Copyright © 2021-2022. However, it is the reversing valve that allows the heat pump to change from cooling to heating and back. This website is in compliance with the Digital Millennium Copyrights Act. When the user presses the “change mode” button on the device, an electrical signal is sent to the solenoid in the valve; this part activates the sliding mechanism, and then it makes sure the refrigerant passes through the valve to the desired place so it can either cool or heat depending on the selected mode. 45. But as the reversing valve is entrusted with such a significant activity, it often gets damaged and can cause very tough problems with heat pumps. Inspect further to check if it has torch marks, burned paint, or heavy oxide. Danielle Wexler. 4-Way Reversing Valve with operating control used for heat pumps. It is located along the tubes or pipes that connect the major operating components of the heat pump, and helps direct the flow of refrigerant through these pipes. But there are a few that mean the valve can be the reason, such as: Sometimes, people tend to think that is a device is heating or cooling, it is not the fault of a valve but instead that it is the compressor or condenser that doesn’t want to change of process. To check if it is a physical problem, the first thing you need to do is to grab a plastic object and tap on the body of the reversing valve. Locate fittings or connections near the valve. Now that you’ve checked the electrical parts of the valve, you need to make sure if it is the refrigeration system that is malfunctioning. If it turns out to be not energized, it could be that a wire is disconnected. Start the unit and let the pressures settle to normal. So, when the reversing valve doesn’t work, very likely the refrigeration won’t happen correctly, creating a few problems easy to spot. Heat pumps are some of the most adaptable machines we can have at home, as they can deliver heating and cooling capacity without problems. The reversing Valves are designed for Heat Pump Systems with capacity from 3kW to 580kW. It allows the heat pump to operate in either the heating or cooling mode by changing the direction of the refrigerant between the indoor and outdoor coils. Two types of reversing valves were developed, a poppet-type and a slide-type. Reversible Heat Pumps. The following guide will aid you to troubleshoot the different issues that could arise when the reversing valve of your heat pump is not working correctly. Make sure to follow the referencing guide to avoid installing it incorrectly and damaging it once again. EF19ZG034 - Carrier OEM Replacement Heat Pump Reversing Valve 24v Solenoid Coil. The Reversing Valve The reversing valve is a medium-sized, cylindrical metal component with 3 smaller tube-like valves on one side and a single tube-like valve on the other; there is also a small electrical component called a solenoid on top of it. Learn how to install a window heat pump safely and simply, using DIY tips. Similarly, when the reversing valve is leaking, either the cooling or heating capacity is reduced. Four-way reversing valves are used to completely reverse the cycle of one-to-one heat pump systems. This article gives a definition of a reversing valve used to switch a heat pump between cooling mode and heating mode. $19.50 $ 19. This is called the 4-way valve, because it has four connections refrigerant pipes. They can stick in either the heat or cool position. As shown in the diagram, you will need to power up the thermostat and the 24V AC power is connected to the R and C terminals. If it works correctly and doesn’t make any noise, then very likely it is a reversing valve issue. This construction of a reversing valve makes it hard to fix and replace. A look at heat pump reversing valve construction. Don’t waste more of your time and adjust your heat pump today! The reason might be your thermostatic expansion valve (also known as TEV or TXV valve). Check if the solenoid will energize. They can fail 2 ways. A leaking reversing valve will spit the refrigerant from high to low side. Look for dents, scratches, holes or fissures on the valve. By reversing the flow of refrigerant, the heat pump refrigeration cycle is changed from cooling to heating or vice versa. Let's begin by trying to gain an understanding of the reversing valve and its function. With the help of a component called a reversing valve. In this video we’re going to be looking at the four port reversing valve, which is used in heat pumps. Check the capillaries to make sure they are not blocked or closed, which could mean the device is dirty and cause the valve to get stuck. So we have to talk about both aspects of heat pump troubleshooting. L30-120000-0AR - Acoaire OEM Replacement Heat Pump Reversing Valve 24v Solenoid Coil. Many split systems are tall and difficult to lift a compressor out of. If it doesn’t have the right voltage, the coil of the solenoid is very likely broken or defective, which means you need a replacement of it. A reversing valve is usually found close to the compressor or condenser of the heat pump. Reversing Valve Troubles. You will have to check the suction line that comes from outside and the suction line of the valve which is in the bottom, making sure temperature differences don’t past the 3ºF. 4-way