Tuesday, April 2, 2024


 In the mid-2000s Roadtrek started installing the Dometic  Cool Cat RV  air conditioner/heat pump.  This replaced what had been used previously which was basically a home air conditioner that had a built in thermostat and controls.  The Cool Cat uses an external thermostat and control panel which not only sets the temperature for the Cool Cat's air conditioner but also the Cool Cat's heat pump, as well as the temperature for the furnace in the Roadtrek as well. The initial panel used was analog. Later Roadtrek used an updated by Dometic digital control panel and thermostat. The panel is also the on and off switch for the air conditioner, heat pump, and furnace along with a fan only setting for the Cool Cat - plus a      Hi/Low  speed setting and an Auto/Fan setting. The Auto setting is what is used to enable the Cool Cat to turn off when the temperature that is set is reached and come on again when the temperature drops or increases - depending on using the A/C or the heat pump. 

The Cool Cat like most other air conditioners has a filter in the front of the unit to keep dust and debris from entering the unit with the air that is brought into it.   The filter is foam - mine, as it came from the factory is foam backed with a thin plastic grid that gives the filter some rigidity to remove and put back in.  Some may have this or just a foam filter - replaced by a previous owner of the Roadtrek if your Roadtrek is pre-owned.  Because of how the Cool Cat is installed in the Roadtrek removing the filter can be awkward due to the close proximity of the two cabinets at the ceiling that are on each side of the Cool Cat. The filter does not slide up and out - as many home A/C filters do - but slides out to the side. 

You DO NOT have to remove the front grill to remove or replace the filter in the Cool Cat. If you look at the photo above there is a screw on the outer side of each of the two end round vents on the top of the front of the Cool Cat. These are the screws that hold the front grill panel on.  There is no need to remove those screws. There is a much better way to take out the filter.

1. The first thing to do is OPEN the door on the ceiling cabinet on the passenger side. With this door open you will have a lot more room to move around when sliding out the filter. The filter is going to slide out of the left side.  

2. With the open cabinet door you can get your elbow inside the cabinet to get your fingers onto the edge of the filter through the open slot on that side of the front Cool Cat panel and grab the edge of the filter. 

3. Just slide the filter out toward the open cabinet.  It is flexible and you can flex it out of the slot and completely out. 

4. The filter can be washed or vacuumed clean. If you wash it set it out to completely dry. If you vacuum the filter be careful that it has not become brittle and will disintegrate with the suction of the vacuum nozzle.  There should be no dirt behind where the filter has been in the Cool Cat if the filter has been doing its job. 

5. If you decide the filter needs to be replaced, you can use any of the cut it to size filters sold for air conditioners. I suggest getting one of the foam filters with the plastic grid on the back as it will go in and out of the filter much easier than an all foam filter.  Use the current filter as a template to cut the new filter to size. 

6. When you are ready to put the filter back in, it is going to slide in through the same place it slid out of from the same side BUT there is something to be aware of when putting the filter back in. There is a flexible plastic "clip" that holds the filter in place when it is in the Cool Cat. This does not get in the way of removing the filter but it will stop the filter from sliding back in if you do not follow the next step.


7.  Look at the photo above on the left side, inside the grill. You will see the clip that I am referring to. As you see it here, it is in place with the filter clipped down by it. When you start to slide the filter through the slot it came out of (again the open cabinet door next to it makes it easier to maneuver. Put your finger into the vent where that plastic loop is and move the loop toward the front of the vent cover to open the path for the filter to slide in on. The filter is sliding on a groove on the bottom of the cover. Once the edge is past that point it should slide along with the clip down and in place  and you can let go of the loop - but if there is resistance or the filter you have is just foam with no backing - keep that loop up until the filter is slid to the right side of the Cool Cat and stops.  if you are still holding the clip up, let it go.

8. The filter is now in place and the Cool Cat is ready for use. 

I clean the filter when we dewinterize and have used a vacuum to do it. I take the filter out of the Roadtrek, put it down on a flat surface and with a vacuum hose with a soft brush nozzle vacuum the front and back of the filter. 

If you decide that you are going to take the front cover off to remove the filter. When you remove the two screws on the front, it is not just going to come off. There are tabs on the bottom of the cover that fit into slots that hold the cover on. Because the Cool Cat is so close to the ceiling you cannot just pull the cover off when the screws are removed. You have to carefully pull the top of the cover slightly toward you and once you clear right above the cover move the cover up so that the tabs come out of the slots on the bottom holding them in. 


Just for further information about the Cool Cat. The Cool Cat is a closed system. There is no way to recharge the refrigerant in the Cool Cat.  There is also no access to any of the mechanical parts of the Cool Cat from the front with the cover off. It is necessary to remove the Cool Cat from the Roadtrek to work on it. This is something not advisable to do yourself.  It may be possible for an A/C shop to cut a charging port into the coolant line for a way to recharge the A/C BUT this can only be done with the Cool Cat out of the Roadtrek and an RV shop would have to take it out for you to bring it to an A/C shop.  Reinstalling involves sealing certain places around the Cool Cat inside the the opening and where it sits on the pan behind. (per the Cool Cat installation manual). Also- The heat pump in the Cool Cat stops blowing hot or warm once the outside temperature approaches 40 degrees F.  If you put it on and the temps outside drop to near or below 40F - the Cool Cat blows COLD!  This can be a big surprise if going to sleep with the Cool Cat on at night and during the early morning ours the temp outside drops! 😦⛄