Heatmor 200 CSS - Chapter 11 Bladder Assembly; Bladder Function and Operation Principles; Bladder Filling and Maintenance

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CHAPTER 11
BLADDER ASSEMBLY
Principles
It is best not to have the system water, that is in the water jacket, exposed to the atmosphere. This is because
of system water loss through evaporation. When system water is lost, it must be replenished or soon the
water jacket would be empty. Not only is replenishing lost system water a nuisance, it is also accelerating
the corrosion process throughout the total system, because adding fresh system water is also adding more
corrosion causing minerals.
The challenge is to maintain an airtight system, while at the same time, allowing for the expansion and
contraction of system water as it warms and cools. This is accomplished in a HEATMOR™ design through the
use of a weighed pop off valve and a rubber bladder.
Bladder
Principle of the Bladder
The HEATMOR™ is designed to be a semi-closed system, with
a maximum of pressure buildup (3 psi).
The bladder is a reservoir that accepts the increased volume
of water that results when the water within the water jacket
expands as it is heated. Similarly, when the water within the
water jacket cools down, water is drawn out of the bladder.
Operation of the Bladder
The bladder has a capacity of approximately 8 gallons.
Normally, the bladder should be approximately ¾ full when the
water temperature is at the high water temperature set point.
As the furnace cycles, the water temperature drops 20 degrees
Fahrenheit, approximately one gallon of water will ow from the
bladder. If at any time the furnace is requiring additional water
it will use the reserve water in the bladder before having to be
topped up.
Filling the Bladder with Water
1) When the entire system is bled of air and the water jacket of the Heatmor is full of water (water
ows out onto the roof through the vent pipe), leave the water from the water source owing to
the HEATMOR™ at approximately half rate.
2) Place the weighted pop off ball back on the relief vent pipe.
3) Open the bladder gate valve and let the bladder ll half full. Check by feeling the bladder through the
bladder inspection port.
4) Turn off the water when the bladder is half full.
Maintenance / Result
To maintain your furnace bladder simply keep the bladder half full of water so the bladder continues to supply
the water jacket with water. If the water level does run low, the possibilities of water boiling and rebox warping
are increased.
Bladder