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No Heat in the House? What to Do With Your HVAC System

Waking up to a cold house in the middle of winter is stressful—and sometimes alarming.
When your heat suddenly stops working, the problem may be simple, or it may require professional HVAC repair.
At Twintech Heating & Cooling, we help homeowners restore heat quickly and safely.
If you have no heat in your house, here’s what to do before—and when—to call an HVAC professional.
Step 1: Check Your Thermostat First
Before assuming the worst, start with the thermostat.
Make sure:
It’s set to HEAT, not COOL or OFF
The temperature is set higher than the current room temperature
Batteries are fresh (if applicable)
The display is on and responsive
If the thermostat isn’t sending a signal, your HVAC system won’t turn on.
Step 2: Check the Circuit Breaker and Power Supply
Your furnace or heat pump needs power to operate.
Look for:
Tripped breakers labeled “furnace,” “air handler,” or “HVAC”
A shut-off switch near the furnace that may have been turned off
A blown fuse if your system uses one
Reset a tripped breaker once.
If it trips again, stop and call a professional.
Step 3: Inspect the Air Filter
A clogged air filter can restrict airflow enough to shut down your heating system as a safety precaution.
If the filter looks dirty:
Replace it immediately
Restart the system
Wait a few minutes to see if heat returns
In winter, filters often need replacing every 30–60 days.
Step 4: Look for Furnace Error Codes
Many modern furnaces have a blinking light or digital display that shows error codes.
These codes can indicate:
Ignition failure
Flame sensor issues
Pressure switch problems
Airflow restrictions
If you see a code, note it—but don’t attempt repairs unless you’re trained to do so.
Step 5: Check the Pilot Light or Ignition (Gas Furnaces)
If you have a gas furnace:
Make sure the gas valve is on
Check whether the pilot light is out (older systems)
Listen for ignition attempts
If you smell gas, leave the home immediately and contact your gas provider or emergency services.
Step 6: Check Outdoor Units (Heat Pumps)
If you use a heat pump:
Make sure the outdoor unit isn’t buried in snow or ice
Clear debris and ensure airflow
Allow time for defrost cycles to complete
Heat pumps may blow cooler air during defrost—this is normal—but they should not stop heating altogether.
When Not to DIY
Stop troubleshooting and call a professional if:
The system repeatedly shuts down
You hear loud banging, screeching, or grinding
There’s a burning or gas smell
Breakers keep tripping
The system turns on but never produces heat
Continuing to reset or restart a failing system can cause further damage.
How Twintech Can Help Restore Heat Fast
At Twintech Heating & Cooling, we prioritize no-heat calls because we know how urgent they are.
Our technicians quickly diagnose the issue, explain your options clearly, and get your heat back on safely.
Whether it’s:
Furnace repair
Heat pump troubleshooting
Emergency heating service
System replacement
We’re here when your home needs heat the most.
Great service and great people to deal with, from sales to installer. I highly recommend this company.
Twintech replaced our aging furnace and air conditioner recently. I highly recommend this company. Their quote was competitive, they were on time and respectful of our home and extremely professional. From the salesman to the installers and the owner who followed up afterward to ensure we were satisfied, we are very pleased with the service. We are looking forward to working with this company for all of our HVAC needs for the years to come. Excellent workmanship and service!
We wanted to get our AC replaced as it was 22-years old and added to this our furnace was costing more and more to repair. So, we decided to get both the furnace and AC replaced.
After going through a few quotes and product reviews we decided to go with Twintech. The three-men crew arrived early in the morning, wasted no time and got to work right away. By 2:00 pm, they were all done. Ive found their work to be top notch and they were completely professional. I had all my questions answered to my satisfaction both during the progress of their work and at end.
I have pleasure in recommending Twintech to anyone who is looking to get their furnace or Ac replaced
Nathan S.
Our air conditioner died On a Saturday and within hours Dave came out to take a look and discuss replacement/repair options.
The new air conditioner was installed on the Wednesday. The new unit was installed quickly. The installers were friendly and cleaned up afterwards.
We noticed a slight leak around the furnace that night and they came out the next day and fixed the issue. It has been working great and is quieter than our previous unit.
Very satisfied and would highly recommend TwinTech.
I contacted TwinTech to replace my 20-year old A/C. Dave, their service rep, promptly replied and was at my home within 2 hours. He was friendly and knowledgeable and didn't try to upgrade or oversell their A/C units but suggested the best fit for my small 1000 feet bungalow. Although this was during a heatwave and very busy, they were able to fit me in 2 days later. The TwinTech crew installed a 1.5 ton Ducane A/C unit that is now running smoothly while maintaining a constant cooling temperature. The crew were very courteous, professional and efficient and I will definitely recommend TwinTech to family and friends. I much appreciated your great service.
Nancy M., Oshawa
We had a great experience. The guys who installed our a/c did a nice job. Cleaned up.
excellent crew, fast and efficient! Would call them again when I need a new furnace.
Professional, courteous and efficient, dont need to say more than that! Use them you will not regret it.
TwinTech was a pleasure to deal with from the estimate through installation. We replaced a 28 year old a/c unit with one recommended by TwinTech's sales representative Dave who took the time to go over the product with us and answer any questions. The warranty is for 10 years parts and labour and they will complete the registration for you. Installation was by Greg (owner) and Mitch and Spencer who were quick and efficient and left everything clean and tidy.
Very professional, from the sales consultation and inspection to the final installation. Met every expectations we had for the job. A local business with great client support. We highly recommend. Twintech is a blue chip! Thanks!
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We are very happy to recommend this company to everyone. Our furnace broke down on Sunday morning. We phoned them and before noon Grant the owner showed up. He worked on the furnace for about a hour not wanting to give up to fix the problem. The furnace was 17 years old. I was the one talking about replacing it. End result was the next day it was all done. On the Sunday Bob came over with heaters to warm up the house. We decided to replace the water heater at the same time. Thanks Grant for the excellent work. Thumbs up.
Right on time. Explained how to work the HRV in a different way so the house would not be so dry. Changed my whole house water filter for me as well. Friendly, helpful, caring service!
Very pleased with the professional service that TwinTech Heating and Cooling provided in replacing my furnace. I got several quotes from different service providers. Their price was excellent and they explained the features very well. We are very glad we went with TwinTech and highly recommend their services.
We were new homeowners in need of a second opinion. TwinTech Heating & Cooling were Amazing and professional. Very knowledgeable and great service all around. Recommend to anyone looking for honest and reliable services. Treated with respect and care. Thank you Greg, Mitch and Bob!
TwinTech is an excellent and honest company! I called them for a second opinion after being told by another company that I needed to replace my furnace. Turns out this was not the case at all! I did not need a new furnace. TwinTech did not push to make an unnecessary sale and saved me from a huge expense. Bob and Mitch were extremely professional and above all honest! I definitely recommend TwinTech!
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