How much does a relay switch cost for a furnace?

Asked By: Benedetta Mosert | Last Updated: 27th May, 2020
Category: home and garden indoor environmental quality
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Relay or High Limit Switch Costs
Relay switches cost $150 to $300 to replace. They might cost $5 to $20 for the part alone with the rest in labor for the trip, diagnosis and replacement.

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Consequently, what is a relay switch on a furnace?

The electric relay in a furnace is responsible for relaying electrical power to the heating elements and the blower motor inside the furnace cabinet. The heating elements provide the heat to warm the air, and the blower motor sends this warmed air through the ductwork.

One may also ask, how do I know if my limit switch is bad? The most common sign of a malfunctioning limit switch is the continuous operation of your furnace's blower. Just as the limit switch won't allow the fan to turn on until the warm air has reached the right temperature, the limit switch also shuts down when the air cools to a certain temperature.

Also to know is, how much does it cost to get your furnace serviced?

Expect to spend anywhere from about $80 to $100 for a furnace tune-up, but more if repairs are also needed. Many companies offer service contracts or maintenance plans, which may reduce the cost of an annual visit from a pro and provide other benefits.

What is a limit switch on a furnace?

A limit switch is a device that's located under your furnace's supply plenum. A limit switch also acts as a safety device for your furnace. If the temperature inside of the plenum gets too hot, it shuts off the gas supply to your burners to prevent your furnace and heat exchanger from overheating.

35 Related Question Answers Found

What is a relay in HVAC?

A relay is just a remotely controlled switch that opens and closes using an electromagnet. Relay coils can come in many different voltages depending on the application, but in residential and light commercial HVAC 24-volt coils are the most common.

What causes furnace circuit board failure?

If the starting capacitor is failing, it can cause problems with your system. Replacing the capacitor is an inexpensive fix to solve the problem. A blower motor that is failing can also blow a fuse. It cause strain against the motor and draw too much power, which causes the system to short.

Where is fan limit switch on furnace?

Your fan limit switch is located inside the furnace panel cover, usually near the upper right corner. The fan limit switch is responsible for turning the blower on and off at the appropriate times.

What does a relay do on a boiler?

The relay on a boiler is the part of the boiler system which triggers the boiler to release heat when the thermostat calls for it. The thermostat is a device which measures the temperature of an area, and when the area gets too cold, it will send a message to the relay switch to release heat from the boiler.

What does a sequencer do in HVAC?


An HVAC sequencer is a small circuit designed to help stabilize circuits and turn switches on and off quickly in an electrical setting. The sequencers are designed to stage the different parts of the electrical equipment so that the appliance does not over load and break the circuits.

Can you clean your own furnace?

Clean furnace surfaces.
Wipe exterior surfaces with a damp rag. Remove the furnace access door by lifting it up and out. Loosen screws, removing the burner cover (if you have one). Vacuum the burners and furnace base using a shop vac or household vacuum with wand/upholstery attachment.

What is done during a furnace tune up?

The most important items on the furnace tune-up checklist include: Cleaning — The outdoor unit, blower, fan blades, and drain line all tend to get dirty and dusty over time. Testing — Gas and oil furnaces need regular maintenance because of the potential dangers of leaks and fumes.

How long does a furnace last?

Average Furnace Lifespan
While some furnaces can last over 40 years (extremely rare), the average lifespan of a typical gas furnace is around 15-30 years. As long as you have scheduled yearly furnace maintenance, your furnace should easily last over 15 years.

How much does an oil burner tune up cost?


A boiler tune-up costs $400 to $500 while repairs cost $150 to $1,000 or more. Boiler tune-ups catch minor problems before they become major issues. Regular maintenance and cleaning, often called a tune-up, keep your boiler running efficiently and inspects for any potential issues.

How do I tune up my furnace?

12 'Must-Dos' on a Furnace Clean and Tune
  1. Check the igniter by using an ohmmeter.
  2. Check the flame sensor (if present).
  3. Pull and clean the burners.
  4. Inspect the heat exchanger for excessive rust, cracks, or holes.
  5. On condensing 90%+ furnaces, blow out the condensate line.
  6. Check the system static pressure.
  7. Perform a combustion analysis.

How often should you have your gas furnace serviced?

A gas furnace should be serviced at least once a year, preferably, though, in both the spring and the fall. Annual maintenance, including a thorough examination and cleaning of the parts that commonly malfunction, like the air filter, the fan, the pilot light, and the heat exchanger, can usually prevent these problems.

How much is a blower motor for a furnace?

How much does a furnace motor replacement cost? On average nationwide, a furnace blower motor replacement costs $400-$600, including parts and labor. A single-speed blower motor costs around $450 to replace while a variable-speed motor costs $600+.

Can you reset a limit switch?


Consult your instruction manual before resetting your furnace's limit switch. The function of your furnace limit switch is to tell the fan when to turn off and on depending on the temperature in the home. It's possible to reset the switch at home when necessary by following a few simple steps.

How much does it cost to replace a limit switch?

Relay or High Limit Switch Costs
Relay switches cost $150 to $300 to replace. They might cost $5 to $20 for the part alone with the rest in labor for the trip, diagnosis and replacement.

What causes a high limit switch to trip?

When a high limit switch gets tripped due to overheating, that contributes to wearing out the switch faster. One of the most common causes of furnace overheating is a clogged furnace filter.