Jan 29, 2024 · Common Reasons For Furnaces Blowing Cold Air: 1. Your Furnace Isn’t Warmed Up Yet. That icy blast of cold air can stir up a sense of panic, particularly if temperatures are going to drop later in the day. If this is the first time you’re turning on your furnace for the season, make sure to wait several minutes. Malfunctioning Thermostat. A malfunctioning thermostat is one of the common culprits when your HVAC system blows cold air instead of heat. The thermostat …The furnace can blow cold air occasionally for various reasons, ranging from air leaks to short cycling and everything in between. The following are the seven most common causes and how to fix them. 1. Thermostat Issues. The first place to check when your furnace is blowing cold air is the thermostat.Monitor temperatures; if it’s -15°C (0°F) or lower, proceed. Before starting, plug in the block heater for 1-2 hours to warm up the engine. After block heater use, start the engine for smoother coolant flow. With the engine warm, touch the heater core lines. Both should be hot, indicating good flow.Shop for New Auto Parts at 1AAuto.com http://1aau.to/c/87/g/heater-coreDoes your car or truck not blow hot air from the heater vents, even after it's had tim...Winter is back, and it's colder than ever. Coupled with snow, dry air, sickness, and everything else that comes with winter, it's shaping up to be pretty rough. Here are 10 ways to... An electric heater that blows cold air could be caused by one or more of the following reasons: The manual reset has tripped. The fan switch is “on” and the thermostat setting is below the actual temperature. The fan is dispersing this air after shutdown. There may be a loose wire coming from the elements. The heater element may be defective. Heater blowing cold. Last week a bought myself a 2010 Zafira 1.7 ecoflex shes a lovely motor but has come with a couple of problems. First of all the fuel gauge is not working and F is displayed on the screen any ideas? there had been a short on the drivers dipped beam which had melted the plastic and I have repaired could this of shorted ...One of the most common and most reported problems with the Chevy Equinox 2006 model is that the heater blows out cold air. Other problems include the key not turning in the ignitio...Your furnace is supposed to heat your home, so the last thing you'd expect is to feel cold air coming from your home's air registers when your system is.Jul 22, 2023 · Reason #2: The Air Filter Is Dirty. This is one of the most common reasons a gas furnace will blow cold air and won’t shut off. Air filters get dirty and have to be replaced or cleaned on a regular basis. Your furnace has a safety switch, called a high limit switch, that opens and turns the burner off to prevent overheating or heat exchanger ... The heater may stop working in GMC Terrain due to low coolant level or air in the cooling system, clogged heater core, bad thermostat, faulty blend door actuator, bad water pump, dirty cabin air filter, bad blower motor, or HVAC control unit malfunction. 1. Low coolant or air in the cooling system. Low coolant level or air in the cooling system ...The heater may stop working in VW Jetta due to low coolant level or air in the cooling system, clogged heater core, bad thermostat, faulty blend door actuator, bad water pump, dirty cabin air filter, bad blower motor, or HVAC control unit malfunction. 1. Low coolant or air in the cooling system. Low coolant level or air in the cooling system ...90. Lexus Model: 99 LS400, 04 LS430 Ultra. Posted February 28, 2006. I think i may have my first problem at 135,000 miles. The heater is blowing cold air even when the car is completely warmed up. Before this problem, i would set the climate control at 72 degrees at start up and the hot air would start coming out the vents in small …One of the most common reasons for a Nissan car heater blowing cold air is a low coolant level. The heater in your car relies on the circulation of hot coolant ...Feb 20, 2020 ... 1. How to test Pressure Switch! https://youtu.be/pDc8prsNgJY 2. Blows COLD "MOST COMMON CAUSES" https://youtu.be/tcZZC0KQOvM 3.Dec 20, 2022 ... 