Blue Bird M380 2003, Owner'S Manual

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M380 Owner’s Manual__________________________Interior and Exterior Systems Operation – Heating Systems – 4-10
Rev. “F” 4-10-13
Causes of Scale
Tap water is the most typical source selected for boiler fill water. Water contains dissolved solids such
as magnesium and calcium which when heated becomes much less soluble and forms scale. Scale
comes out of solution in the largest amounts where the temperature is highest in the system (i.e., the
boiler heat exchanger). As the scale builds up, noise and cold spots develop since scales plug up
water channels and acts as an insulator that impedes proper heater transfer.
Acidity and Corrosion
Corrosion is the result of metal oxidizing (that is, metals reacting with oxygen-rich boiler fill water).
The acidity of any liquid (including water) is a good indicator of how much corrosion will actually take
place. As a rule of thumb, boiler fill water should have a pH greater than 7 and less than 10.5. The
key to preventing corrosion is to make sure that the heating system is free of leaks and there is no
need to replace it with fresh, oxygen rich boiler fill water. Corrosion inside a hydronic heating system
stops quite quickly as the fill water stabilizes and becomes oxygen-starved. The pH should be
measured at least annually.
Since most hydronic heating systems are comprised of different metals (e.g., iron, copper, etc.) and
since boiler fill water is an electrolyte (that is, it will conduct electrical current), electro-chemical
reactions (“galvanic” reactions) can take place. As the fill water stabilizes, however, it becomes a very
weak electrolyte, so galvanic corrosion rarely becomes a problem – as long as the system remains
leak-free.
Preventative Treatments
Corrosion and scale inhibitors are relatively inexpensive. Ideally, they should be applied, once only, at
the time of a new installation or whenever a system has been completely drained. Boiler water
treatment specialists almost unanimously agree that the prevention of leaks and the elimination of the
need for frequent boiler water make-up are top priorities for hydronic systems.
4-10.6.11 Water Filling Procedure
After your system has been completely installed, filled with straight water, purged of all air, and
operating for a period of time at normal operating temperatures, you should now double check all
connections for leaks. If no leaks are found, the system can be drained and filled with a 50/50 mixture
of antifreeze and water.
CAUTION: Where there is a chance of contamination of your domestic water when using a
heating system, use antifreeze specifically intended for hydronic heating systems. Inhibited
propylene glycol is recommended. Do not use automotive, ethylene glycol, or any undiluted or
petroleum based antifreeze as they can cause severe personal injury.
To fill the system use a separate self priming pressure pump with a hose on the suction side. Put the
hose into a 5 gallon container. Remove the systems hose from the outlet of the expansion tank, which
is feeding the systems circulating pump and attach it to the outlet of the self priming pressure pump.
Remove the hose from the inlet of the expansion tank and hang it into the 5 gallon container.
Make a final check to ensure all of the air vents and drains are closed. Pour a mixture of antifreeze
and water into the container and start the pump. As the mixture is pumped out, slowly add more
mixture keeping the level above the inlet of the suction hose until all air has been expelled and the
mixture starts coming out of the return hose hanging in the container. This flushes the system of any
debris and purges the lines of air. Continue to run the pump for about 15 minutes.
When no more air is being expelled, stop the pump and reconnect the lines to the expansion tank.
Top off the expansion tank with the mixture and turn on the system’s circulating pump with the
jumper, located on the main control board just right of the pump fuse, marked “Circ. Pump Override”.
When the jumper is on, the pump will run continuously and the bottom LED will be lit.