Heatmor 400-4S, User Manual

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CHAPTER 12
WATER JACKET
Principles of the Water Jacket
Water within the water jacket absorbs heat produced in the firebox. The heated water is used to transfer
heat from the HEATMOR™ into the building needing heat. The water jacket and the firebox are one welded
component and can be replaced.
Maintenance
Keep the proper concentration of water treatment in the water.
Supply Line and Return Line Threaded Connectors
Principles
The HEATMOR™ furnace is designed to draw the supply (hot) water from the bottom of the water jacket. This
may seem irregular (people know hot water rises), but this method mixes the water in the water jacket better
and often extends pump life. The return (cooler) water connects to the, upper, rear spud of the HEATMOR™.
A circulator (pump) moves the water at approximately three to 10 gallons per minute, through both lines under
very little pressure (3 psi). Always attach a BRASS fitting into the STAINLESS STEEL spud to prevent
galvanic corrosion.
Relief Vent Pipe and Weighted Pop off Ball
Principles
The relief vent pipe is connected to the top of the water jacket. The
weighted pop off ball sits into the relief vent pipe, putting a pressure
restriction on the total water jacket. When the water within the water
jacket is heated it expands. Because of the restriction of the weighted
ball on the relief vent pipe, the water will expand into the bladder,
instead of out onto the roof. Any time there is a build up of more than
two to three psi, the weighted pop off ball will lift up and release the
pressure, maintaining a completely safe situation.
The weighted pop off ball should always be on the relief vent pipe during normal operation
of the HEATMOR™ furnace. DO NOT permanently obstruct the relief vent pipe. This could
cause water jacket or firebox damage if pressure builds.
Relief Vent Pipe and
Weighted Pop Off Ball