If you’ve never heard of the draft pressure switch for your gas furnace, you’re not alone. Modern gas furnaces are equipped with a myriad of safety switches to provide safe and smooth operation; the draft pressure switch is just one of these safety measures. It is critical for proper heating system operation to have correct internal air pressure and this switch is needed to help the system determine whether there is the correct level of air pressure. As with any of the components of your heating system, if you suspect there is a problem with your draft pressure switch, you’ll need help from a professional technician, but it is a good idea to have a basic understanding of what this switch can do.
How a Draft Pressure Switch Works
When the heating cycle begins, air is pulled into your combustion chamber through the draft inducer fan. The draft pressure switch is designed to sense any negative pressure created when the draft inducer fan starts up. If the venting and air pressure are incorrect, the switch will automatically shut down the ignition sequence.
The Types of Switch
The design of draft pressure switch used on your furnace depends on the furnace design itself, but the types of switches can typically be divided into three categories.
Single Stage: If you have a single stage conventional furnace, it will usually have a hose leading to the body of the draft inducer fan connected to the pressure switch.
Single Stage Condensing: If you have a single stage condensing furnace, the pressure switch will be connected to two hoses. One is needed to sense the draft inducer fan pressure, while the second senses the condensate collector box pressure.
Two Stage: If you have a two stage furnace, it is likely that you will have two pressure switches. This is because your furnace has two heat exchangers, requiring each exchanger to have its own switch.
Common Draft Pressure Switch Problems
Draft pressure switches tend to operate at 24 volts. This means that if the flow of electricity to the switch drops below this, the switch will not work. Draft pressure switches can also become stuck in the “open” position. This will mean that the ignition process is automatically shut down each time the furnace starts up. Fortunately, a professional technician has the experience to check your draft pressure switch and determine a faulty switch is the underlying issue causing your furnace issues. If the technician determines that the switch is causing furnace problems, it will need to be checked tohttp://aroundclock.com/contact see if a repair is possible or if the switch will need to be replaced. In most cases, the technician is likely to err on the side of caution and suggest a replacement, particularly if the problem is suspected to reoccur.
Your draft pressure switch is an important safety feature of your furnace. This type of switch is a delicate component, so it is always best to call in a professional HVAC specialist for any repairs.