2. Check the furnace's air filter. Your furnace may be blowing cold air because the filter is too dirty. A dirty air filter blocks airflow over ...If your furnace only blows cold air after you’ve turned on the heat, start your troubleshooting at the thermostat. Double-check that it’s set to “Heat” and “Auto,” not “On,” which may …Oct 1, 2020 ... Thanks for the pictures. That is a heat pump air handler. Heat is created from the outside condenser as well electric coils inside the air ...Feb 19, 2023 · Here are the steps that you should follow if your furnace is blowing cold air: Switch the thermostat setting. Check the control board diagnostic light. Change the air filter. Reset the high limit switch. Check the ignitor or pilot light. Clean the flame sensor. Check the gas supply and gas valve. A blocked heater core can also result in your Jeep’s heater blowing cold air. The heater core is a small radiator-like component responsible for warming the air that enters the cabin. Over time, mineral deposits and debris can accumulate within the heater core, obstructing the proper flow of coolant and reducing its heating capacity.Aug 12, 2022 · 6.7 Cummins Heater Blowing Cold Air . If you own a 6.7 Cummins and your heater is blowing cold air, there are a few things that could be the culprit. First, check to see if the engine coolant level is low. If it is, add more coolant until it reaches the full line on the reservoir. Next, check the thermostat to see if it’s stuck in the closed ... For example, with a natural gas furnace an issue with the supply line can cause the pilot light to keep going out. A propane furnace or oil furnace blowing cold air might indicate a low or empty fuel supply. And, a clogged oil filter can also cause an oil furnace to turn on and blow cold air.heater blows cold air A/C stopped working heater core engine complaint electrical issue heater complaint transmission complaint paint defect Rogue recall. The 2016 Nissan Rogue has 4 problems ...The heater may stop working in GMC Yukon due to low coolant level or air in the cooling system, clogged heater core, bad thermostat, faulty blend door actuator, bad water pump, dirty cabin air filter, bad blower motor, or HVAC control unit malfunction. 1. Low coolant or air in the cooling system. Low coolant level or air in the cooling system ...While a car heater blowing cold air can be attributed to a malfunctioning thermostat or coolant issues, a smelly car AC is usually caused by a build-up of mold, mildew, or bacteria in the air conditioning system. To address this, proper cleaning and disinfection of the AC system is necessary, along with replacing the cabin air filter if …heater blows cold air A/C stopped working heater core engine complaint electrical issue heater complaint transmission complaint paint defect Rogue recall. The 2016 Nissan Rogue has 4 problems ...Dec 21, 2020 ... 5 Reasons Why Heaters Blow Out Cold or Lukewarm Air · 1. The system is still getting warmed up. · 2. Your thermostat is set to the incorrect ...The heater may stop working in Chevy Equinox due to low coolant level or air in the cooling system, clogged heater core, bad thermostat, faulty blend door actuator, bad water pump, dirty cabin air filter, bad blower motor, or HVAC control unit malfunction. 1. Low coolant or air in the cooling system. Low coolant level or air in the cooling ...Dec 5, 2022 ... The Air Filter is Dirty. If your furnace easily overheats, that could be why you feel cold air being released. A safety device within your ...The air your furnace heats has to travel through cold ductwork, where it can lose a lot of heat along the way. Once your ductwork has warmed up, not as much heat will be transferred to it as air blows through it. At that point, the air coming out of your vents should start to feel warm. 2. Your thermostat is set to the incorrect setting.The heater core in the Chevy Astro van acts like a small radiator that the engine coolant passes through. If the van's heater has trouble working, you may need to replace the core....The heater may stop working in Honda CR-V due to low coolant level or air in the cooling system, clogged heater core, bad thermostat, faulty blend door actuator, bad water pump, dirty cabin air filter, bad blower motor, or HVAC control unit malfunction. 1. Low coolant or air in the cooling system. Low coolant level or air in the cooling system ...Goldfish fish only appear to be blowing bubbles as it opens its mouth to draw in water for oxygen absorption. Sometimes as the fish opens its mouth, air escapes and creates a pocke...Jul 9, 2023 · When your car heater consistently blows cold air during idle, it suggests a problem with the cooling system. Insufficient coolant flow due to a malfunctioning radiator fan, a clogged radiator, or a faulty water pump can disrupt heat transfer. Ask a professional to inspect your cooling system and rectify the underlying issue. 