Heater Not Working? Heater Blowing Cold Air? Heat Not Turning On?

Lots of people in San Antonio TX are asking that question right now. Here’s what might be happening and what to do about it!

First of all, don’t call a pro just yet. And don’t try amateur fixes on your heating, AC or plumbing such as using glue like Elmer’s for home services. Try this first. Here are a few simple checks you can do to see if you can fix your heater problems without a professional. If these don’t work, then you can give Air & Plumbing Today a call for a fast affordable heater repair service.

To start us off, you must know that a malfunctioning home heater is not only uncomfortable, it could lead to costly damage—including pipes freezing and bursting. Very cold temperatures inside your home and the resulting condensation can potentially damage your windows, and it’s possible for a house that’s unheated through the freezing winter months to even succumb to structural damage. Getting your heater to operate properly during cold weather is a big deal and should be handled immediately, and you may or may not have to call a professional heating of furnace repair professional depending on what you find. If your heater quit working, there are a number of solutions to heater problems that you can look at, including setting the thermostat and, if you have a gas model, reigniting the furnace’s pilot light. Read on for some quick and easy troubleshooting tactics to try before calling a professional service technician. With that said, stop your shivering and follow these easy steps:

Make sure your thermostat is on.
The most obvious solution for a furnace not turning on is frequently overlooked when troubleshooting heating systems: Many folks neglect to check the thermostat, the part of your heating system that assesses the room’s temperature and allows you to set and adjust the desired temperature. A thermostat is typically installed on one of the main walls in your home, a little higher than a light switch.

If your thermostat won’t turn on, the device can’t tell the heater or furnace when to turn on. So, if you have a programmable thermostat, check to ensure the display is active, the furnace is on, and the unit is set to heat. If you have a manual thermostat, note that during dusting or other household cleaning chores, the switch can accidentally get knocked into an “off” position. Once you’ve found that the thermostat is on, turn the heat up to a temperature that typically causes the furnace to switch on, this temperature can vary from thermostat to thermostat. If the heat doesn’t kick on after a minute or so, increase the temperature setting significantly as you continue troubleshooting.

No power to your thermostat

Does your thermostat use batteries?
If your thermostat doesn’t have power, AND it uses batteries, try replacing them.

Still no power to your thermostat?
If your thermostat has no power and the display is off, here’s what may be happening. In San Antonio Texas winters, the weather can cause your system to use both the heater and the air conditioning on the same day when the temperatures change from cold to hot. In this environment, your AC drain lines can get clogged, not allowing the AC condensation to drain out of the catch pan underneath your air conditioning unit. If that pan fills up with water, there’s a switch that cuts off power to your thermostat to prevent water from spilling out and causing water damage to your home. Unclogging these drain lines will solve your problem. Most of the time, this issue calls for a professional HVAC technician.

Heater not turning on – gas systems.

Make sure that your gas is turned on.
Any gas furnace will have a valve or gas cock located within 6 feet of the unit. Furnace valve designs vary, but they often include a little disk with a small handle or lever on it. Some gas valves can look like little boxes, while still others can resemble a lever about the size of your index finger (often brightly colored like red or yellow).

The valve may have been closed by accident or by someone working on the furnace who forgot to turn it back on. While valves might vary depending on make or manufacturer, a gas valve will typically be in the open position—which means there is gas flowing through the pipe—if the handle on the valve is parallel with the pipe. If the handle is perpendicular to the pipe, the valve is probably closed. To open it, turn the little handle so that it’s parallel to the pipe.

If the furnace or heater still doesn’t kick on once the valve is open, check another gas appliance in the house, such as a stove or fireplace, to see if it’s still working. If the other gas appliances don’t turn on, you may not have gas coming into your home. This can be the result of crews working somewhere on the gas line, or there might be a gas leak, a break, or even a blockage in the line. A gas leak can be a dangerous situation, so if you suspect this to be the case, call 911 immediately and follow their instructions.

To get better insight to your gas situation, go outside and check the street-side valve and then the internal house-side valve to see if they are on. If they are not on, turning the valve to the open or “on” position (as described above) should get gas flowing into your home once again. If your furnace and other gas appliances still won’t turn on, contact CPS or your gas utility company to find out if they’re working in your area or if there have been any service interruptions. If that’s not the case, check the status of your account, too. Whether due to a technical glitch or whatever, a missed or incomplete utility payment can result in a service interruption. But the good news is you won’t need a professional to fix that situation.

Check your heater’s power switch.

Sometimes the reason for a heater not turning on is because it’s simply turned off. Locate the power switch on the furnace itself, which is likely on a wall, on a ceiling or the floor near the unit. It will often look like a regular light switch and it may or may not be labeled. Typically, but not always, the “on” position is up, although this will depend on the installation. It’s easy for someone unfamiliar with the house to accidentally turn the furnace off, mistaking it for a light switch. Flip this switch back to the “on” position and wait for the unit to start up. Some furnaces can take several minutes before they resume functioning. Sometimes people who are storing stuff in their attic can accidently bump the power switch and not know it.

Replace dirty air filter.

A clogged air filter will stop a heater from heating properly. Over time, an air filter can become clogged with dust, hair, or other household debris, making your heating system less efficient. As well, restricted airflow can cause the heat in the heat exchanger to continually increase. Every furnace has limit switches that activate when temperatures exceed a certain point, shutting down your heater. To keep the unit functioning properly, heater or furnace air filters should be replaced every 1 to 3 months, regardless of any heating or air-flow issues.

To find your heater system filter, locate the spot where air flows into the furnace when it is working. Slide the old filter out and examine the side for a model number and size so you’ll know which replacement filter to buy. When replacing the air filter, check the frame for an arrow mark, which indicates the direction the air is flowing. As you slide the new heater filter into place, be sure to position the arrow so that it faces the heater.

Furnace not turning on. What a professional might check when they arrive:

Heating system pros often check the ignition sensor on gas-powered heaters and furnaces.

The ignition sensor is a safety device that detects whether the furnace is burning gas. The sensor uses the increasing temperature in the furnace to identify flames. If the sensor cannot detect a flame, it will shut down your heaterto prevent unburned gas from escaping into your home which can be dangerous. Residue buildup can stop the flame sensor from operating correctly. Cleaning it can allow the furnace to turn on and function properly. This may also be time to call a pro. To get an idea of what’s involved, consider these basic instructions for cleaning the ignition sensor:

Before an HVAC pro cleans the sensor, they will shut off your heater. Some furnaces don’t have an on-off switch, so to turn it off, find the gas valve that controls the gas going into your furnace, and turn the little handle on the valve to the closed or “off” position (perpendicular to the pipe).
Then, they typically look for a porcelain base with a small metal rod in front of the pilot light inside the furnace. They’ll use a screwdriver with the appropriate head to loosen and remove the screw beside the sensor and then slide the dirty sensor out from its current position.
HVAC pros will clean the metal rod with a wad of steel wool or a clean, straight-edged knife to remove any residue or buildup.
Once clean, they then slide the sensor back into position, replace the screw that holds the sensor, and turn the gas back on. If you’re pretty handy, you could give this a try.

However, if after trying these solutions your furnace still doesn’t turn on, it may be time to consider calling in a heater repair professional. Book a repair with Air & Plumbing Today either online or call 210-519-5959.