Jon was punctual and extremely polite he replaced the diverter valve on the first visit, serviced the boiler and explained how to set the timer, he was very knowledgable on my boiler i will be booking him next year for a service. Kurt did an amazing job! kind and considerate! Installation was speedy and professional. What pre-hire questions should be posed to a plumber? Our installation and service technicians are the best in the business factory and ongoing training prepares them for even.