I'll start this part of the Tank Heater Installation with, I guess, a warning.
Whereas the forward tank heaters were relatively easy to install and insulate and the Control Panel installation for the tank heaters was actually relatively easy unless one counts the hundred plus feet of wire to pull and drop, the rear tank heaters (Fresh Water and Gray2) were more difficult. I anyone is planning to "do it yourself", I would suggest reading all the posts concerning "Installing Tank Heaters", plan your work well, and allow for at least double the amount of time you think it will take. This IS NOT a single weekend chore. On our Alpine, the factors that make this task more difficult include the black pipe propane gas line along one side of the underbelly and across the front of this area, the Fresh Water tank drain, the front axle and brakes, the heating duct work, and the electrical and water lines down the port side. If you combine the installation of insulation to this task, the Lippert slide rails present another challenge which is solved in this post.
The solid black pipe gas line, and heating ducts to some degree, define the requirement to "cowboy up" and cut the coroplast and reflective bubble wrap vapor seal. Several weeks ago, I got on Factory RV Surplus (
www.factoryrvsurplus.com) and ordered 20 feet (6.1m) of Underbelly Tape. As I planned this task, I realized I needed more underbelly repair tape, so I returned to the website and ordered an additional 50 feet (15.25m) of tape.
I removed the 5 screws holding the coroplast to the I-beam on the starboard side from immediately aft of the black gas pipe that supplies the furnace back to forward of the first axle. I gently pulled this coroplast down, shown my flashlight inside, and spotted the Gray2 and Fresh Water tanks. I removed the screws supporting the gas pipe and coroplast on the port side within my planned cut area. My plan was to remove a section of the coroplast basically aft of the Gray2 tank to immediately forward of the Fresh Water drain. I wanted to line up my cuts so at least one end coincided with a screw hole for the coroplast. I also wanted to cut across the same "groove" of the coroplast rather than across the accordion folds within the coroplast. After several checks and a couple of talks with myself, out came the box cutter! (May the RV gods forgive me!) I gently cut only the outside sheet of the coroplast across the whole underbelly, then followed that with cutting the rest of the way through while elevating the bubble wrap so it was not cut. Once the coroplast was cut through, I pulled it out from above the gas pipe. I then used a pair of shears to carefully cut the bubble wrap, avoiding the heating ducts and a bit of wiring, along the forward cut edge of the coroplast. This is the only cut I made on the bubble wrap. I just rolled up the freed section and looped it over the forward axle out of the way. At this point, my planned work sequence had been going nicely on schedule, and this would be the last instance of this happening.
Of course, the first task was to "admire" the tanks and place my hand where the heating pads would attach. Examining the Gray2 tank, my eyes strayed to look at the entangled mess of duct work that lay within my reach. (See post "Untangling the Heat Ducts" under Modifications and Upgrades.) The Gray2 tank was shallow – the bottom of this tank was about 6" (15cm) above the reflective bubble wrap and coroplast. (Gray2.jpg) The Fresh Water tank was a white translucent plastic with a large rounded bottom. Several items struck me about this tank! One, that tank is a 50 gallon (189.3 liters) tank. Initially I was surprised since the rating on the Alpine is 66 gallons (250 liters) of water. Thinking further, I realize that the 50 gallon Fresh Water, plus the 12 gallon (45.5 liters) hot water tank, plus about 4 gallons (15.2 liters) in the Pex piping is 66 gallons! Not really the "truth in advertising" I was expecting. Second, the drain point on the Fresh Water tank is not the lowest part of the tank. In fact, it is about 3" (7.5cm) above the bottom of the tank and on the port side! I could see water inside the tank, and if I placed the flashlight on the side of the tank, I could see sediment or maybe construction "powder" on the bottom of the tank. This quickly convinced me of two "to-dos" – yes, sterilize the fresh water system twice a year, and park on an incline with the port side downslope to drain the fresh water tank! Lastly, there was a R-7 sheet of unfaced insulation that stretched from right in back of the Fresh Water tank to under the Gray2 tank. (Fresh_Water_Tank.jpg).
My attention was then drawn to the port side of the underbelly and fresh water connections. When I first got the Alpine, there were kinks in the Fresh Water tank fill line where the fill line passed from the upper utility basement to the lower basement (underbelly). I fixed this problem by re-routing the Fresh Water fill line and supporting it within a 2" (5cm) PVC pipe. This PVC pipe was well away from the Lippert slide rail and allowed plenty of room for the fresh water fill line and vent line to pass above the slide rail. I fed an electrical fish tape down the side I-beam into the utility basement area adjacent to the storage basement. Previous I had stored the electrical wires in this area to eventually feed through and connect the rear tank heaters. I bundled together the three sets of wires for the tank heaters (120VAC Gray2 and Fresh, 12VDC Fresh) along with a two lines of RG-6 coax for later use (Sirius radio and possibly DirecTV). I pulled these lines into the underbelly area of the tanks and coiled them for future use.
I wiped down the bottom of the Gray2 tank near the drain outlet with an isopropyl alcohol wetted shop towel to make sure it was clean and free of any oil or grease residue. I held the tank heater pad up to the bottom to assess the location with the thermostat end near the valve. Then peeled back about 4" (10cm) of the two papers covering the adhesive. I held the still paper-covered end of the pad to the tank and pressed the exposed adhesive to the tank bottom. As mentioned earlier, one should NOT smooth or rub the tank heater pad on to the tank, rather press it directly down onto the tank. Once the adhesive gripped the tank, it was a simple matter to pull a little of the paper back and press the pad onto the tank until completed.
The Fresh Water tank was a little more involved. I had made the decision to place both a 12VDC and a 120VAC tank heater pads on the Fresh Water tank. By doing so, I could run the tank heater while traveling and also while plugged into a CG electrical service. Though UltraHeat does have a single pad that has both 12VDC and 120VAC heating elements, I opted to utilize two pads – one for 12VDC and one for 120VAC. In this manner, if it is very cold, I could run both pads at the same time, whereas if I used the dual pad, only one voltage may be run at only one time. I also thought if either heater quit working, I would only have to replace the one pad and still have the other working. The Fresh Water tank is wide enough so that at it's lowest point, which is below the drain plug, the two heater pads fit very nicely side by side. However, to do this application and to insulate the area aft of the Fresh Water tank, I realized that I had to remove another section of coroplast! So, I removed another 4' section of coroplast adjacent to the previous one – from just forward of the front axle to just forward of the rear axle. Again, I did not cut the reflective bubble wrap, rather just curled more of it up and stuck it behind the rear axle.
I cleaned the area of application with a shop towel wetted with isopropyl alcohol. I chose to apply the 120VAC heater pad in the forward position on the Fresh Water tank. I held the pad up to align it with the center line of the tank and lightly made two marks with a Sharpie marker. I peeled the paper cover back in the same manner as before, held the paper covered end up to the tank for alignment, and pressed the adhesive exposed end to the tank. Once the 120VAC pad was mounted, I went through the same procedure for the 12VDC heater pad. (FW_heater.jpg)
I retrieved the electrical wires I had previously curled and stowed to connect the heater pads to the Control Panel. I had labeled each of these lines as to which heater pad they were to connect. These connections were relatively easy with wire strippers and a crimp tool.
Ron
Linear Mode