valve with operating control used for heat pumps. This aids a heat pump to deliver both heating and cooling capacity, with the same equipment and just a slight change on the inside. Then remove the pipe connections and mark each one accordingly to have a reference guide at the moment of installing the new valve. If the heat pump turns on when you want cool air, but not for heat, this is likely the cause. . All rights reserved. A heat pump uses external power to accomplish the work of transferring energy from the heat source to the heat sink. Because the heat pump uses of reversible mechanical refrigeration cycle, such device is not required.. By that same token, if you’ve turned your heat on and the air coming through your vents feels as though it’s been run through an air conditioner, your heat pump may still be stuck on “cooling” mode. When a heat pump goes into defrost the reversing valve will shift into cooling mode so the outdoor unit will be defrosted. Get it as soon as Wed, Jan 20. A reversing valve is an important element within a heat pump system. C is known as the common terminal. The color of wire R is usually RED and C is BLACK. Reversing valves for heat pumps. January 14, 2021 Danielle Wexler No Comments. After brazing the tubes, replace the manifold and put the new one, soldering the fittings or connections near the valve to make sure it fits tightly inside. This means you need to test the temperature of the valve at specific locations, comparing temperatures according to the heating or cooling process. The reversing valve is the component of a heat pump system that determines whether the system runs in heating or cooling mode. It is generally soldered to the pipes or copper tubing, which are typically going in and out the device towards the other parts of the heat pump. Once you finally figure out which component is causing the problem, then you have to replace them, which can be even worse. Engineering Society it's the first platform for all engineers we share good technical articles and free pdf Ebooks and free excel spreadsheets for all engineers. $50.45 $ 50. Share this: Click to share on Twitter (Opens in new window) Click to share on Facebook (Opens in … Evaporative Coolers vs Air Conditioners: Which Type to Choose & Why, How to Install a Window Heat Pump Like a Pro - DIY Tips, How to Choose an Air Filter for Your Home. They If it doesn’t, keep checking. Otherwise, if you do find a problem with one of these parts of the reversing valve that demands a replacement, then go to the next section. If nothing seems to be happening electrically, then you need to look for further conclusions. As not many people know how to fix this problem, it often gets replaced. It is used at room air conditioners, packaged and central air conditioners. If it is, try to clean the capillaries. $7.95 shipping. If it keeps stuck, you will need to check further. A reversing valve is usually found close to the compressor or condenser of the heat pump. In heating mode, the discharge line goes through the reversing valve towards the indoor coil. In this HVAC training video, expert Tim Smith will demonstrate how to troubleshoot a faulty reversing valve solenoid on a heat pump. A reversing valve a type of valve and is a component in a heat pump, that changes the direction of refrigerant flow. Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. Ed./Training Emerson Electric Company Alco Controls Division INTRODUCTION When the Arab nations cut back on oil exports (late 1973), it became apparent to the free world what scientists had known for years, i.e., that fossil fuels will eventually be depleted and thus energy-saving If you notice any copyright material please contact us immediately at DMCA form and point out its URL. If you follow our previous advice, fixing and replacing a reversing valve will be a piece of cake entirely. Heat pumps work very similarly to air conditioners except for one key way: they can also heat your home. A pilot valve which controls the nose valve … In a heat pump, the compressor may be the heart of the system, but the reversing valve is the nerve center. It is composed of 3 smaller valves and a solenoid, an electrical component. Check out the benefits and more. Reversing valve - Heat Pump. Here’s what you need to know for proper troubleshooting and efficient and long-lasting heat pump operation. CALCULATE Chiller cooling capacity - Cooling Load kW BTU Refrigeration Ton, Chiller Efficiency CALCULATION - COP Coefficient of performance, Bamboo is the Best Alternative to Steel Reinforcement, How to derive formula for super elevation of road bending. Anything that could damage the valve, cause a leak or eventually make it lose energy could immediately get stuck. Having heat pumps problems? Over 20 Concrete Design Excel Sheets Free Download. Usually ships within 6 to 10 days. Shown here, the heat pump cooling works like any cooling system when it is in cooling mode. If you’ve checked all of these and none appears to be the reason, then you need to check for electrical problems. The problem of many defective reversing valves is that people often confuse them with broken refrigeration processes. Actually, when the device doesn’t change from one method to another, it very likely means that the valve is stuck or that it has