A different company installed a new boiler, and it never worked. That company couldn't figure it out, and eventually stopped trying. Christian at GTA never gave up until he was able to get it working (over two winters, he stuck with us.) He charged us reasonably, went out of his way to get us parts through the warranty, always returned my calls promptly and showed up when he said he would. his work is top notch. besides solving our heat mystery he put in a new fantastic system in the basement, which all other companies said was not possible. we recommend him without any hesitation.