I've installed over 30 of the Vitodens 100's and a few 200's (and viessman oil boilers) over the last 8 years. I have had very little installation issues or call back complaints. Recommend the low loss headers, and a quality air separator. Also check water quality and use cleaner/conditioners (authorized by Viessman) especially if this is a replacement. Setup or check combustion with quality certified equipment. Remember any product can have issues but many of my findings in the field come back to installation. Follow manufacturer recommendations and true of any brand, hire a company who has actually been to a class for the brand they are installing.

Had this boiler installed winter 2008 whilst building a very large extension to my property. Services new plumbed rads (8) and underfloor heating to new build and (12) old rads to existing along with heating my hot water. Never had any problems with the boiler (professionally installed, regularly serviced). My bills are very low in relation to the size of my property. No complaints only praise as its on 24/7 365.

Had this boiler installed for my self build and have been running it for over 5 years without a single issue. It's running hot water, radiators on one floor and under floor heating on two floors. Make sure it's installed by someone truly competent and of course keep it serviced. My bills are far lower but this is probably as much due to the new house construction as to the boiler.

Far superior than any other boiler, if you have a Viessmann installed by an accediated Viessmann installer you will be offered an extended warranty for ten years. I have had my current boiler for three years, my gas bill reduced considerably after I had it installed. It his boiler knocks the socks off my last boiler

Three years ago I moved into a house with a Veissman boiler and have had no trouble with it whatsoever. It's easy to use, good controls and everything's very logical. I had the boiler checked and serviced before the winter really started - the maintenance guy gave it a thorough going over and replaced something small which didn't cost very much. The boiler has worked well again over the winter, keeping the house warm. This is a great boiler - compact so it doesn't take up laods of space and it runs efficiently without any problems. All in all, I'm very impressed with this boiler and would recommend it to others who are considering ahving a new boiler installed.

Have had our Vitodens 100 for 2 years now and could not be happier with it. It runs so quietly it is remarkable. Very efficient, I reduced my heating costs to less than half what I paid to run my old oil fired boiler. Also should mention that the physical size of the Vitodens is very small, compact. I gained a whole new room when I got rid of the old boiler. To me, the only downside might be the initial cost - it is not cheap by any means. Wish I had added the DHW Combi unit at time of install, but am going to add it this year.

Running the 26kw model, being used in a family home now 4yrs , no services either it's quite ,smart looking and well built. Fit these and forget.

We've had this boiler for two years without a problem - although the wireless thermostat (standard version) is not the easiest to use or understand . The benefit of this boiler - closed system- is that everything is contained in the boiler itself- we had a pressure cylinder 'megaflow' installed recently for the loft conversion and the plumber was surprised that we didn't have an external pump etc that is usual with the Bosch systems, Everything was installed smoothly and the boiler works well over three floors. I also have to add that our heating bill came down 400 pounds a year in the first year and with the cheaper tariffs now it's 500 (we did have a 40 year old boiler (open system) before though!).

Vitodens 100-W 30kw I was a little sceptcal about this combination boiler after reading many poor reviews on this site, however this as been installed for 14 months and i'm very impressed with the efficiency of the boiler, helping drive my gas bill down to only £65 a month (3 bed semi) The boiler was installed onto a newly piped system a mixture of copper and plastic pipe. A scale inhibitor and Magnaclean filter was installed and the full system cleaned by a powerflush. The gas pipe had to be increased from 15mm to a mixture of 28mm reducing to 22mm. I have had absolutely no issues with the running or reliability of the unit. It is super quiet too, my son can hardly hear it working within the fitted unit in his bedroom, Hot water is always excellent and there is more than enough Ummph to run my bath & digital shower and other tap outlets. I think this boiler runs slightly cooler than my previously owned models (Ideal & Woc Bosch) so therefore is takes a little longer to get the house to temperature. We find the economy setting of 4 is ideal for Autumn and cold mornings but once winter hits the setting has to be increased to the absolute maximum to heat the house. All in all a great boiler andit has a full 5 year parts guarantee (if installed by a Veissmann approved installer) however it must be serviced yearly to qualify.Winner!

For sure it's the best boiler you can buy for still a good price,but not the cheapest.sandrine cazaux montreal quebec canada

I have to agree the v-100 is a good boiler and worth the money! I replaced a wood/electric boiler with a nat. gas v100 and have cut my heating costs by 50 per cent with no problems so far. If your considering having one installed find a good fitter that has had experience with this product and dont cheap out on the installation.

I've had a Vitodens 100 in my rental property for over seven years. It's never let me down. What more can I say it's a boiler and it works. By boiler prior was a baxi and lasted only two years.

I've had a Vitodens 100 in my rental property for over seven years. It's never let me down. What more can I say it's a boiler and it works. By boiler prior was a baxi and lasted only two years.

My boiler was installed just over 2 years ago. Apart from a error in the wiring up by the plumber the boiler has worked without fault. I think this comes down to the quality of the installation. The annual service is quiet expensive but keeps the 5 year warranty in place. My only complaint would be that I would like the display back lit.

During this cold winter I have further come to appreciate Scott Bivand's January 2009 installation of our Viessmann Vitodens 100 ultra high efficiency boiler that heats our home. Scott and his dad completed the installation in less than one day converting our 1870 house from oil to gas, arranged the removal of the old boiler and oil tank and left the basement cleaner than when they found it. Their plumbing job is a work of art on its own. They also installed a Bradford White on demand domestic water heater system at the same time. Small compact, high efficiency units - the extra space we gained in the basement was an added bonus - our heating bills plunged from about $1,500 a winter to about $600. Highly recommend Scott's AL+B Plumbing & Heating and the Viessman & Bradford White units. There were no hidden costs, all was as quoted. All has worked flawlessly. Of course Scott happens to be a boater - so its hardly surprising that he is a honourable fellow.

very quiet boiler,reliable, going to buy 2 more

I've been installing Veissmann boilers for two years now and they are by far the best on the market. I previously fitted worcester bosch, but have found Veissmanns are more reliable and better made. No other manufacturer gives a 10 year guarantee on the heat exchanger. buy one now !!!