Viessmann Vitodens 100-W Boilers

Viessmann Vitodens 100-W Boiler Overview

The Viessmann Vitodens 100-W is a gas-fired, wall-mounted condensing boiler. The Vitodens 100-W is Energy Star rated with an efficiency of 94.0% AFUE. It has a stainless steel heat exchanger, and a low-emission modulating stainless steel cylinder burner which is factory calibrated to eliminate field adjustments. The unit has built-in automatic frost protection and multiple venting options with vent length of up to 200 feet. Pipe connections are located at the bottom with serviceable components in the front, allowing for easy installation and maintenance. The Vitodens 100-W is suitable for altitudes of up to 10,000 feet.

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Consumer Reviews of Viessmann Vitodens 100-W


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #2 of 6 Viessmann Boiler
  • 28.57% of customers recommended

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Viessmann Vitodens 100-W Boiler Reviews

Showing 1-5 of 14 reviews

"Stay Away"

1.0 rating
Very Unsatisfied

New home construction, installed 4 years ago, nothing but problems ever since. Even with original installer and support from Heat Tech (Vieseman's authorized tech support team in Connecticut.) no one can make this system work properly. It overheats, it underheats, and then sometimes it downright breaks and requires expensive replacement parts. All the boilers have broken completely in the past two months. Very expensive repair bills and heating bills, when it overheats the house. We have radiant heat and forced air so part of the problem may be calibration between the two systems, but after four years you would think it would be dialed in by now, total frustration and Viessmann boilers are at the core of the problem.

Joel Tractenberg

Lakeville, CT

"Great heat, but intermittent domestic hot water"

1.0 rating
Very Unsatisfied

I heat a well insulated radiant heat floor but is a complete disappointment when it comes to hot water. It was installed this last fall and has never worked properly. When someone takes a shower or uses one of the faucets, it will stop supplying hot water suddenly. Obviously makes for a very bad experience in the shower. The heater has more than enough capacity for this small apartment. I am not happy at all. My installer has not been able to fix it.

Andy W

N. Yarmouth, ME

"Sounds like a jet plane"

3.0 rating

Installed a Veissman hot water boiler system in Oct'18 to replace our original boiler over 50+ years old. The contractor did a great job with the install but it sounds like a jet plane when it starts up! Is this normal? Our old system never sounded like this.



"This is a great replacement for an oil based boiler"

5.0 rating
Very Satisfied

We moved from an oil furnace to a propane furnace. The Viessman 100 was our choice due to the fact we were also installing a propane fueled generator (Generac) This unit is great. It keeps our home warm and also provides hot water. So no need for an electric hot water tank! Highly recommended, quiet, small and efficient!




1.0 rating
Very Unsatisfied

Costly to maintain shit product! Within 2 years of usage the repair and maintenance cost is equivalent to buying a 2 brand new ones. Viessman crap!


Other Vitodens 100-W Reviews

The Vitodens 100-W is considered an excellent boiler on online forums. A professional on states that Viessmann was the first to make a stainless steel heat exchanger and the Vitodens 100-W has the best heat exchanger of any boiler. A comparison between the Vitodens 100-W and a similar Peerless unit on found most people choosing the Vitodens 100-W, with many saying that they don’t compare and one member stating that it is like comparing a Volkswagen to a Cadillac.

Vitodens 100-W Warranty

The warranty for the Viessman Vitodens 100-W boiler is comprised of the following:

  • 2-year warranty on the enclosure, combustion chamber, burner, controls and other parts
  • Limited lifetime warranty on the pressure vessel of the boiler. The warranty is prorated after the tenth year

The warranty covers only the original owner at the original site of installation. Labor costs are not included in the warranty.

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