35
Rev. 05/2020
CHAPTER 11
BLADDER ASSEMBLY
Principles
It is best not to have the system HTF, that is in the water jacket, exposed to the
atmosphere. This is because of system HTF loss through evaporation. When system
HTF is lost, it must be replenished or soon the water jacket would be empty. Not only is
replenishing lost system HTF a nuisance, it is also accelerating the corrosion process
throughout the total system, because adding fresh system HTF is also adding more
corrosion causing minerals.
Bladder
Principle of the Bladder
The HEATMOR™ is designed to be a semi-closed system.
The bladder is a reservoir that accepts the increased volume of HTF that results when the
HTF within the water jacket expands as it is heated.
Similarly, when the HTF within the water jacket cools
down, HTF is drawn out of the bladder.
Operation of the Bladder
The bladder has a capacity of approximately 8 gallons.
Normally, the bladder should have a small amount of
HTF in it at all times. As the furnace cycles, the amount
of HTF in the bladder will increase and decrease. If at
any time the furnace is requiring additional HTF it will
use the reserve HTF in the bladder before having to be
topped up.
Filling the Bladder with
HTF
1) Keep your bladder valve closed when filling your stove with HTF, but open at
all other times. Your bladder should have a small amount of HTF in it.
Maintenance / Result
To maintain your furnace bladder simply keep the bladder so that it has a small amount
of HTF in it, so the bladder continues to supply the water jacket with HTF. If the HTF level
does run low, the possibilities of HTF boiling and firebox warping are increased.
