Why is my furnace not heating?
A furnace that won't heat is most often a dirty filter choking airflow, a failed igniter, or a thermostat problem — in that order of cheapness. A furnace that starts, runs a minute, then stops is usually a dirty flame sensor. True no-heat in deep cold justifies the after-hours call; a mild-weather failure usually doesn't.
Likely causes
- Clogged filter — Restricted airflow overheats the furnace until the safety switch shuts it down.
- Failed igniter — Modern furnaces light with a hot-surface igniter that cracks every 5–7 years. Clicking with no flame points here.
- Dirty flame sensor — The furnace lights, runs a minute, and quits — the sensor can't prove flame, so it shuts down safely.
- Thermostat or power issue — Dead thermostat batteries, a tripped breaker, or an open furnace door switch — check before you pay for a visit.
What you can check yourself
- Replace the filter, and confirm the thermostat is on 'heat' with fresh batteries if it uses them.
- Check the breaker and the furnace's own power switch (it looks like a light switch, usually near the unit).
- Make sure the furnace access door is fully closed — many units won't run with the door switch open.
Typical cost
Typical repairs in Richmond, VA: service call $100–$250; igniter $150–$350; flame sensor cleaning/replacement $150–$300; blower motor $400–$800.
When to call a pro
Gas smell, a carbon monoxide alarm, or a furnace that short-cycles with a burning smell — leave and call from outside. Otherwise, no heat below ~40°F with kids or elderly at home counts as urgent.
HVAC pros in Richmond, VA
- Hungerford Heating & Cooling · 1604 E Broad St, Richmond, VA · 18046484703
- Armstrong Mechanical Services Inc · 1011 E Main St Ste 214, Richmond, VA · 8045412622
- Kelleher Hvac · 1301 School St, Richmond, VA · 18046497501
- Tuckahoe Heating and Cooling LLC · 1129 Gaskins Rd #202, Henrico, VA · +15402933975
- Booker Heating And Air Conditioning, LLC · 1723 Byron St, RICHMOND, VA · 8046525971
- Commonwealth Heating And Contractors Inc · 3200 Milburn Ave, Richmond, VA · +18042221365
- Samson Insulation · 1321 Maxie Ln, Richmond, VA · (804) 373-7196
- 1st Due Solutions, LLC · 4248 Oakley Ct Ste H, Richmond, VA · 8048522279
Get free quotes from Richmond, VA pros →
Data by Servik — verified local pros from official license records and public sources. Cost figures are typical ranges, not quotes; a pro's written estimate is the real number.