No heat: what a fix costs, fault by fault

A no-heat repair usually costs $150 to $600, and that figure includes the diagnostic visit and the part. The wide band is not padding: an igniter is a $180 part with an hour of labour, while a control board is a $560 part on the same visit. What you pay depends on which link in the ignition sequence failed, and that is why the diagnosis matters more than the hourly rate.

Pricing a no-heat call is really pricing two things: the visit, and the part that fixes it. Separating them is how you tell a fair quote from an inflated one.

The visit itself

Most companies charge a diagnostic fee of $100 to $250, which is the same order as a furnace tune-up and safety check at $100 to $250. Some credit it against the repair if you approve the work; some do not. Ask on the phone, before booking.

If the technician arrives at 11 pm, the fee changes. An after-hours call-out runs $200 to $500 instead of the standard diagnostic. That is the whole emergency premium — the repair itself is not better or more thorough at night.

Cost by fault

The prices below assume a $120 diagnostic and a part plus labour at typical US rates. The total column is the addition, not a range midpoint.

Six of those eight land inside the $150 to $600 band. The last two rows are the reason the band has an upper edge at all, and they are also the repairs that trigger a replacement conversation.

Four worked examples

A furnace that lights and dies. Diagnostic $120, flame sensor cleaned and replaced at $110, total $230. This is the cheapest common outcome and the one most often misdiagnosed as a control board.

A furnace that clicks but never lights. Diagnostic $120, hot-surface igniter $180, total $300. The igniter is a wear item with a five-to-seven-year life in most homes.

A furnace that runs the inducer but never opens the gas valve. Diagnostic $120, pressure switch $260, total $380. If the flue is blocked rather than the switch failed, add a flue clearing charge.

A furnace with heat but no airflow. Diagnostic $120, blower motor $700, total $820. At that number, on a furnace over fifteen years old, get a replacement quote before approving the work.

The pattern is consistent: the diagnosis is roughly a fifth to a half of the bill, and the part decides the rest. A quote that cannot itemise both is not a quote.

The after-hours arithmetic

Take the igniter job above. Daytime: $120 + $180 = $300. At 2 am: $350 + $180 = $530. The premium is $230 for the same part and the same hour of work.

That premium is worth paying when the house is below about 60 degrees Fahrenheit inside, when there is an infant or an elderly resident, or when pipes are at risk. It is not worth paying because the thermostat display is blank at 9 pm on a Saturday — that one can wait until morning, and often turns out to be batteries.

Repair against replacement

The rule of thumb is a third of replacement cost, plus an age test. Replacement runs $3,000 to $8,000 installed. A third of the midpoint is about $1,830, so a $820 blower motor does not trip the rule by itself. Age does.

Two scenarios, same house:

• Eighteen-year-old furnace, $900 repair, expected three more years. $900 ÷ 3 = $300 per year, with no warranty on the rest of the unit.
• Replacement at $5,500, eighteen-year service life. $5,500 ÷ 18 = $305 per year, with a parts warranty and lower fuel use.

Those are close enough that fuel decides it. A 90 AFUE furnace against a 70 AFUE unit uses 70 ÷ 90 = 78 percent of the fuel for the same heat. On a $1,400 annual gas bill that saves $1,400 × 0.22 = $308 a year, which puts replacement clearly ahead. On a $600 annual bill the saving is $132, and the repair is defensible for another few years.

If the ducts are also dirty and restricted, add $300 to $800 for duct cleaning — a separate job that a no-heat diagnosis will sometimes reveal.

Five ways to keep the bill at the low end

1. Check the five homeowner items first. Thermostat, breaker, service switch, filter, gas valve. A call-out for a switched-off service switch still costs $100 to $250.
2. Book a daytime appointment unless the house is genuinely unsafe or unlivable.
3. Ask for the diagnostic fee policy before booking, including whether it is credited.
4. Request the part number and price before approving. A 30-second check of the part online tells you whether the markup is normal.
5. Bundle the tune-up. A $100 to $250 service on the same visit costs less than booking it separately later.

Our guide to no-heat repair options explains which faults are safe to check yourself, and the warning signs guide covers the failures that give notice before the house goes cold. If the furnace is cycling rather than dead, the cost path is different — see short cycling costs.