No Heat in Santa Clarita, CA

Is it the heat pump or the gas furnace?

Many Santa Clarita homes have both - a Mitsubishi inverter heat pump that handles most of the mild SCV winter, and a builder gas furnace as backup or in a separate zone. Diagnosis starts by figuring out which one is supposed to be running and what it is flashing. A heat pump talks through the indoor green LED and the P/E/U code; a gas furnace talks through a control-board flash code you read at the unit. Knowing the equipment saves an hour of chasing the wrong system.

Why does my Mitsubishi heat pump blow cool in heat mode?

Two normal reasons and two faults. Normal: it is in a defrost cycle clearing frost off the outdoor coil, or it is in heat preparation - both can briefly feel cool, and a slow steady green blink often signals exactly that. Faults: a stuck reversing valve that will not flip the refrigerant flow into heating, or low refrigerant from a flare-joint leak that shows up worse in heat mode (often a P8 pipe-temp or U7 low-superheat code). We check the reversing valve solenoid and the pipe thermistors, then verify charge.

What do the furnace flash codes mean?

On a Trane integrated furnace control, 2 flashes is a system lockout, 3 is a vent/pressure-switch error, 4 is an open high-temperature limit (often low airflow from a dirty filter), 8 is a weak flame-sense signal, and 9 is an igniter-circuit problem. On a Carrier board, count short then long flashes: 13 is a limit-circuit lockout, 14 is a hard ignition lockout, 31 is a pressure switch that did not close, 34 is ignition proving failure, and 26 is a rollout switch - which means inspect the heat exchanger before going further. We read the code, then chase the named part rather than swapping the whole ignition train.

Which no-heat checks are safe for me, and which need a pro?

Safe to do yourself: confirm the thermostat is set to heat and calling, check that the breaker for the furnace or air handler is on, replace a dirty filter (a clogged filter is a leading cause of the high-limit trips behind a Trane 4-flash or Carrier 13), and make sure supply registers are open. On a Mitsubishi heat pump, give it a few minutes - a slow steady green LED during a defrost cycle is normal and the unit will return to heat on its own. Past that, leave it to a tech: testing the igniter and flame sensor, metering the pressure switch and inducer, checking the reversing-valve solenoid, and verifying refrigerant charge all need tools and the code history. One firm rule - if a furnace throws a rollout code (Carrier 26) or repeatedly trips the high-limit, shut it off and call, because that points at a heat-exchanger or combustion problem, not a comfort annoyance.

What does a no-heat repair cost in Santa Clarita?

The flash code sets the lane. A thermostat, control-wiring, or communication fault that left a working system idle is the cheapest path, often inside a $95-$450 diagnostic-and-service visit. The common gas-furnace failures - igniter, flame sensor, pressure switch, or an inducer behind a 2/3/4 or 13/14/34 code - generally run $150-$700 installed depending on the part. A stuck reversing valve or a defrost-board fault on a heat pump lands around $300-$1,200, and a refrigerant leak behind a P8 or U7 is $225-$1,500 to find, seal, and recharge. If the diagnosis is a cracked heat exchanger, we stop and advise rather than quote a band, because at that point repair-or-replace and safety drive the decision, not a parts price.

Should I worry about a cracked heat exchanger?

If a furnace throws a rollout code (Carrier 26) or repeatedly trips the high-limit, the heat exchanger gets inspected - a cracked exchanger is a carbon-monoxide safety issue, not a comfort one, and we will tell you plainly if that is what we find. For heat-pump-side faults see heat pump repair; the older Newhall stock gets the most winter no-heat calls.

Common questions