Heatmor 200X - Bladder Assembly: Principles and Operation; Bladder Function and Filling Procedure; Bladder Maintenance and Water Level

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BLADDER ASSEMBLY
Principles
It is best not to have the system water that is in the water jacket, exposed to the atmo-
sphere. 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 replenish-
ing 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 accom-
plished in a HEATMOR™ design through the use of a pop-off ball (if equipped), gate valve,
and a rubber bladder.
Bladder
Principle of the Bladder
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
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 six 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 off.
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 pop-off ball (if equipped) back on the relief vent pipe.
3. Open the bladder gate valve and let the bladder ll half full. Check by feeling the blad-
der 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 possibili-
ties of water boiling and rebox warping are increased.
Chapter 10
Bladder Tube