I contacted Mark Davie based on an internet search for this type of service. I was impressed first of all because, though he was in the middle of something when I called him, he called back when he said he would. He also showed up to do the estimate on time, and brought a portfolio of pictures of similar jobs he had completed in my area. During the estimate, he discussed potential problems with the way my furnace room was set up and how to address them and he also incorporated some ideas I had (i.e., to eliminate my hot water heater and use the boiler to heat the in-slab water and our household water, thus eliminating the need to cut another hole in the exterior wall). When Mark provided his estimate, he also provided numerous refernces, copies of all his qualification certificates, more examples of his work, etc.) I also had another estimate done by a larger company I had used before (and had been satisfied with). To be honest, their estimate was considerably lower (but without the details and references from satisfied customers). When I told Mark, he asked if he could see the estimate and when I showed it to him, he walked me through it and pointed out the differences in cost due to lower quality components, using plastic versus copper pipe, etc.). He did offer to pretty much match their estimate, but I chose to pay the extra money because I was comfortable that he was an honest person intent on doing the best possible job. Mark completed the work on time and on budget and while I was on vacation (i.e., I didn't check on his progress every day, nor was it necessary). In fact, because we decided (mutually) to go to a larger (and more expensive) holding tank when he was halfway through the job, Mark took care of reselling my fairly new hot water heater, which pretty much compensated me for the difference. When we arrived home from our vacation, the difference in my basement was awesome. It's now comfortable and we can use it to work out, watch movies, host overnight guests, etc., and no one is freezing. The furnace room has been transformed. The quality of the workmanship is awesome and Mark also rerouted (no charge) some ductwork to make it even easier to move around. I would recommend DHL Mechanical's services without reservation.