Aqua Products manual Flow Rates Model Pipe Size MIN.GPM MAX.GPM, Connections, Inlet/Outletheader

Plumbing from the heater back to the pool must not have any valves or restriction that could prevent flow when the pump is operating.

CAUTION: A source of additional heated water, i.e. solar systems, must be connected to the heater outlet pipe. If this is connected to the heater inlet, incorrect pool water temperature readings will be displayed on the heater control panel.

Heater must be located so that any water leaks will not damage the structure of adjacent area. PVC pipe may be glued directly into header unions.

FLOW RATES

MODEL	PIPE SIZE	MIN.GPM	*MAX.GPM
185	1-1/4"-1-1/2" - 2	20	125
265	1-1/4"-1-1/2" - 2	25	125
335	1-1/4"-1-1/2" - 2	35	125
405	1-1/4"-1-1/2" - 2	40	125

*When flow rates exceed maximum GPM an external auxiliary bypass valve is required. See external bypass valve section for details.

CONNECTIONS

Before attaching the 2-inch unions to the inlet/outlet header, make sure the o-rings are properly seated in the grooves. Use AquaLube or equivalent non-petroleum based lubricant on the o-ring. Tighten the unions hand tight. Glue PVC piping directly to the unions.

INLET/OUTLETHEADER

Flange Gasket

Header Flange

Inlet

Fig. #2002.1

UNITHERMGOVERNOROPERATION

The patented Unitherm Governor is a thermostatic mixing valve specifically designed to maintain constant heater internal temperature between 105° to 115°F despite continually changing flow rates from the filter and changing pool temperatures. This narrow range is needed to prevent damaging condensation on the burn- ers which will occur if the heater runs for any length of time below 100°F. It is also needed to inhibit scale formation in the tubes by maintaining temperatures well below accelerated scaling temperatures.

INTERNAL AUTOMATIC BY-PASS VALVE

In addition to the Unitherm Governor, a built-in automatic by-pass valve is provided in the in/out header. While the Unitherm Governor responds to the changes in water temperature in the heater, the internal by-pass valve automatically responds to changes in water pressure in the piping system. Proper amount of water flow is maintained through the heater under varying pressures dictated by the conditions of the pump and filter.

Fig.#2003

EXTERNAL AUXILIARY BYPASS VALVE (Where Required)

An auxiliary bypass valve should be used when flow rates exceed 125 GPM (usually a high performance pump size larger than two horsepower will exceed this flow rate). This valve is required to complement the function of the automatic bypass valve, particularly when starting the heater in winter or early spring when the spa or pool temperature is down below 50°F. It also serves to eliminate needless pressure drop through the heater and accompanying reduction in the flow rate to the spa jets, etc.

From Heater To Heater

To Pool	From Pool
	AUXILLARY BYPASS VALVE
	(DO NOT USE GATE VALVE)
	Fig. # 8150.0s

AUXILIARY BYPASS VALVE ADJUSTMENT

To set bypass: With clean filter, adjustment is made by feeling the inlet and outlet pipes at the heater. Outlet pipes should be slightly warmer than inlet and comfort- able to the touch. If pipe is hot, close bypass; if cold, open bypass.

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