When a furnace acts up as the nights get cold, the big question is whether to fix it or replace it. Here is a simple way for San Fernando Valley homeowners to think it through before calling a contractor.
Rather have a licensed HVAC pro handle it?
Free referral to a licensed local HVAC pro. A real person calls you back, 7 AM – 8 PM, 7 days a week.
Signs a repair makes sense
- The furnace is fairly young: many gas furnaces last roughly 15 to 20 years. If yours is well under that, a repair is often the better value.
- It’s a single, common part: igniters, flame sensors, thermostats, blower motors and pressure switches are routine repairs.
- It has been reliable: no breakdowns in recent winters and heating bills haven’t jumped.
- The heat exchanger is sound: the contractor finds no cracks or rust-through.
Signs it may be time to replace
- Age: the furnace is near or past 15 to 20 years old and needs a major part.
- A cracked heat exchanger: this part keeps combustion gases separate from the air you breathe. A crack is a safety issue, and on an older furnace it usually means replacement. See carbon monoxide and furnace safety.
- Repairs keep coming: several service calls in the last couple of winters.
- The repair costs a big share of a new unit: a common rule of thumb is to think hard about replacing when one repair approaches half the cost of a new furnace, especially on an older unit.
- Comfort problems: uneven rooms, short cycling or a furnace that runs constantly without keeping up.
Not sure what is wrong yet? Start with furnace won’t turn on: 7 quick checks or heater smells like burning.
Think about the whole system
In the Valley, the furnace often shares ductwork with the air conditioner. If your AC is also old, ask about replacing both together, or about a heat pump that heats and cools. Our guide to heat pumps vs. furnaces in the Valley explains the trade-offs, and repair or replace your AC covers the cooling side.
Permits and safety
Replacing a furnace generally requires a permit (in the City of Los Angeles, from LADBS; other cities like Burbank and San Fernando have their own building departments). A licensed contractor should pull it. Be cautious of anyone who suggests skipping it. If you ever smell gas or your carbon monoxide alarm goes off, leave the house and call the gas company or 911 from outside.
Questions to ask the contractor
- Are you licensed with the CSLB and insured? You can check at CSLB.ca.gov.
- What exactly failed, and can you show me?
- How old is my furnace, and is the heat exchanger in good shape?
- Can you give me both a repair price and a replacement price?
- For a replacement: does the quote include the permit, a properly sized unit, venting, the thermostat and haul-away? What are the warranties?
Need a licensed pro?
Want a second opinion or a replacement quote? We will connect you with an independent, licensed local contractor. It is free for homeowners. See furnace repair and heating installation.
Near you: HVAC service in Sunland-Tujunga · HVAC company in Calabasas · HVAC services in Mission Hills
More HVAC tips
Valley HVAC Network is a free referral service, not an HVAC contractor. All work is done by independent contractors licensed by the California CSLB. Learn how it works.
Prefer a callback?
Leave your name and number and a real person will call you back to connect you with a licensed local HVAC contractor. It’s free for homeowners, with no obligation. Or call (818) 658-2668.