Arrived on site customer stated that they have no heat. Upon inspection found that the boiler is not firing. Contacted tech support and they stated that the control module and the blocked vent sensor has failed. Replaced sensor and control module and boiler is now operating as it should but found that the damper needs to be manually open indicating that the motor had failed. Replaced damper as well and everything now appears to be in working order and there appears to be no leaks at this time. Collected payment.