delivered the opinion of the court.
The questions presented upon the trial for the consideration of the court and jury were, in substance, first, whether appellants had performed their contract, and second, if they had not performed it, whether appellee waived performance, accepted the furnace, and was therefore liable for the contract price' notwithstanding. Ho evidence was offered by appellee claiming damages as for a breach of the contract, but his sole contention was that he never accepted the furnace. Ho assignments of error except as to instructions are argued.
It is stated by counsel for appellant that the cause was tried twice in the Circuit Court, by a jury, the first trial resulting in a disagreement, and the second (in which, as has been stated, the evidence is strongly conflicting) in a verdict for the defendant. In such case it is important the jury should be accurately instructed. Chicago City Ry. v. Canevin, 72 Ill. App. 83, and cases cited.
The second instruction requested by the plaintiffs, above quoted, would be the law as applied to the facts presented by this record if it did not make their right of recovery depend upon the defendant rejecting the furnace both within and at the expiration of the thirty days’ trial provided in the contract. The word “and” following the word “ within ” should have been changed to “ nor,” and the instruction, thus modified, given, or something of a similar import. Ho instruction presenting plaintiffs’ side of the case was given, and while it jvas not error to refuse the *68plaintiffs’ second instruction as presented, we are inclined to the view that a different verdict might have been reached had some instruction been given to the jury presenting the plaintiffs’ theory of their case. This instruction would not, however, be proper in case the defendant introduced evidence of damage and sought to set off or recoup such damage, without a modification in that regard.
The plaintiffs’ first instruction merely'presents an abstract proposition of law, which is not a correct one, and even if it were correct, as no application of it is made to the facts of the case, it was not error to refuse it. It is not the law that a written contract can not be varied by subsequent transactions, or conversations, as is stated by this instruction.
The third instruction, given at the request of defendant, is not the law as applied to the contract here under consideration. It makes the right of plaintiffs’ recovery depend upon their proving by a preponderance of the evidence that the furnace, or, as it is called in the instruction, “ the smoke consumer, saved fuel, prevented smoke and increased.the efficiency of defendant’s boiler, and that it was satisfactory to the smoke inspector of the city of Chicago.” This was not the contract of plaintiffs, and is more than they were required to show in order to entitle them to a recovery. The undertaking of the plaintiffs was to furnish their smokeless furnace, complete, on a thirty days’ trial, and if it did not economize fuel, raise the efficiency of the boiler and prove satisfactory to the smoke inspector of the city, then that they would remove it without cost to the defendant and leave his boiler setting in first-class condition. Plaintiffs did not warrant or agree that the furnace should do these things, but only that they would remove it if it did not. Under the terms of the contract defendant could only require its removal if the furnace did not accomplish these things within or at the. expiration of the thirty days’ trial, and also might have accepted the furnace during or at the expiration of the thirty days’ trial, or after, although it should not have done either of the things which plaintiffs *69claimed for it, and relied upon his claim for damages for a breach of the contract. It was not a pre-requisite to plaintiffs’ right of recovery under the contract that they should prove by a preponderance of the evidence the matters required to be shown by the instruction. Underwood v. Wolf, 131 Ill. 425-35.
This contract being in writing, and not containing a warranty—only a guaranty to keep the furnace in good condition for one year, an oral warranty made at the same time or previously, can not be sho wn. 1 Beach on Mod. Law of Contracts, Sec. 269, and cases cited; Carleton v. Lombard, 25 N. Y. Sup. 570-4; Deming v. Foster, 42 N. H. 165; Whitmore v. South B. I. Co., 2 Allen, 52-8; Shepherd v. Gilroy, 46 Ia. 193.
There was evidence tending strongly to show that the defendant made no objection to the furnace during the thirty days’ trial of it, which was given; that he did, in fact, accept it, and made no objection to paying for the furnace until long after the expiration of the thirty days; also, that the furnace complied with the conditions mentioned in the contract. In the Underwood case, sufra,, the following language is quoted from Benjamin on Sales with approval, viz.:
“ The buyer will also lose his right of returning goods delivered to him under a warranty of quality, if he has shown by his conduct an acceptance of them, or if he has retained them a longer time than was reasonable fora trial.”
The court also states that in Owens v. Sturges, 67 Ill. 366, It was held that where the contract is unexecuted the buyer may retain the property and show the warranty and breach to reduce the recovery, even though he neglected to return the property upon discovery of the breach,” and after a somewhat extended reference to the decided cases, holds that an instruction for the plaintiff which, in substance, placed the burden of proof upon the defendants, who relied for a defense upon a breach of an express warranty, was proper. See, also, Morris v. Wibaux, 159 Ill. 627-43; Prairie Farmer Co. v. Taylor, 69 Ill. 440; Doane v.
*70Dunham, 65 Ill. 512; Mears v. Nichols, 41 Ill. 207; 28 Am. & Eng. Ency. Law, 776, and cases cited.
For the error in giving defendant’s third instruction, the judgment is reversed and the cause remanded. Reversed! and remanded.