Friday, February 1, 2013

IRS withdraws right of Shaver Furnaces to claim tax credit

In May 2010 the Alliance for Green Heat wrote to the IRS, urging them to look into the matter of unqualified outdoor wood boilers claiming to be 75% efficient. The Alliance had found one manufacturer, Shaver Furnaces, who had certified their unqualified boilers as 75% efficient lower heating value (LHV) allowing customers to claim what was then a $1,500 tax credit.

The inside of a Shaver
boiler.  For more.
Over a year later, the IRS issued a ruling, finding that Shaver Furnace “failed to meet the efficiencyrating of at least 75% as measured using a lower heating value.”  The IRS revoked the companies right to provide a certification on which future purchasers of the furnace can rely. The ruling did not impact the ability of Shaver consumers to take the tax credit prior to the date of the ruling, Nov. 28, 2011. It does not appear that the IRS imposed any fine on Shaver.

The Alliance for Green Heat is not aware of any other manufacturer who has been denied the right to claim 75% efficiency, but has been very critical of the industry practice that allows virtually every wood and pellet stove to claim 75% efficiency. In reality, wood stoves that claim 75% efficiency may be below 65% efficient LHV and some pellet stoves are under 60% LHV, with some even under 50%.

In February 2011, 8 months before the IRS ruling, Barrett Enterprises urged consumers to buy the clean burning traditional Shaver Furnace “before prices increase.”

Four days before the IRS ruling, Shaver Furnace put out a notice on its Facebook page saying “Shaver Furnace is proud to announce that the Shaver Pro Series 165, 250, 290 and 340 models have all been tested and certified to be 75% efficient or better and this allowed us to offer you a certificate to get the $300 Federal Tax Credit for 2011. Being eligible for the tax rebate means that your Shaver Furnace will burn less wood than with other manufacturers who don't qualify for the rebate and therefore you will use more wood with the other - being less than 75% efficient. That's proof, not just rhetoric.”

A chart of outdoor wood boilers, presumably made by Shaver Furnaces, listing which companies qualify for the IRS tax credit gave a green “yes” only to Shaver Furnaces. Other manufacturers, including Central Boiler, Heatmor and many others were all listed with a red “no.” The site said a red “no” designates “WORST or undesirable.”

Shaver Outdoor Furnace still claim to use “up to 25 to 50% less wood compared to other heating methods.” Their website says:

"Since the Shaver can burn larger pieces of wood it will dramatically reduce the time loading the furnace and the time spent cutting the wood - and there is no splitting. Plus the wood burns better and more completely. Costs for large round pieces are also significantly less than for shorter pieces of split wood..... Once the water heats up to the temperature you set it at, the fan goes off, allowing the fire to just smolder."


  1. "smolder" = insufficient oxygen for proper comubustion ... = <75% efficiency.

    This is the biggest "smoking gun" in OWB efficiency claims. ANY device that dampers the the combustion air is by design inefficienct in that it doesn't allow the wood to burn at the most appropriate rate. The only way to get the efficiency up is to burn the wood at the best burn rate and then bank the heat in some form of thermal mass (buffer tank, masonary blocks, etc) ... and then deliver the heat to the emitter as necessary to maintain the building at the desired comfort level.

    ... it's not magic, it's just math.

  2. I bought a shaver outdoor wood boiler based on the claim of being 75% efficient. After using it I quickly realized this was false. I was heating my house with an indoor wood stove. I using one face cord every two weeks. With the shaver boiler I go through a facecord every six days. Most of the energy goes up the chimney.

  3. Well... bought mine in 2008 and while it used a fair amount of wood, it did work. Eight years later I have a leak in the outdoor water jacket and Shaver seems to be out of business. So much for the " on site repair " and guarantee of 20 years.