CAUTION
Probe and float type low water cutoff devices require annual inspection and maintenance.
4.CHECK OPERATING CONTROL on boiler equipped with tankless heaters. With burner off, draw hot water until burner starts, then turn off hot water and check burner shutdown.
5.CHECK RTC CONTROL - see the Test Section in the RTC Installation and Maintenance Manual.
K.BOILER AND SYSTEM CLEANING - STEAM BOILER
NOTICE
A qualified water treatment chemical specialist should be consulted for recommendations regarding appropriate chemical compounds and concentrations which are compatible with local environmental regulations.
WARNING
Chemicals used in treating boiler water are toxic and/or harmful. Always use protective clothing and equipment when working with/near chemicals. Contact local authorities to determine if treated boiler water can be discharged into local waste water system.
1.Oil, greases & sediments which accumulate in a new boiler and piping must be removed in order to prevent an unsteady water line and carry over of the water into the supply main above boiler.
Operate the boiler with steam in the entire system for a few days allowing the condensate to return to the boiler. If the condensate can temporarily be wasted, operate boiler only for the length of time it takes for condensate to run clear. If the latter cannot be achieved or if the condensate is returned to the boiler, boil out the boiler using the SURFACE BLOWOFF connection. See Figure 40a.
a.Drain boiler until water is just visible in gauge glass. Run temporarily 1½” pipe line from the surface blowoff connection to an open drain or some other location where hot water may be discharged safely. Do not install valve in this line.
b.Add an appropriate amount of recommended boilout compounds.
c.Start burner and operate sufficiently to boil the water without producing steam pressure. Boil for about 5 hours. Open boiler feed pipe
sufficiently to permit a steady trickle of water from the surface blowoff pipe. Continue this slow boiling and trickle of overflow for several hours until the water coming from the overflow is clear.
d. Stop burner and drain boiler in a manner and to a location that hot water can be discharged with safety.
e.Refill boiler to normal water line. If water in gauge glass does not appear to be clear, repeat steps (a. thru e.), and boil out the boiler for a longer time.
2.Low pressure steam boilers such as the Series
24 should be maintained with appropriate water treatment compounds. After cleaning process has been completed, add water treatment compounds as recommended by your local qualified water treatment company.
3.Remove temporary surface blowoff piping and replug tapping. Boil or bring water temperature to 180°F promptly in order to drive off the dissolved gases in the fresh water.
4.If unsteady water line, foaming or priming persist, install gate valve in Hartford Loop and drain valves in return main and at boiler and proceed as follows:
a.Connect hoses from drain cocks to floor drain. Close gate valve in Hartford Loop and open drain cock in return main. Fill boiler to normal water level, turn on burner and operate boiler at this water level for at least 30 minutes after the condensate begins to run hot, then turn off burner.
Close all radiator valves. Remove all supply main air valves and plug the openings in supply main.
b.Draw about 5 gallons of hot water from boiler into a container and dissolve into it appropriate amount of a recommended boilout compound. Remove surface blowoff plug and pour this solution into boiler, then reinstall plug.
c.Turn on burner and keep operating while feeding water to boiler slowly. This will raise water level in boiler slowly so that water will be boiling hot and will rise slowly into supply main and back through return main, flowing from drain hose
at about 180°F. Continue until water runs clear from drain hose for at least 30 minutes.
d.Stop feeding water to boiler but continue operating burner until excess water in boiler flows out through supply main and water lowers (by steaming) until it reaches normal level in boiler. Turn off burner. Drain boiler. Open all radiator valves. Reinstall all supply main air valves. Open gate valve in Hartford Loop.
e.When boiler has cooled down sufficiently (crown sheet of sections are not too hot to touch), close
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