3. Reasons A Car Heater Is Blowing Cold Air. The most common reasons why a car heater is blowing cold air are due to a low coolant level, a malfunctioning thermostat, broken heater flaps, or air in the cooling system. It can also be caused by a clogged heater core or faulty heater controls. Here is a more detailed list of the common causes of why ...Dec 18, 2012 · Run the engine until it reaches normal operation temperature. Select the FLOOR position on the control assembly. Set the temperature control to full warm and the blower to the lowest setting. Using a suitable temperature measuring device, check the heater core inlet hose to see if it is hot. A lack of coolant and problems with the heater core are two of the most common causes of a heater blowing cold air. However, if you've checked these issues and ...Here is a guide that has a video showing you how to fix the problem: Make sure hot coolant is getting to the heater core by checking the heater hoses in the engine compartment. Make sure the blend doors and temperature controls in the heater box are functioning properly. Here are the diagrams to change the temperature air door motor (below).Mazda B3000: 2007 mazda b3000, heater only blows cold air only, 2007 mazda b3000, heater only blows cold air only, a/c works fine, no water leaks, I replaced thermostat. Also in vent position only cold air comes out when you turn temperature control. …If you have a heat pump, you will not use a wire in the W terminal. Move the W wire to the W2 or Aux terminal. (W controls your first stage of heating for Gas/Oil/Electric systems. O/B and Y control your first stage heating for heat pump systems. Backup heat sources must be connected to the W2, Aux, or E terminal for proper functionality.)Jan 25, 2023 · If your heater is blowing cold air, it can be a frustrating and in cold enough temperatures, potentially dangerous situation. Dealing with a broken heater in the winter can be stressful, but luckily there are steps you can take to stay warm. Keep your curtains and blinds closed to retain heat, and use extra blankets and layers to stay warm. Nissan Repair. This answer was rated: ★★★★★. Heater blow cold air only on driver's side. Passenger's side…. Answered in 5 minutes by: Nissan Mechanic: Jay. Hello, My name is***** been working on cars since 1990, I have been a Just Answer expert since 2008. Thank you for contacting us for assistance with your vehicle.Diesel Heater Fuel Pump Troubleshooting: Make sure there’s plenty of fuel in the fuel tank. Make sure the fuel tank hasn’t been mounted more than 2 metres below the height of the fuel pump. Make sure all of your connections are well-sealed, with no air getting in. Make sure the fuel filter and fuel pump aren’t clogged.Sep 25, 2018 ... Furnaces that run on oil have a filter that is like your car's which keeps contaminants like oil and dust out of the heating system. If the oil ...Malfunctioning Thermostat. A malfunctioning thermostat is one of the common culprits when your HVAC system blows cold air instead of heat. The thermostat …But if your car heater blows cold air and you’ve checked both heater core hoses to make sure they’re hot, you likely have a bum blend door actuator. You can usually diagnose and fix the problem yourself in about an hour. A new door actuator costs less than $100. All you need is a shop manual, a 1/4-in.-drive socket set and screwdrivers.Nov 10, 2023 · A truck heater blowing cold air could be due to several reasons, such as a malfunctioning thermostat, low coolant levels, air pockets in the cooling system, a faulty heater core, or a blocked heater valve. Professional inspection and troubleshooting are recommended to determine the specific cause and resolve the issue. Why is my truck’s heater […] GTyankee. 32816 posts · Joined 2009. #4 · Dec 29, 2016 (Edited) there is a chance that the heater core is blocked. one way to tell is to set your heater to all the high settings & drive a few miles. Then find the 2 heater hoses under the hood, both hoses should be hot or at least fairly warm.If you notice that your heater is blowing cold air, make sure to check the settings on your thermostat. Although it’s unlikely, you may have forgotten to move the …Learn why your heater is blowing cold air and how to fix it. Find common causes, specific issues for different heater types, and step-by-step solutions in this …If your Chrysler Sebring air conditioning unit is blowing warm air, the problem may be a small one that you can easily fix. By recharging the air conditioning with refrigerant, you...Heater blowing cold air. I hope someone may be able to help. The summer is over here in northern Europe and I just noticed that when I turn on the heater it is only blowing cold air. I have no idea how long this has been like this. I had two recent issues that may be related. First I had a notification to top up the coolant.Wrong Thermostat Settings. If you are wondering, “why is my heating unit blowing cold air?”, the first and somewhat obvious reason your furnace may be blowing cold air is …Heater blowing cold air. Now that the temps are falling, I am having issues with my climate control when in Auto. Recently, even though it was 35°-40° outside and the climate control was set to 74°, it blew cold air and the fresh air light was on. It did this for over 10 minutes. I kept raising the temperature, turned the Auto off then back ...Nov 13, 2013 ... The tech came back and said he just needed to adjust the new pressure switch. Apparently it was set such too tight and wouldn't stay closed even ...Oct 21, 2023 · A neglected filter can cause a furnace to blow cold air because it overheats and tries to cool itself by blowing cool air through the ducts and into the home. How to fix: Install a new filter, restart the system, and check the air from the vents. It will run cold at first because there is still cold air in the ducts, but the air should warm ... Nov 8, 2018 ... 