I did most of the research myself online and thought I had found a reputable company and a product that would match my home's needs. So I called Mr. Tankless and I went ahead with the purchase in relatively no time in late Aug 09. The Navien is perfect (so far - 2 weeks into the installation) with 15 years manufacture warranty. Unfortunately the specific installers, and from the looks of it Mr Tankless as whole, are DEEP in issues and past complaints. The installers were young, wearing jeans and what would easily pass as clubbing gear. I've purchased a furnace from another major contractor and the installers wore industrial overalls which implied that they took their job seriously and were prepared to do the job at hand, instead of the Mr. Tankless guy who was raising his low-rider jeans every 5 minutes to cover his butt crack. I asked them of their proficiencies and the main guy who was also the one guy who spoke English well enough to actually have a conversation said out front that he has a history of gas work but hardly any background in plumbing and actually "hates doing plumbing". He mentioned later that he was extremely tired and making mental mistakes because he was out until 4am the night before. Now I'm probably his age, possibly a year or 2 older and I can easily spot out a young go-getter who knows how to balance work and life, and I can also spot those my age who still don't appreciate having a job and don't take many things seriously enough. This guy and his partner fell very definitely in the later group. He also mentioned 1 or 2 stories of the harsher client complaints he had to deal with. They quickly assessed the layout of the laundry/furnace room and the exterior wall for venting. They vent this particular tankless system (and probably others) with 3-inch pipe. So you would expect that they have a 3-inch mortar bit handy. They in fact don't. They use a very much smaller bit and place multiple holes while blowing out the back end with every hole. The next day when there was enough daylight I inspected the outside wall (it's an 80 year old house and those walls are load bearing) I see 2 massive craters, see attached. A grenade could have made less damage. That's something I can live with, as I can repair the brick and mortar myself, and hopefully no structural damage will happen. The rest of the installation was sloppy, hardly any use of a measuring tape, no level as the venting and the tankless were all placed by eye, and the installers spoke their own language most of the time. I'm an immigrant myself, and I will speak in a foreign tongue in the presence of people who are familiar with it, but I will not do so in the presence of customers or anyone else who doesn't understand that language. It's a matter of respect to the customer to show that you are not concealing anything. The intake vent is recommended on being a rigid pipe, yet they opted to use a flexible metal duct for the intake. The installer wasn't too sure if it that was safe or if it caused any hazards. Part of the plumbing installation involves the use of flexible pipe. This type of pipe comes with its own tool kit so installers can install it correctly, see attached picture. The installers only had the crimper. They didn't have the expander, and the rest of the tool kit that would be used to make a more secure connection. They didn't measure the length of the pipe and the recirculation run (the length of pipe used to churn the hot water through the tankless for a second time) was just spread out through a ridiculous path across my laundry room ceiling and around the furnace. The part of the plumbing involving copper was extremely sloppy and extremely rushed and hurried. Remember the installer openly admitted early on that he has no plumbing background. He used a high temperature flame (possibly a MAPP) directly on the pipe regardless of the surroundings. He had the solder in front of the flame thus melting it before the fitting was heated instead of placing the solder behind the fitting to utilize capillary action. He could have possibly overheated the fittings. He didn't clean the fittings with a wet cloth to cool them off and remove excess flux, instead he actually rubbed more flux onto the steaming hot fittings and the flux quickly melted and fizzled. They also didn't come prepared with enough solder so they used some of mine that I had laying around. I wasn't there during the layout of the recirculation pipe. It didn't sit well with me once I saw it, and the next day after viewing the craters on the exterior walls from the drilling, as well as my doubt on the intake vent, I decided to call in about my concerns as well as asking for them to refit the recirculation pipe in a way that it doesn't take up such a large space (after all it is flexible and can be coiled). I work in a business environment, and I have a lot of experience dealing with people who are under pressure and/or not content with the status quo. So I also understand when someone is trying to deal effectively with those irked people and genuinely trying to resolve their situation. I asked to speak to someone with a technical background, and the person I spoke to came across like he has heard so many complaints that he was now indifferent to the whole thing. I told him about my concerns and he said he'll call me back that same day. He didn't call me back, so I called him at the end of the day in which time I'm sure he sent someone running to the bank to deposit my cheque that I handed to the installer so I couldn't back down. He actually forgot who I was and then said he completely forgot to call me back. To get to the point he offered his reassurance that the intake pipe can be flexible and that it doesn't affect the performance of the system. He seemed indifferent about the craters and said that they normally have a 3 inch mortar bit. He also promised to send a crew to do the minor and quick work involved with refitting the recirculation pipe. I told him to send a different crew; one that actually has the tools and the plumbing background to get the job done. Low and behold he sent the same crew, dressed in clubbing gear. They got the job done in no time. I thanked them and deep down I hoped that I never have any issues with my tankless so I never have to deal with that company again.