In May 1994, the Hubers rented a house to Lois Olbekson, who was the daughter of their friends, Loren and Alice May Olbekson. Lois hoped to be able to purchase the house from the Hubers one day. The primary source of heat for the rental house was a wood furnace located in the basement. Lois was not happy with the wood furnace. In the fall of 1995, she persuaded her parents to buy an oil furnace to replace the wood furnace in the rental house. During the process of installing the new oil furnace, the old wood furnace was removed from the rental house at the Olbeksons' direction and hauled to the landfill. Installation of the oil furnace required wiring in a thermostat and drilling a hole in the wall to accommodate the fuel line from the outside oil tank, and the Olbeksons had to widen an existing doorway into the basement in order to accommodate the new oil furnace. The Olbeksons paid $2,525 to have the new oil furnace installed. The Hubers acquiesced in the installation of the new furnace, but would not have done so if they had believed that they would be required to purchase it. During the time that Lois lived in the Hubers' rental house, the Hubers spent approximately $28,000 remodeling it, yet collected only $175 per month in rent. Lois admitted that before the remodeling was complete, the reasonable rental value of the house was probably $250 per month. In order to placate her husband about the rent, Emelia prepared an agreement that purported to tie the low rent to compensation for the cost of the furnace. The agreement, which Emelia and Lois signed, stated as follows: During October 1995, a fuel furnace for $2,525.00 was installed at 317 W. Lincoln and paid for by Loren and Alice May Olbekson. To compensate for the expense of this heating device, rent on this residence will remain at $175.00 per month thru the duration of Nov. 1st, 1995 thru Dec. 31st 1997. Lois continued to rent the house until September 2000. Even though the written agreement provided that Lois would enjoy reduced rent only until December 31, 1997, the Hubers did not raise the rent at any time prior to the termination of the tenancy.
At the end of Lois's tenancy, the Olbeksons removed the outside oil tank. Do they have the right to remove the oil furnace as well?