Tempstar furnaces, central air conditioners and heat pumps are straightforward, value-priced equipment, often chosen for budget-focused builds and replacements. In Hayward that can be a Tempstar furnace in the hall closet of a 1960s house or a Tempstar condenser behind a newer townhome. The parts inside are standard and easy to get; the work is in finding which one failed. We are an independent service company, not affiliated with Tempstar, ICP or Carrier.
Part of the ICP family
Tempstar is made by ICP, the company behind Heil and Comfortmaker, and ICP is owned by Carrier. The brands share much of their engineering, so a Tempstar and a Heil furnace of the same type can take the same igniter or control board. That is why Tempstar parts are readily available. The name on the cabinet matters less than the model number on the data plate, which is what we order from.
Tempstar furnaces: read the status light first
Most Tempstar gas furnaces have a status light on the control board behind the blower door, often visible through a small window, and a chart on the door that explains the flash codes. Count the flashes before you turn the furnace off; cutting the power erases the code. The faults we see most:
- Flame sensor. The burners light, then go out after a few seconds. Cleaning or replacing the sensor fixes it.
- Pressure switch. The inducer runs but the burners never light. On a high-efficiency furnace a blocked condensate trap or drain hose is a frequent cause; on any furnace, a blocked vent or a weak inducer.
- Limit switch. The furnace heats, shuts off early and repeats. That usually means poor airflow: a clogged filter, closed vents or a weak blower. Our guide to furnace cycling too frequently goes deeper.
- Igniter. The inducer runs, the igniter never glows, and the furnace locks out after a few tries.
Outdoor units: the standard ICP wear items
| What you notice | Likely cause | What it usually takes |
|---|---|---|
| Fan still, unit humming | Weak or failed capacitor | Capacitor test and replacement |
| Indoor fan runs, outdoor unit silent | Pitted contactor or a thermostat wiring fault | Contactor and low-voltage circuit check |
| Outdoor unit keeps running after the thermostat is off | Contactor stuck closed | Switch it off at the breaker; contactor replacement |
| Heat pump coil iced over in winter | Defrost control or sensor | Defrost cycle test |
| Short, frequent cycles | Thermostat, oversized unit or refrigerant problem | Testing first; see short cycling |
What a Tempstar tune-up checks
Annual maintenance is what gets the most life out of value equipment. Our yearly visit covers:
- Furnace: burner flame, igniter and flame sensor, inducer and pressure switch, venting, the condensate trap on high-efficiency models, the visible parts of the heat exchanger and a carbon monoxide check.
- Air conditioner or heat pump: capacitor measured against its rating, contactor contacts, outdoor coil cleaned, refrigerant performance and, on a heat pump, a defrost test.
- Both: filter, thermostat and blower.
Each of these wears with every cycle, and finding a worn part on a scheduled visit beats a breakdown call. The full list is on our HVAC maintenance page.
Warranty and parts
Tempstar, like the other ICP brands, offers a longer parts warranty on registered equipment and a shorter base term otherwise; the certificate for your model has the details. The coverage is for parts. Labor is separate unless an extended labor plan was bought with the system. Our repairs carry a warranty, and we use manufacturer-recommended parts.
Repair or replace
A flame sensor, igniter, capacitor, contactor, inducer or control board on a sound system is a repair. A cracked heat exchanger in an older furnace is the clearest case for replacement: it can let combustion gases into the airstream, so the furnace should not be run. Hill homes, which run cooler and windier than the flats, may need more heating capacity than the original furnace had, so a replacement there should be sized for the house, not copied from the old label. See furnace installation.