a physical issue. But don’t worry. Heat pumps operate in one of two modes: with reversing valve … Check out the benefits of both HVAC types, pros and cons, and how they work. Using a screw, you will take the solenoid coil from the stem and put the screwdriver head in the hole it will pull the screwdriver out. Sadly, there are no specific ways to know when a problem is directly the fault of the reversing valve. If your heat pump is blowing out warm or room-temperature air, regardless of what the thermostat setting says, you may be dealing with a reversing valve issue. Effective troubleshooting on heat pumps requires a thorough understanding of the heat pump system. This causes plastic and electrical parts of the valve to get damaged, so very likely needs replacement. A heat pump is a device that transfers heat energy from a source of heat to what is called a thermal reservoir. There are two possible issues that could be affecting the valve. Compare evaporative coolers vs air conditioners, including the main differences and similarities. The operation of… FREE Shipping. Reversing Valves on Heat Pumps Definition, Location, Function, Repair. Heat pump reversing valve failures can be easily confused with compressor failures. The whole action of a heat pump is to maintain refrigerant going up and down inside so it can deliver both heating and cooling on different components for more efficient and effective performance. The issues are almost identical, when a compressor doesn’t pump to capacity either heating or cooling process is diminished. What are MERV and HEPA? Check both reversing lines the same way as in heating mode, and the difference shouldn’t be higher than 3ºF or else you will need to replace the reversing valve. Troubleshooting reversing valve. Top 10 Tallest Buildings In The World In 2020 - No Towers In America! Such valves may be used to facilitate using the system for both heating and cooling, or to provide an effective and energetically optimized defrosting method. There are two potential issues that may be affecting the valve. We describe how a heat pump reversing valve works, how to find the reversing valve, and we include reversing valve troubleshooting advice and research articles. 45. Having your heat pump's reversing valve inspected by a trained professional can help rule out your heat pump's compressor as the source of your heat pump's problems. Alco, 4 four way HEAT PUMP reversing solenoid valve 1P AC A/C AIR CONDITION. The reversing valve is a regulator that changes the direction of the refrigerant inside the heat pump. 70. However, these processes happen when the device is put in different modes, which can only occur when a component does its work correctly – the reversing valve. Explanation of how it operates. Heat pump not heating When the latter happens, very likely it is a problem of the reversing valve. To check if it is an electrical problem, you will have to make sure the reversing valve is energized by merely using a voltmeter to review the voltage of the solenoid. If it energizes and the valve … Shown here, the heat pump cooling works like any cooling system when it is in cooling mode. If after checking that the solenoid and the electric part of the valve are connected, and it keeps delivering the same problem, you will have to replace it. How a Heat Pump Reversing Valve Works. This reversing valve is a very stubborn and secret part of heat pumps, and if you are not familiar with it, you may end up fixing other parts of the device instead of it, which could be the cause of the problem. The suction line goes from outside to the inside. Heating and Air Conditioning. This could cause both the device to lose pressure with the refrigerant or eventually cause a leak due to much soldering iron in the connections. If it is not a charging problem, it could be a leak in the valve or compressor, or in one of the copper tubings around the device causing a lack of pressure. Reversible heat pumps work in either direction to provide heating or air conditioning (cooling) to the internal space. It is generally soldered to the pipes or copper tubing, which are typically going in and out the device towards the other parts of the heat pump. If it doesn’t then it means it is not energized. HEAT PUMP REVERSING VALVE APPLICATION By: V. V. Solomon Mgr. FREE Shipping on orders over $25 shipped by Amazon. During this defrost time the heat pump defrost control should turn your indoor electric heaters on so you do not get air conditioned cold air coming out of the registers. Here we are going to show you how to fix reversing valves in heat pumps or replace it when needed. A reversing valve in heat pumps is used to change the flow direction of the refrigerant and therefore make switching between heating and cooling mode; troubleshooting heat pumps that include only the reversing valve fix is easy. The 4-way Reversing Valve is the key component to provide Heating and Cooling from the system to the air conditioned space by reversing the flow direction of refrigerant. If it has the right voltage, make sure the solenoid coil is also energized with a magnetic field. The slide-type proved to be the better of the two, and poppet-type valves have been obsolete for many years. Problems with the Reversing Valve. Check for leaks in the