Our Certifications at WM J Kraus & Son We’re passionate about providing the Keokuk community with the best heating and cooling service around. To do so, we’ve gone through rigorous training to receive the industry certifications you see below. Learn more about our certifications here and give us a shout at 319-524-3714 to speak directly with our representatives. Better Business Bureau WM J Kraus & Son is a member of the Better Business Bureau, meaning we follow ethical business practices and disclose reliable information with our customers. We have a strong rating and are proud to be part of this organization.