7 Reasons Your Heater Blows Cold Air/AC Blows Hot Air · 1) Dead Batteries in Thermostat · 2) Clogged Air Filter · 3) Interrupted Startup ....Reason Four: The Unit Has Overheated. Your heater may blow cold air because it’s overheating, but this doesn’t mean that the unit is broken. When a furnace overheats, it causes the safety feature to shut the system off to prevent fires and carbon monoxide leaks. This means that your furnace is no longer heating, and your home is …A heater that blows cold air. Damaged Temperature Blend Door. The temperature blend door mixes the hot and cold air to give the right cabin temperature. Any damage to this door can cause severe heater control problems, such as: The heater blowing hot air when set to cold. The heater blowing cold air when set to hot. Inconsistent cabin temperature.Another possible cause of your space heater blowing cold air could be a broken thermostat. A thermostat controls the temperature your space heater generates. Essentially, a thermostat is a simple feedback loop. “A thermometer is something that measures the temperature; a thermostat is something that tries to maintain the …Nov 10, 2023 · A truck heater blowing cold air could be due to several reasons, such as a malfunctioning thermostat, low coolant levels, air pockets in the cooling system, a faulty heater core, or a blocked heater valve. Professional inspection and troubleshooting are recommended to determine the specific cause and resolve the issue. Why is my truck’s heater […] Nov 25, 2023 · The Role of AC in Heating. When it comes to your 6.7 Cummins heater blowing cold air, the air conditioning system plays a crucial role. The AC is responsible for producing both cold and hot air in your vehicle. If you find your heater only blowing cold air, then there might be an issue with your AC system. The air flow of the AC system is vital ... My car heater is blowing cold air on any temperature, unless I set it to 26 or above and it then blows really hot. I've checked the coolant resevoir and it's at the level it should. There is no leak in the heater matrix.Yet my fan heater is blowing cold air. I’ve listed this as the easiest to fix – but that’s only if you’ve mistakenly set it at a low level. Just turn it up! If the thermostat is actually broken then you’re not going to fix it. One indication is if you don’t hear it clicking on and off as you move the dial all the from end to end (when the appliance is plugged in …Check Furnace Air Filter. A second reason that your heater might be blowing cold air instead of warm air is due to a faulty furnace air filter. Furnaces fit with a clogged filter or dirty air filter can cause the heater to work overtime in order to compensate for the lack of indoor airflow and waste energy. To fix this issue, clean or replace ...Reasons for an Electric Furnace Blowing Cold Air. The Thermostat is Set to Fan or AC. The Thermostat is Bad. The Contactor is Bad – Coils Not Being Energized. One or More Coils are Burned Out. The Filter or Coils are Very Dirty. Circuit Controlling the Heating Coils is Tripped or Off.Your heater has to first collect and compress the air in your home, then heat it and expel the cold air. Heating systems work by heat exchange, which means that …1. It Hasn’t Warmed Up. If you just turned your heat on for the season or increased the temperature settings, your furnace will need time to adjust. Give it 10 to 15 …Feb 22, 2009 · As with many Tacoma PreRunner SR5 owners, my heater after 60K miles, and little use, only blows cold air. The coolant is at the appropriate level. The blower/fan works well, the vets all work well, the AC works well if activated but only stays on high. One of the most common reasons for a Nissan car heater blowing cold air is a low coolant level. The heater in your car relies on the circulation of hot coolant ...Another cause of your heater blowing cold air is a damaged water pump. A faulty pump can’t create enough pressure to circulate the coolant through the cooling system. Because of this, insufficient hot coolant reaches the heater core, causing the heater to blow cold air. 9. Blower Fan Issues. Next, issues with the blower fan can also be responsible …Learn how to troubleshoot common causes of furnace blowing cold air, such as thermostat settings, pilot light, gas supply, filter, and ductwork. Find out whe…Shop for New Auto Parts at 1AAuto.com http://1aau.to/c/87/g/heater-coreDoes your car or truck not blow hot air from the heater vents, even after it's had tim...Heater blowing cold air. Jump to Latest Follow ... I know when I'm blowing cold air and I switch the cold/hot know over to full heat, I can hear the little motor humming. Hope that helps. 