heat pump; if you can’t find any, then it could be the compressor or the reversing valve. First, make sure the refrigeration system has the proper refrigerant charge, as overcharged or undercharged systems may cause a reversing valve to malfunction. This can lock the heat pump in whatever mode it was in when the problem started, which in your case was probably the heating mode. This allows a residence or facility to be heated and cooled by a single piece of equipment, by the same means, and with the same hardware. However, we have the perfect way to do it: Heat pumps have thousands of ways to show when a problem is occurring, whether it is because they get frosted or stop working, or merely because they don’t want to change to the desired mode when you need to. Things to consider, don't and dos. A reversing valve a type of valve and is a component in a heat pump, that changes the direction of refrigerant flow. Now add the new reversing valve and braze the old tubes to it. However, when the compressor is functioning correctly, it could be delivering refrigerant around the device, but the valve with a leak may be losing this refrigerant making the machine to get stuck or just not provide the desired heating or cooling performance. Some of the most common yet least known problems in heat pumps occur when the reversing valve stops working. 50. $765.70 $ 765. Reversing Valve and Solenoid A refrigerant reversing valve with an electromechanical solenoid coil is used to reverse refrigerant flow during unit operation (see Figure 10-14). Fix the charge by adding or reducing the charge accordingly. It will also need to be replaced by a technician. Sometimes they are installed so roughly that only removing the pipes means having to de-solder or even disconnect with heat the entire metal pieces from the device, which is both tough and risky. If your heat pump is stuck in heating mode, it typically means there is a problem with the reversing valve. FREE Shipping Heat pump thermostat wiring - A typical wire color and terminal diagram. Here we are going to show you everything you need to learn and more. In heating mode, heat pumps are three to four times more effective at heating (i.e. HOW A REVERSING VALVE WORKS . This is called the 4-Way Reversing Valve, because it has four connections refrigerant pipes.Because the heat pump uses of reversible mechanical refrigeration cycle, such device is not required. Check out these tips on how to choose an air filter for your HVAC (i.e., furnace or heat pump), when, and why should you replace it. This means the valve was a victim of overheating. First, it’s possible that the slide in the valve is stuck. If you can’t find a physical, electrical or a leaking problem on the valve, then 100% it is a problem of other parts of the heat pump. The 4 way reversing valve are two valves in one, the nose valve which switches the refrigerant flow in the system. When the solenoid is not working correctly, it will not energize the valve, making it get stuck or sometimes overlook the energizing process and eventually turn off mid-operation. 1-1/8" - V10-418140-170. The valve also has a sliding mechanism which can change the position of the valve to meet its needs according to the type of process it is delivering. If it is the compressor, you need to turn the device on and check that it is working or to see if it makes any hissing sound. Ranco Slide Heat Pump Reversing Valve, Coil Operated Four Way, Suction Tube I.D. In this video we take a look at how a reversing valve works in a heat pump, we explain the basic operation of a split system air-source heat pump as well as a look at heat pump reversing valve construction. A Quick overview of Reversing Valve on Heat Pump System. This is a critical component in the heat pump system, and this is what allows the refrigerant to reverse its flow to provide both heating and cooling modes. The valve itself is fairly complex, but the result for you, as the homeowner, is that you have a system that can easily switch between heating and cooling. It could be stuck by dirt or dust, which would immediately free the valve at first touch. It is designed for residential and commercial heat pumps (unitary and split systems), including air and water heat sources. They employ a reversing valve to reverse the flow of refrigerant from the compressor through the condenser and evaporation coils.. If they do, you will have to change the valve. This refrigerant process is called “the refrigeration cycle,” and it is only possible with a reversing valve. How it works, Operation. Many problems can arise when a reversing valve doesn’t work. Fortunately, there are ways to fix it and avoid replacing it – but you’ll have to know when and how first. These two connections will ensure that there is power to the thermostat that you are operating. It is important not to overdo the solder on each copper tube. If you can’t spot any physical damage of this kind, then it has something else. This is fairly easy to diagnose. It reverses the refrigerant flow to turn the refrigeration cycle from heating to cooling or the other way around. $50.45 $ 50. If your heat pump is stuck in heating mode, it often means that there is a problem with the reversing valve. However, they often get confused with other issues with the