Residential Service & Repair. Colby Plumbing is a small, locally owned company serving the Denver metro area. No job is too small or large for our master plumbers - kitchen disposals, water heaters, boilers, bathrooms - we are fast, friendly, efficient, and affordable. Our techs can swipe your card when the job is done, and we never charge a fee for using credit. We have thousands of satisfied customers - call us today!