By Gary Bunzer
What’s In There?
Dear RV Doctor:
While draining my black-water tank, if I close the drain valve suddenly before the tank is empty, I hear a clanking noise from inside the tank. It sounds like something is floating loose and hitting the tank wall when the flow is stopped. This may have started during the winter. The black tank contents may have frozen, but I’m not sure. At the time, I thought it was ice floating on the water, but it happened again this past summer. There have been no terrible problems associated with this, but I do worry that whatever is loose could settle over the drain hole and cause issues. Do you have any ideas?
Don Young
Amarillo, Texas
During the initial toilet drain installation, when the installers cut the hole into the top of the holding tank to install the fitting, it’s possible that the round, three-inch cutout piece fell into the tank. Either that, or at some point something flushed through the toilet into the tank and you’re not aware of it. Another possibility is that a fixture or fitting has come loose inside the tank, such as a spray nozzle attached to the tank through the sidewall (a flushing attachment).
I don’t think I’d worry about it unless a problem develops. Yes, there is a chance it could partially block the tank outlet, and if that happens, it will be necessary to remove all the outlet plumbing and perhaps the toilet to see what may be lodged in there. There’s also the chance it could simply flush itself out during a normal evacuation. If it were mine, I’d wait and see. If you’d feel better about it, you could have it investigated, but it wouldn’t be a simple process.
Battery Bank Configurations
Dear RV Doctor:
I own a 1987 Blue Bird Wanderlodge. It is configured with six golf cart batteries set up as three separate sets of two batteries producing 12 volts each. These make one large 12-volt battery bank that is used both for engine starting and for house loads. The generator has its own battery for starting. I have seen numerous articles about Type A motorhomes with separate batteries for the main engine starter and for the house loads. I currently experience the hassle of not being able to start the main engine when the battery bank is partially discharged. Do you think it would be worthwhile to have an expanded battery setup with a separate battery group for the engine and a separate battery group for the house? Have you written any articles on test discharges to determine the ampere-hour capacity of a battery bank, and, if so, where can I obtain them?
Del Hart
Escondido, California
I’m a firm believer in maintaining two separate battery banks, one for starting the motorhome engine and the other for supplying all the 12-volt needs of the house portion of the coach. For one, it eliminates your current problem of not having enough battery current to start the engine after running the components in the coach. I know that Blue Bird incorporated some different thinking back in those days, but with proper battery separation and enough capacity to recharge both banks, I feel this is the better way to go, though you could have a third bank just for the generator.
It all boils down to doing the math. No matter how large the battery banks are, the coach will need enough charging power (amp-hours) to keep them both charged.
It likely would take an experienced RV service tech to completely design a new dual-battery setup for you. Items you’ll need include a high-output, heavy-duty engine alternator; a properly sized dual-battery isolator or smart solenoid; and as many batteries as required to start the engine and to supply all the low voltage for lamps, fans, motors, and devices in the house portion of the RV.
As mentioned, you’ll also need a properly sized charging device that can charge both banks when shore (or generator) power is available. I’ve written extensively about the TrueCharge2 by Xantrex: (http://goo.gl/K6xSQS). For properly configuring 6-volt and 12-volt battery banks, refer to my article “The Balance of Power” (FMC, January 2012, page 46); it’s available by visiting FMCmagazine.com and clicking on the “Back Issues” tab.
For now, to properly size each bank, determine how many amp-hours are needed to start the engine, how many amp-hours are required to run everything inside the motorhome that you’ll use at the same time, and then add a 20 percent reserve factor. With a smart solenoid or isolator wired between the two banks and the alternator, a dual-output charger (triple-output in the case of the TrueCharge2), all the requisite circuit protection, properly sized conductors everywhere, and perhaps the addition of a solar array, you’ll be set for longer sessions of dry camping.
Most battery makers publish the amp-hour capacity for each of the batteries in their lineup. Look to Trojan, Interstate, Optima, Lifeline, etc. for their specific information. Determine if you want wet-cell, AGM, or lithium-ion batteries, each of which have their own pros and cons. Grab your wallet, find a knowledgeable service shop in your area, and make a call.
Furnace Heats Intermittently
Dear RV Doctor:
My wife and I traded in our Type C motorhome in early 2013 for a leftover 2011 Winnebago Vista Type A with about 600 miles on it (a result of moving it to shows, according to the dealer). It has a Suburban furnace. After we took delivery, we stayed in the motorhome that first night, a cold one in March. The propane tank was full, and we were connected to shore power at the campground when we went out for the evening. Upon our return, the motorhome was cold — well below the set point of the thermostat. I moved the thermostat switch to “off” and back to “heat” and heard the furnace start normally. I checked outside to make sure hot air was exiting and the vents were not obstructed. I awoke around 2:00 a.m. and the temperature in the motorhome again was lower than the set point. I cycled the switch, and the furnace came on again. This pattern repeated, so we took the motorhome back to our dealer, but they could find nothing wrong.
The unit functioned normally for the summer and into the fall as long as we did not put a significant load on the furnace. However, when we traveled to Indiana to visit our daughter, temperatures dropped into the single digits, and we really needed heat. Again, the furnace would function for a number of cycles after I moved the thermostat switch from “off” to “heat,” but after a few hours it quit, usually while we were sleeping. We were forced to get electric heaters to supplement the propane system.
We took the unit to a second Winnebago dealership, and they also could find nothing wrong. Since we want to visit our daughter again, and global warming has not yet progressed to the point where we can get along without the furnace, do you have any recommendations?
Tony Radice
Via email
As noted before in this column, using the furnace during the winter sometimes can be problematic. I am a bit surprised that neither service center nor Winnebago considered the rate of propane evaporation during winter use, since they experience very cold winters there at the factory. The importance of furnace cleanliness must also be considered. My “Furnace Maintenance” article (FMC, December 2015, page 48) provides some useful tips such as keeping the furnace clean, maintaining a surplus of battery power, and keeping the propane container as full as possible during the winter months to help combat container refrigeration. In some cases, it might be necessary to warm the propane tank and regulator with a tank heater blanket.