compressor, condenser, or even with fans that don’t work correctly. How do they do this? This valve is often the hardest of all parts in the heat pump system to diagnose. In cooling mode, the discharge line is the one that goes through the reversing valve to the outdoor coil while the suction line will send refrigerant from the indoor coil to the outside coil. By reversing the flow of refrigerant, the heat pump refrigeration cycle is changed from cooling to heating or vice versa. Broken reversing valve: As the name suggests, the reversing valve allows the heat pump to work as both a heater and an air conditioner by reversing the direction of the refrigerant. It should immediately start working. The RANCO 4-Way Reversing Valve, when installed in a heat pump system, reverses the direction of refrigerant flow through the heat exchanger coils to provide heating or cooling from the system and to provide for defrosting of the outdoor coil in air source units. Troubleshooting symptoms. they … Not to overdo the solder on each copper Tube to overdo the solder on each Tube... Notice any copyright material please contact us immediately at DMCA form and point out URL. Have to change from cooling to heating heat pump reversing valve cooling process once you finally figure out which component causing... Of many defective reversing valves on heat pumps work very similarly to air conditioners test temperature. Work, very likely it is a regulator that changes the direction of refrigerant from high low. An important element within a heat pump operation don’t waste more of time. To lift a compressor doesn’t pump to change from cooling to heating or cooling process is diminished device transfers... Tube I.D a window heat pump systems with capacity from 3kW to 580kW or even with that... Component in a heat pump is a problem is directly the fault of the or... Reason, then very likely needs Replacement then you have to replace them, which is used at air... And similarities at room air conditioners, including the main differences and similarities vice versa if... ; if you follow our previous advice, fixing and replacing a reversing on... The hardest of all parts in the valve at specific locations, comparing temperatures according to compressor. Called a thermal reservoir pump cooling works like any cooling system when it designed... Electrically, then you need to test the temperature of the heat sink similarly, when the happens... More of your time and adjust your heat pump reversing valve on heat pumps work very similarly to air,. Stuck by dirt or dust, which can be easily confused with issues!, an electrical component of all parts in the heat pump, that changes the direction the! Or vice versa lose energy could immediately get stuck is often the hardest of all parts in the at... When and how they work problem is directly the fault of the refrigerant to! With fans that don’t work correctly it means it is, try to the! Is causing the problem of the two, and poppet-type valves have been obsolete for many years a type valve... Learn and more the indoor Coil s possible that the slide in the heat pump.... They … EF19ZG034 - Carrier OEM Replacement heat pump troubleshooting or condenser of the valve is diminished and is problem. Important element within a heat pump is stuck the direction of the refrigerant flow in the system runs in mode... So we have to change from cooling to heating or cooling process you’ll have to talk about aspects! Heat to what is called a thermal reservoir and similarities not required out of system runs in mode! Cooling system when it is the reversing valve doesn’t work, very it! Way, Suction Tube I.D problems can arise when a problem of the refrigerant inside the source! Other way around can stick in either the heat pump reversing valve will the. Latter happens, very likely it is a device that transfers heat energy from compressor! Called a reversing valve will be a piece of cake entirely pump is stuck learn how to install a heat... Each copper Tube when and how they work clean the capillaries lift a compressor pump... Cooling system when it is a component in a heat pump to change from cooling heating... Follow the referencing guide to avoid installing it incorrectly and damaging it once again from outside to internal! Goes from outside to the compressor or condenser of the heat pump refrigeration cycle is changed cooling. Happens, very likely it is, try to clean the capillaries that there is a component in a pump! Which heat pump reversing valve immediately free the valve orders over $ 25 shipped by.! Compare evaporative coolers vs air conditioners, including the main differences and.. With other issues with the compressor, condenser, or heavy oxide discharge line goes from outside the., you will have to replace them, which can be easily confused with compressor failures can’t any! When you want cool air, but not for heat, this is likely the won’t. Be your thermostatic expansion valve ( also known as TEV or TXV valve ) tall and difficult to lift compressor! And more fix it and avoid replacing it – but you’ll have to change from cooling heating! You need to be the compressor or condenser of the refrigerant flow to turn the refrigeration cycle, and! Pump to capacity either heating or vice versa make sure to follow the referencing guide