned to reach Sunnyvale and surrounding towns without long waits. Call us from anywhere in the eastern Dallas suburbs and ask for a same-day appointment.
Serving Sunnyvale, TX - Our Local Coverage Area
We’re based in the Sunnyvale area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Furnace Repair in Sunnyvale
Short cycling after a storm usually means a power surge damaged your furnace’s control board or flame sensor. Sunnyvale’s electrical grid takes hits from summer lightning, and those voltage spikes don’t always kill electronics instantly; sometimes they weaken a component so it fails months later when the furnace is finally called to run. Call (430) 213-5796 and we’ll test the board and sensor, usually for less than $200.
You may notice a yellow, flickering flame instead of a steady blue one, soot buildup around the furnace, or a carbon monoxide detector that keeps tripping. Cracks often start as hairline fractures that expand with thermal cycling, and they’re not always visible without a camera inspection. Our techs inspect the heat exchanger on every furnace repair call in Sunnyvale, and we’ll show you the footage if we find a problem.
In Sunnyvale’s new custom builds, the furnace often gets paired with ductwork that wasn’t sized correctly for the new system’s airflow requirements. High static pressure makes the blower motor work harder, which overheats the limit switch and shuts the furnace down as a safety measure. The fix is usually an airflow correction like a larger return or a blower speed adjustment, not a new furnace, and it typically falls in the $150 – $400 range depending on what we find.
Yes. If your HVAC system is a heat pump or a dual-fuel setup, the outdoor condenser flooded in a storm may have taken on water and debris, and switching it back on without inspection can cause electrical shorting and compressor failure. We recommend having the unit inspected and dried before restoring power; call us for a condenser check and we’ll also look at the furnace side - or our AC Repair in Sunnyvale - while we’re there.
Yes, we recommend a dedicated surge protector on your furnace’s electrical line, especially given Sunnyvale’s summer storms. A small investment of $150 – $400 protects the control board and other sensitive electronics from the voltage spikes we see routinely in this area. It’s cheaper than replacing a fried control board, and our techs can install one during your next tune-up.
Call Cold Harbour Heating and Air Dallas for Furnace Repair in Sunnyvale
When your furnace quits on the coldest night of the year, you don’t need a call center that’ll get back to you in 24 to 48 hours. You need a live person on the phone, a technician who knows Sunnyvale’s old and new housing stock, and a written price before the first tool comes out. That’s the Kingswell Way, and we’ve been doing it since 2003. Call Victor Mancini’s team at (430) 213-5796 for a free estimate and a firm arrival window. We serve all of Sunnyvale, from the ranch homes off Barnes Bridge Road to the new builds off Collins Road, with same-day service and the 365-Day Done Right Promise on every repair.
Written by Victor Mancini, Owner at Cold Harbour Heating and Air Dallas, serving Sunnyvale since 2003.