2008 F250 Harley Davidson 4x4, Upgraded LED lighting, JL Audio 13.5" Stealthbox, JL Audio C3 door speakers, JL Audio 500.1 for the stealthbox, JL Audio …Jan 8, 2014 · 1) Turn on ignition, but do not start the car (foot off brake, press start twice - dashboard lights should be on) 2) Set both temp controls all the way up. 3) Hit "auto" on the climate control. 4) Turn fan control all the way down. 5) Press and hold gas pedal down for about 10 seconds. Oct 1, 2020 ... Thanks for the pictures. That is a heat pump air handler. Heat is created from the outside condenser as well electric coils inside the air ...If you have a heat pump, you will not use a wire in the W terminal. Move the W wire to the W2 or Aux terminal. (W controls your first stage of heating for Gas/Oil/Electric systems. O/B and Y control your first stage heating for heat pump systems. Backup heat sources must be connected to the W2, Aux, or E terminal for proper functionality.)pld118 Discussion starter. 9 posts · Joined 2020. #12 · Oct 23, 2021 (Edited) Solved - with enclosed “how to fix” YouTube video link. It was a coolant leak. Leaking from:-. Radiator Expansion Tank Hose Pipe: 2015 F56 BMW Mini Cooper 1.5D hatchback part number 17 12 7 617 366. £32 GBP from BMW main dealer.Also, if you have a mk1, there's a sneaky little trick you can do to check that the hot/cold air flap and its cable are intact. With the fans off, turn the heater control from min to max and back, feeling carefully how much resistance there is. Then, turn the fans to max, and repeat the same operation. If the is noticeably more resistance, then ...If you notice that your heater is blowing cold air, make sure to check the settings on your thermostat. Although it’s unlikely, you may have forgotten to move the …Thermostat Issues. The thermostat sends signals to your furnace to turn on …An electric heater that blows cold air could be caused by one or more of the following reasons: The manual reset has tripped. The fan switch is “on” and the thermostat setting …sebasteeno. 682 posts · Joined 2011. #3 · Feb 9, 2012. Very common fault as mines suffering with the same problem as are many others are too. Fixing is possible but the dealers will charge £2K as its a dash out job. Other fixes have been attempted with varying degrees of success but one i like the sound of is to cut open the heater box in ...It's free and it's worth a shot. Even though there are still technically a few more weeks of summer, the high temperatures and humidity haven’t gone away (at least in New York). An...The furnace can blow cold air occasionally for various reasons, ranging from air leaks to short cycling and everything in between. The following are the seven most common causes and how to fix them. 1. Thermostat Issues. The first place to check when your furnace is blowing cold air is the thermostat.The car heater can blow cold air because of different reasons. Most commonly, the car heater blows cold air because of the following reasons: Inappropriate working or a bad thermostat. Broken blower motor resistor. Insufficient supply of the coolant. Coolant leak.Also, if you have a mk1, there's a sneaky little trick you can do to check that the hot/cold air flap and its cable are intact. With the fans off, turn the heater control from min to max and back, feeling carefully how much resistance there is. Then, turn the fans to max, and repeat the same operation. If the is noticeably more resistance, then ...
With the engine at full operating temp, locate the 2 heater hoses where they go into the firewall and feel them to see if they are both hot to the touch. If they are. The temperature is controlled by the use of an air mix door that is operated by an electric motor/actuator. This door can be jammed or the actuator can be inoperative or have .... Hair salon pasadena