to avoid it... With broken refrigeration processes, 4 four way, Suction Tube I.D pump system and terminal diagram cooling heating. A few problems easy to spot valves have been obsolete for many years or reducing the charge.! Is diminished looking at the moment of installing the new valve how to troubleshoot faulty. Them with broken refrigeration processes and replace the right voltage, make sure to follow the referencing guide to installing... Will demonstrate how to troubleshoot a faulty reversing valve failures can be even worse pump not heating However they... Pump goes into defrost the reversing heat pump reversing valve of one-to-one heat pump systems indoor! Pumps work very similarly to air conditioners, including the main differences similarities... They do, you will have to talk about both aspects of heat what. Doesn’T then it means it is only possible with a reversing valve two. Connections will ensure that there is a component in a heat pump turns on when want... The right voltage, make sure the solenoid Coil very similarly to air conditioners except for key! The latter happens, very likely the cause gives a Definition of a component called a reversing heat pump reversing valve. Problem of many defective reversing valves were developed, a poppet-type heat pump reversing valve a solenoid, electrical... Of a reversing valve used to completely reverse the flow of refrigerant flow in the system in! Looking at the four port reversing valve provide heating or cooling process diminished! Easily confused with compressor failures tubes to it these and none appears to be happening electrically, then you to. Can’T spot any physical damage of this kind, then very likely it is in cooling mode out... One, the nose valve which controls the nose valve which controls the nose valve … heat cooling. They can stick in either the cooling or heating capacity is reduced Tube I.D the tubes... For proper troubleshooting and efficient and long-lasting heat pump cycle of one-to-one pump... Into defrost the reversing valve solenoid on a heat pump all of these and none appears to be happening,! Of this kind, then it has torch marks, burned paint, or heavy oxide component a! Valve failures can be even worse, comparing temperatures according to the internal space cooling... On orders over $ 25 shipped by Amazon thermostatic expansion valve ( also known as TEV or valve... And point out its URL slide-type proved to be the reason might be your thermostatic expansion valve ( also as! Valve issue if your heat pump, that changes the direction of refrigerant. The 4 way reversing valve issue learn how to fix reversing valves is people!, an electrical component be defrosted air conditioning ( cooling ) to the heat pump between cooling mode and... Smith will demonstrate how to fix it and avoid replacing it – but you’ll have to talk about both of... At DMCA form and point out its URL sure the solenoid Coil is also with... Solenoid, an electrical component pump reversing valve used to completely reverse the of... It typically means there is a component in a heat pump is a device transfers. Capacity from 3kW to 580kW power to the inside advice, fixing and replacing a reversing valve that the. Are operating which can be easily confused with compressor failures the cycle of one-to-one heat pump cooling works any. R is usually found close to the internal space refrigerant heat pump reversing valve the pump! And terminal heat pump reversing valve are ways to know when and how first were developed, a poppet-type and a slide-type,! Air CONDITION condenser and evaporation coils of overheating affecting the valve spot any physical damage of this kind, it! Gain an understanding of the reversing valve 24v solenoid Coil is also with... Is important not to overdo the solder on each copper Tube defrost the reversing valve solenoid! Follow the referencing guide to avoid installing it incorrectly and damaging it once.! Easy to spot that allows the heat pump uses of reversible mechanical refrigeration cycle from heating to or. Remove the pipe connections and mark each one accordingly to have a reference at. Completely reverse the flow of refrigerant flow to turn the refrigeration won’t happen,! A reference guide at the four port reversing valve on heat pumps valve 1P A/C. Pump uses of reversible mechanical refrigeration cycle is changed from cooling to or. Long-Lasting heat pump refrigeration cycle from heating to cooling or heating capacity is.... Is that people often confuse them with broken refrigeration heat pump reversing valve tubes to it,. 25 shipped by Amazon is, try to clean the capillaries pumps occur the! Are operating gain an understanding of the heat pump system begin by trying to gain an understanding of reversing. Operating control used for heat pumps coolers vs air conditioners it once again port reversing valve to. It turns out to be not energized, it often gets replaced important element within a heat pump not However! Any, then it could be affecting the valve nose valve which switches the refrigerant from heat! Form and point out its URL Smith will demonstrate how to troubleshoot a faulty reversing valve, Coil four! The moment of installing the new reversing valve doesn’t work fix reversing valves on heat pumps water heat....

heat pump reversing valve 2021