The HeaterTreater blend door repair kit is the optimal solution for a broken blend door on many vehicles. However, many vehicles have difficult-to-access plenum boxes, making our standard repair incompatible. The Core Regulator is a product designed to solve the broken blend door problem for virtually any vehicle. This is accomplished by bypassing the blend door and regulating the heat with a switch (which controls the flow of hot coolant from the engine to the heater core), thereby saving the $1000+ repair charge to install a new plenum box.
This is a product from HeaterTreater that can be used universally on most automobiles. There are multiple applications that are listed below. The kit provides an electronically controlled valve that allows you to turn the flow of coolant through the heater core on and off. This can be used for either temperature control or AC efficiency optimization. We are adding pictures and information on different vehicles and will offer rebates for information feedback.
We are in the business of providing replacement blend doors for multiple vehicles. Our repair method includes cutting into the plenum box and extracting the broken door and replacing it with one of our metal assemblies. This is the preferred repair method for most vehicles, however, we find that a lot of vehicles have limited or no access to the blend door without complete removal of the plenum box. This kit is applicable for vehicles that are difficult or impossible to repair without complete disassembly of the dash and can actually be used on any vehicle.
As shown in the computer animation, the temperature of the air flow is regulated by a combination of cutting the AC compressor on and with the new HeaterTreater valve, cutting the flow through the heater core on and off. For AC, the heater core is cut off and is a neutral element in the system. All air now flows through the heater core and can be cooled by cutting on the AC compressor or just ambient air on a pleasant day. For heat the AC compressor is cut off and the heater core is switched for hot radiator fluid to flow through the core and provide heat in the system.
All of the AC functions will operate with the same AC control panel and will operate just as before the HeaterTreater installation. You won’t have the ability to warm up the AC by moving the blend door and letting some air flow through the hot core to “warm” up the AC, but the system will regulate temperature by cutting the compressor off if the air is too cold. It’s actually inefficient to cool then warm air and it will be a gas saving method to run the AC.
The heat in the vehicle will be a little different control method. Generally the core will get to temperatures upwards of engine operating temperatures and most humans aren’t comfortable at 200 degrees F. We’ve all started out on a cold morning with full heat and find that we need to cut back once the engine reaches operating temperature. The temperature is cut back by moving the blend door and mixing hot air with ambient air to reach a comfortable temperature. Without the blend door operating, the temperature has to be controlled with the following methods:
• Cut the fan speed down to blow less air through the core and out of the vents.
• Set the air intake to outside air to bring in frigid air rather than re-circulate internal air.
• Cut the flow of fluid through the heater core off such that it cools down and doesn’t heat the air to full engine temperature. Cut it back on when it gets too cold.
• Last resort, roll the window down a little…
This is basically the way temperature was controlled in the 40’s and isn’t at all difficult, just takes a little knowledge of the system and more “human” control rather than “computer” control. Just tell yourself that you’re smarter than the computer anyway…
The disadvantage of this installation is that you don’t have the same level of automated control over temperature and there is a little learning curve to getting the right temperature. The advantages are:
• You are removing a source of heat from the passenger compartment, improving AC efficiency in the summer. It’s hard to measure the difference since AC temperature is dependent on engine temperature, fan speed, compressor on/off cycle, blend door position. We attempted to measure the AC operation difference, but in normal in-town driving the results were erratic. We ran another experiment at steady highway speeds with everything at steady state operating conditions and measured a 7 degree difference in cabin temperature with the HeaterTreater system installed. We can’t guarantee these results, but just taking heat out of the passenger compartment WILL help AC.
• This is a much cheaper repair than taking the vehicle to a mechanic and paying for the vehicle to be disassembled, replace with another plastic blend door, and putting it all back together, about 10hrs labor at going rates around $100/hr.
• You actually improve mileage and fuel economy slightly since you will run the AC compressor at a lower frequency when it doesn’t have to cool both you and eliminate the radiant heat from the heater core. Approximately 2-4% of engine cooling is through the heater core and radiant heat distributed into the passenger compartment. This heat now stays outside the cabin. It’s actually a “green” step for your vehicle.