State Industries SW 37-670 Manuel D’Utilisation

18

Lime scale should be removed from the elements by dissolving the 

accumulation  in  UN•LIME®  delimer.  UN•LIME  is  a  non-muriatic 

delimer,  available  through  your  dealer  or  distributor.  Do  not  use 

muratic or hydrochloric acid base deliming solutions to remove lime 

scale from the elements. Do not pour delimer into tank.

All models: 

1. Turn off electrical disconnect switch.

2. Drain the boiler following DRAINING instructions.

3. Remove the cabinet panel which covers the heating elements.

  •  Remove insulation as necessary to reach the element area.

4. Remove the bolts from each element and remove the elements 

from the opening.

  •  Disconnect element wiring as necessary.

  •  Use a twisting, pulling action to remove elements scaled  beyond 

the size of the tank opening.

  •  Brush loose scale from elements.

  •  Silicates, sulfates and aluminates must be removed by scraping or 

other mechanical means. Lime scale dissolvents will not remove 

these types of scale which are occasionally encountered.

5. Lime scale removal:

  •  Place  limed  ends  of  heating  elements  into  UN•LIME  delimer 

and allow scale to dissolve. Do not permit delimer or water to 

contact heating element electrical terminals.

6. Flush  cleaned  ends  of  elements  with  water  when  deliming  or 

cleaning is completed.

7. Remove  sediment  and  scale  from  the  tank  bottom  through  the 

tank cleanout.

  •  The make-up water valve and boiler drain valve may be opened 

to flush during the cleanout process.

8. Clean remaining gasket material from tank and element flanges. Do 

not reuse original element gasket. The element gasket is Part No. 

5109.

9. Replace elements as follows:

  •  Put a new gasket on each element.

  •  Install into tank opening.

  •  Uniformly tighten element bolts. Torque to approximately 32 ft /lbs.

10. Connect element wiring as necessary.

11. Follow FILLING instructions to restore boiler to service.

  •  Check for water leaks around elements and proper    

 

operation when boiler is filled.

  •  Replace insulation and cabinet panel.

Before  calling  for  service,  check  the  following  points  to  see  if  the 

cause  of  trouble  can  be  identified  and  corrected.  Reviewing  this 

checklist may eliminate the need of a service call and quickly restore 

the boiler to service. The illustration on page 5 identifies the location 

of most of the boiler components.

BE SURE TO TURN OFF THE ELECTRICITY WHEN CHECKING 

EQUIPMENT.

1. Be certain the electrical disconnect switch serving the boiler is in the 

ON position. The pilot switch(es) on the cabinet front should be on.

  •  In some installations the boiler electrical service may be limited 

by the power company or boiler controls. If the boiler operates 

on a controlled circuit heat may be effected.

2. Check the fuses.

  •  The electrical disconnect switch usually contains fuses.

  •  The boiler has fuses located behind the cabinet door, see page 

5 for location. 

3. If  the  water  was  excessively  hot,  and  is  now  cold,  the  high 

temperature  cutoff  may  have  operated  (manual  reset  equipped 

models).

  •  To reset, turn off electricity and remove the back panel and push 

the reset button.

  •  Repeated  operation  of  the  high  temperature  cutoff  should  be 

investigated by your servicer.

4. The capacity of the boiler may have been exceeded by a large 

demand for heat.

  •  Large  demands  require  a  recovery  period  to  restore  water 

temperature.

5. Sediment or lime scale may be affecting boiler operation. Refer to 

MAINTENANCE for details.

1. Refer to TEMPERATURE REGULATION.

1. Sediment or lime scale accumulation on the elements may cause 

sizzling and hissing noises when the boiler is operating.

  •  The sounds are normal , however, the tank bottom and elements 

should be cleaned. Refer to MAINTENANCE for details.

2. Some  of  the  electrical  components  of  the  boiler  make  sounds 

which are normal.

  •  Contactors will “click” or snap as the boiler starts and stops.

  •  Transformers and contactors often hum.

1. Check to see if the drain valve is tightly closed.

2. If the outlet of the relief valve is leaking it may represent:

  •  Excessive water pressure or air in the system.

  •  Faulty relief valve.

3. Examine  the  flange  area  of  the  elements  and  tank  cleanout  for 

gasket leakage.

  •  Tighten the bolts or, if necessary, follow the WATER AND LIME 

SCALE REMOVAL procedure to replace the gaskets.

Review SYSTEM CLEANING section, for a description of six problems 

which result from loss of system chemical stability. Chemical stability 

is checked by:

1. Draw off water from system. Is it dirty, discolored or odorous?

2. What is the pH of the system water? It should be neutral or slightly 

alkaline.

3. Does  “air”  purged  from  system  vents  burn?    If  so,  the  “air”  is 

actually gas.

If any of the above conditions are present, all waterways should be 

cleaned and the water adjusted to an alkaline condition.

1. Place the boiler electrical disconnect switch in the OFF position.

2. Close the make-up water inlet valve to the boiler.

3. Contact your servicer.