How to Know if a Heat Pump Reversing Valve Is Bad

The heat pump is an incredibly versatile machine since it can perform both cooling and heating without a hitch. The device can perform these processes in several different modes, but they activate only if a crucial component is working correctly—the reversing valve. It's where heat pump problems typically occur, but most people aren't familiar with it. In this entry, we'll explain how to know if the reversing valve is malfunctioning.

How to troubleshoot for heat pump reversing valve problems

Two of the most common reasons for a malfunctioning heat pump are a faulty compressor or reversing valve. There's a quick way to pinpoint which component is at fault.

First, turn off the condensing motor. While the machine is running, let the head pressure reach 475 pounds or its maximum point, whichever comes first. Remember, the indoor motor is the condensing motor if the system is running in heating mode.

Then, shut down the system to turn off the fans and quiet the machine. Listen to the system and try to pick up on any anomalies. The raised pressure developed in the test should magnify the symptoms and make them easier to track down. If the reversing valve has been energized, it will need to be hot-wired before the test so that it doesn't de-energize when the machine is shut down.

At this stage, there might be a hissing sound from a hot gas bypass source. To determine which part is leaking, put one hand on the compressor suction line or drone as it reaches the compressor. The other hand should be on the suction line as it leaves the valve. One of the two ends will get hotter much faster.

If the compressor end starts heating up, it means that the compressor isn't working properly. Conversely, if the reversing valve gets hot sooner, the problem lies within the reversing valve.

However, if neither of the two elements gets hot, the most probable culprit is the compressor since the place where you're touching it has been dislocated from the gas source. By contrast, the spot where you're touching the valve is close to where the gas is leaking.

Therefore, if there's bleeding in the compressor, it won't be easily identified. But if it's the reversing valve that's leaking, there will be no doubt which component is broken.

Also, compressors can have a weak valve without having a hot-gas bypass. Thus, if the valve is fine, the compressor must be the issue.

Optimal air conditioning is indispensable

Taking the DIY route when detecting heat pump problems can be successful, but it is always better to have professionals do the work. Call a professional in your area for an in-depth assessment and effective solutions.

Modern Air Conditioning & Heating is a Boulder City-based HVAC company offering 15 years of experience in residential and commercial HVAC services for all makes and models. You can also call us directly at (702) 919-4365.