Heating in Hayward tends to fail on the first cold night of the season, after sitting idle all summer. Winter nights here drop into the 40s, so a house without heat gets uncomfortable fast, especially in the Hayward Hills, where nights are cooler and windier than in the flats. We repair gas furnaces, electric furnaces, heat pumps and hydronic (hot-water) systems, and most no-heat calls trace back to a short list of faults.
How a furnace starts, and where it fails
A gas furnace runs the same sequence every time the thermostat calls for heat. Following that order is how a technician narrows the fault down instead of guessing:
- Thermostat call. A dead battery, the wrong mode or a loose wire means the furnace never gets the signal.
- Draft inducer and pressure switch. A small fan clears the flue and a switch confirms the draft. A blocked vent, a cracked hose or, on a high-efficiency furnace, a clogged condensate drain stops the sequence here.
- Ignition. Many furnaces in 1950s–70s Hayward homes still use a standing pilot; newer ones use a hot-surface igniter or a spark. A pilot that keeps going out or a cracked igniter means no flame.
- Flame sensing. If the sensor rod is coated, the burners light for a few seconds, shut off and try again.
- Blower. A failed motor, capacitor or control board leaves the burners running with little air at the vents.
- Safety limits. If the furnace overheats, usually because of a clogged filter or blocked returns, the limit switch shuts the burners off.
Common heating problems we fix
| What you notice | What usually causes it | What to do |
|---|---|---|
| No heat from the vents, or the system does not turn on | Thermostat, pilot out, ignition failure, tripped switch | Run the safe checks below, then call |
| Furnace runs but the air is cold | Ignition or flame sensor fault, overheating limit, gas supply | Call; leave gas parts alone |
| Rotten-egg or natural gas smell | Leak at a fitting, valve or gas line | Leave the house and call the gas utility or 911 from outside |
| Turns on and off every few minutes, house never warms up | Dirty filter, flame sensor, oversized furnace, thermostat location | Book a diagnostic before the cold sets in |
| Banging at start-up, squealing, rumbling or booming | Delayed ignition, worn blower bearing or belt, burner trouble | Have it checked promptly |
| Soot around the furnace, CO alarm, visible cracks | Cracked heat exchanger or a venting problem | Turn the furnace off and keep it off until inspected |
Short cycling wears out igniters and relays and wastes gas; our guide to a furnace cycling too frequently covers the causes. Banging at start-up is a different worry: delayed ignition lets gas collect before it lights, and repeated small bangs can crack the heat exchanger. For squeals and rumbles, see HVAC noises explained.
When to switch the furnace off and leave it off
A cracked heat exchanger can let carbon monoxide into the air the blower sends through the house. If your CO alarm sounds, you find soot around the burners, or people at home get headaches or nausea that ease outdoors, turn the furnace off, get into fresh air and do not use it until it has been inspected. A gas smell is an emergency: leave first, call the gas utility or 911 from outside, and call us for the repair once the area is cleared. The emergency HVAC page covers the first minutes.
Heat pumps and hydronic systems
A heat pump that blows lukewarm air for a few minutes on a cold, damp morning is often just defrosting its outdoor coil. One that runs nonstop on backup heat, or ices up and stays iced, needs a technician; see heat pump service. Hydronic systems heat water in a boiler for radiators or baseboards; their usual faults are a failed circulator pump, pressure problems and air in the lines.
Safe checks before you call
- Set the thermostat to Heat, a few degrees above room temperature, and replace its batteries if it uses them.
- Look at the filter. A clogged one can trip the overheat limit.
- Make sure the furnace switch (it looks like a light switch, on or near the unit) and the breaker are on.
- Check that the furnace door panel is seated firmly; many furnaces will not run with it loose.
- Move stored boxes, paint cans and laundry away from the furnace. Hall closets and garages tend to fill up.
If those are fine and there is still no heat, stop. Do not keep relighting a pilot that goes out, and do not attempt to repair gas components yourself.
Pricing, parts and brands
You get a flat price after the diagnosis and before any work begins, with no hidden fees. Our technicians carry common parts, so many repairs are finished on the first visit. Repairs come with a warranty, and we use manufacturer-recommended parts. We work on all major brands, including Carrier, Trane, Lennox, Goodman, Rheem, Bryant, American Standard, York, Amana and Ruud.
If the furnace is old and the repairs keep coming, see furnace installation for how we weigh repair against replacement. Between visits, replace filters regularly, keep the furnace area clear and test your carbon monoxide detectors monthly. A yearly fall safety check with HVAC maintenance catches most of these faults early.