Arrived onsite for no hot water form indirect boiler and maintenance for one gas fired high efficiency boiler. Found boiler off due to low water pressure. Used fast fill valve to bring pressure to 19 psi. Turn on the thermostats up to heat and confirm operation of the boiler and each zone valve. Turned the boiler off and removed heat exchanger cover. Cleaned heat exchanger. Cleaned the flame sensor and igniters. Performed a visual inspection of all electrical and inspected all external water components such as the exp tank, fill valve, backflow preventer and the circulator pump. Clear condensate lines. Confirmed system is operating and heating properly at this time.