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Save $ with Tank Heaters Answers before you buy FAQ      Easy to retrofit Ducted vs ultraheat

How to Select UltraHeat Tank Heaters for Your RV's Holding Tanks

All holding tanks mounted below the floor of a motorized or towable RV and Caravan can potentially freeze solid in cold weather. UltraHeat® Tank Heaters are designed to protect your RV's black, gray and freshwater holding tanks from freezing. This allows the RV owner to use their major conveniences like the shower, sinks and toilet. Selecting the correct UltraHeat® tank heaters for your holding tanks is simple.

1. Select heaters by the WAY YOU USE your RV.

If you are traveling in your RV, moving from place to place, not staying in one place for any extended period of time the recommended UltraHeat® tank heater is either.

Use a 13.5 VDC powered tank heater(s)
or use the COMBINATION - AM-M3600 heater (DC/AC) (This heater has two (2) separate heating elements that operate INDEPENDENT of each other)
**check DC power source availability and converter size before selecting DC heaters**

If you choose a dual voltage heater not only are you protected when parked but you are also protected during travel, eliminating the need to find a dump station for fear of freezing on the way to your next location.

If you are accessing power from a portable generator or you are plugged into shore power (campground plug) and your not concerned about freezing during travel. Most construction trailers and park model trailers will also require this heater because they do not use 12v converters.

Use a 120 Volt AC (VAC) powered tank heater(s)


2. Determine the size(s) of holding tank(s) that need protection.

  • Up to 25 Gallon (95 Liter) Capacity:
    • Use AM-M0900     13.5 VDC heater
  • Up to 40 Gallon (110 to 151 Liter) Capacity:
    • Use AM-M1200     13.5 VDC heater
    • Use AM-M4200     120 VAC heater
    • Use AM-M3600     Combination
  • 40 Gallon to 60 Gallon (151 to 227 Liter) Capacity
    • Use AM-M2400 13.5 VAC heater
    • Use AM-M4800 120 (vac) heater
    • AM-M3600 Duel Voltage Combination heater - 2 heaters required
  • Larger than 60 gallon (227 Liter) Capacity, refer to chart (link) in this section. (multiple heaters wired in parallel)

3. Determine the Number of HEATERS required per holding tank

  • Simply add the number required for each size of holding tank(s) pipes, and elbows, refer to the chart below ---or---
  • Use the CONFIGURATOR to compute your heater needs.

 

13.5 Volt DC Tank Heaters

Heaters are wired directly into the 13.5 Volt DC power system (converter) in an RV. Installed on a fused 13.5 VDC power circuit and operated with a toggle power switch, the 13.5 VDC tank heaters are easy to operate. Once installed, turn the power switch "ON" when the outside temperature approaches freezing and turn the power "OFF" when the outside temperature stays above freezing.

120 VAC (Household Current) Tank Heaters

UltraHeat heaters are equipped with a 15-foot (4.6m) power cord and a standard two-prong electrical plug. An appropriate extension cord and access to 110-120 Volt AC standard shore power or generator power is all that is required to power and operate. Unplug the power cord when the outside temperature stays above freezing.


    HEATER CHART

Tank Volume
in GALLONS (Liters)

(Minimum to Maximum)
#AM-M1200 #AM-M2400 #AM-M3600 #AM-M4200 #AM-M4800
   0 to 40 (151 Liters) 1 or 1 or 1
  41 to 60 (227 Liters) 1 or 2
or 1
  61 to 80 (303 Liters) 2 or 2 or 2
  81 to 100 (379 Liters) (1 plus 1) or 3 or (1 plus 1)
101 to 120 (454 Liters) 2 or 3 or 2
121 to 160 (606 Liters) (1 plus 2) or 4 or (1 plus 2)


DETERMINE TANK HOLDING CAPACITY (GALLONS)

Determine the fluid capacity of each holding tank mounted below the floor (gallons). Holding tank capacities are normally listed in your RV's owners manual, or in the specifications for your RV. The capacity of a holding tank can be calculated. Measure the length, width and average height of a holding tank in inches. Multiply the length, width and average height, in inches to find the volume in cubic inches. Now divide the volume in cubic inches by 231 cubic inches per gallon to find the capacity of your holding tank in gallons.

DETERMINE TANK HOLDING CAPACITY (LITERS)

Determine the fluid capacity of each holding tank mounted below the floor (liters). Holding tank capacities are normally listed in your RV's owners manual, or in the specifications for your RV. The capacity of a holding tank can be calculated. Measure the length, width and average height of a holding tank in centimeters. Multiply the length, width and average height, in centimeters to find the volume in cubic centimeters. Now multiply the volume in cubic centimeters by 1,000 to find the capacity of your holding tank in liters.