When your air conditioner starts losing cooling power without any obvious reason, the culprit could be something small but mighty: the liquid line solenoid valve.
This little component might not get much attention, but when it fails, it can secretly restrict refrigerant flow and cause a world of cooling trouble.
What Does The Solenoid Valve Do?
Think of the solenoid valve as a gatekeeper. It controls when refrigerant can flow through your AC system. When it’s working properly, the valve opens to let refrigerant pass freely to the evaporator coil, keeping your system efficient and your home cool.
But when it fails to open completely, it becomes a hidden flow restrictor, making your AC work much harder than it should.
How A Faulty Solenoid Valve Restricts Flow
Several things can cause the valve to malfunction –
- Incomplete Opening – Dirt, corrosion, or worn-out internal parts can stop the plunger or diaphragm from moving properly. Even when energized, it might stay partly closed choking refrigerant flow.
- Coil Failure – If the coil burns out or loses power, the valve may remain closed. In a “normally closed” setup, this means refrigerant can’t flow at all, disrupting cooling instantly.
- Blocked Pilot Hole – In some valves, a tiny pilot passage helps control pressure. If that hole gets blocked, the diaphragm can’t lift completely, creating a restriction.
- Internal Damage – Physical damage, like a bent spring or cracked part, can permanently jam the valve, reducing system efficiency and performance.
Signs Of Solenoid Valve Failure
If your AC is acting up, these are the telltale signs your solenoid valve could be to blame:
- Low suction pressure from reduced refrigerant flow.
- High superheat readings at the evaporator outlet.
- Normal or high subcooling, as refrigerant builds up before the restriction.
- Poor cooling performance throughout your home.
- Cold spots or frost on the line near the valve.
- Low compressor amperage, as it doesn’t have enough refrigerant to compress.
Preventing And Fixing The Issue
If you notice these symptoms, it’s time to call in an HVAC professional. A trained technician can measure the temperature and pressure across the system to pinpoint the issue.
Regular maintenance, like cleaning the system, checking for contaminants, and replacing worn parts, can prevent valve failures before they happen.
In areas like Loveland, Fort Collins, and Greeley, where hot summers push AC systems to their limits, having your system inspected annually is essential for consistent comfort.
Conclusion
A failed liquid line solenoid valve might be small, but its impact is big. Don’t wait until your system struggles to keep up; let the experts diagnose and fix the issue before it worsens.
For reliable local HVAC maintenance and repair, trust SWAN Plumbing, Heating & Air Conditioning, INC. We’re here to keep your Colorado home comfortable year-round.