My car heater is blowing cold air on any temperature, unless I set it to 26 or above and it then blows really hot. I've checked the coolant resevoir and it's at the level it should. There is no leak in the heater matrix.whats up people !! Had a Problem with my Dodge Ram heat not getting hot. So this video i dig into the heater recirculation door and do a little hack to he...The car heater can blow cold air because of different reasons. Most commonly, the car heater blows cold air because of the following reasons: Inappropriate working or a bad thermostat. Broken blower motor resistor. Insufficient supply of the coolant. Coolant leak.1. Low coolant level - the cause more than you'd think on cars without rear heat. 2. Bad thermostat. However, the rear hear heat puts a kink in the thinking. Sounds like the coolant isn't making it to the front heater core which could be a bad heater switch or circuit to open the flow to the heater core. You may check the coolant hose going ...Just bought a used 2007 Chrysler 300, very very nice car. I noticed that when its hot outside the heater will blow out hot air even when the thermostat knob is off i have to turn on the AC to get it to stop blowing hot, but when its …A car heater blowing cold air is probably the worst thing to deal with on a cold winter morning. Here's how to troubleshoot this issue! Skip to content (800) 467-9769 Sales lines are open from 9am-9pm Central Mon-Sat. FREE SHIPPING ON KITS, SETS & BISON PERFORMANCE (800) 467-9769 ...1) Check the Thermostat Settings. It sounds simple but sometimes the most obvious fix is the correct one. Make sure your furnace isn’t set to “on” rather than “auto.” A thermostat set to “on” will continue …Dec 19, 2019 · 3 Reasons For Heater Blowing Cold Air In House. The thermostat’s fan is set to ON. Check the fan setting on your thermostat, and if it’s set to ON, switch to AUTO. That way, your blower won’t run 24/7 and thus send cold air through the vents if the room reaches the desired temp. The furnace air filter is dirty. A heater that blows cold air. Damaged Temperature Blend Door. The temperature blend door mixes the hot and cold air to give the right cabin temperature. Any damage to this door can cause severe heater control problems, such as: The heater blowing hot air when set to cold. The heater blowing cold air when set to hot. Inconsistent cabin temperature. Possible Conclusion 3: Your Heat Pump Is in Defrost Mode. Defrosting is another reason your heat pump might blow cold air through your vents. When your heat pump goes into defrost mode, it switches into cooling mode, causing the outdoor coils to heat up to melt any frost or ice within the system. However, because the system is in cooling mode ... The heater may stop working in Chevy Equinox due to low coolant level or air in the cooling system, clogged heater core, bad thermostat, faulty blend door actuator, bad water pump, dirty cabin air filter, bad blower motor, or HVAC control unit malfunction. 1. Low coolant or air in the cooling system. Low coolant level or air in the cooling ...Heater blowing cold air. Jump to Latest Follow 99K views 36 replies 14 participants last post by Jaybirdbronco Dec 23, 2017. W. wide body Discussion starter 255 posts · Joined 2011 Add to quote; Only show this user #1 · Dec 18, 2012. i've done some research on here regarding this issue ...Mar 1, 2019 · Many heater issues do require professional assistance, but you may be able to pinpoint the issue yourself to assist the technician. Here are a few troubleshooting strategies that you can use the next time your heater seems to be blowing cold air. Give It a Few Minutes. When you turn on your faucet, hot water doesn’t immediately come out. Check to see if your thermostat is set to ON or AUTO. If it is set to ON, your fan will constantly blow out air, even when your furnace isn’t heating it. Thankfully, this is an easy fix. Just turn the fan setting from ON to AUTO. Once you do that, your fan should only blow out air that is heated by your furnace.Feb 11, 2024 · Turn the power back on and test the heater. 3. Dirty Air Filter. The air filter in an electric heater helps to remove dust and debris from the air before it enters the heating system. If the air filter is dirty or clogged, it can restrict the flow of air and cause the heater to blow cold air. Mazda B3000: 2007 mazda b3000, heater only blows cold air only, 2007 mazda b3000, heater only blows cold air only, a/c works fine, no water leaks, I replaced thermostat. Also in vent position only cold air comes out when you turn temperature control. …Radiator heaters are commonly found in both older homes and new construction because they are energy-efficient and cost-effective. Expert Advice On Improving Your Home Videos Lates...Diesel Heater Fuel Pump Troubleshooting: Make sure there’s plenty of fuel in the fuel tank. Make sure the fuel tank hasn’t been mounted more than 2 metres below the height of the fuel pump. Make sure all of your connections are well-sealed, with no air getting in. Make sure the fuel filter and fuel pump aren’t clogged.If you have a heat pump, you will not use a wire in the W terminal. Move the W wire to the W2 or Aux terminal. (W controls your first stage of heating for Gas/Oil/Electric systems. O/B and Y control your first stage heating for heat pump systems. Backup heat sources must be connected to the W2, Aux, or E terminal for proper functionality.).