GSW 72090 manual Vii Combo Heating, System Requirements

VII) COMBO HEATING

This section serves as a guide for the installation and use of “Combo” heating systems utilizing a domestic water heater which has been specifically approved for such use (see Figure 19). It is written for those knowledgeable in the required trades and professionals involved in the design and installation of Combo Heating Systems.

It is the responsibility of the installer/designer to follow all applicable codes to ensure the effectiveness and safety of the installation.

System Requirements

The following requirements must be met for the installation of Combo Heating Systems:

1.The piping and components connected to the water heater for the space heating applications shall be suit- able for use with potable water. The system should be installed with new, non-ferrous piping. Do not use pumps, valves, fittings, solder, gluing and pipe sealant that are not completely compatible with potable water piping.

2.A water heater which will be used to supply potable water must not be connected to any heating system or components previously used with a non-potable water heating appliance. Do not use piping that has been treated with chromates, broiler seal or other chemicals and do not add chemicals to the water heating piping. Do not introduce toxic chemicals, such as those used for boiler treatment, into the potable water used for space heating.

3.Do not use this heater as a replacement for an existing boiler installation.

4.If the space heating water system requires water with temperatures in excess of 60°C (140°F), a mixing valve, or other means to temper the water and reduce scald hazard potential, must be installed in the potable hot water supply.

5.If the heater is installed with a back-flow preventer on the incoming water line or in a closed system, a diaphragm-type expansion tank must always be installed in the system to prevent the T&P from relieving due to thermal expansion.

6.Proper sizing of the water heater for the given space and potable heating application is essential to ensure adequate heating capacity. The sizing and installation of such combination system must be performed by quali- fied personnel and be in accordance with public utility requirements and/or codes having jurisdiction.

The sizing of the water heater should be based on the design heat loss of the structure to be heated plus the potable water requirements.

IT IS IMPORTANT THAT THE WATER HEATER USED BE OVERSIZED TO ALLOW ADEQUATE HEATING AND POTABLE WATER HEATING CAPACITY.

CHECK VALVE CIRC. PUMP

HOT WATER	COLD TO
TO HOUSE	WATER HEATER

WATER

HEATER

AIR

HANDLER

MASSACHUSETTS

CODE DOES NOT

ALLOW THIS TYPE

OF INSTALLATION.

RADIATOR OR RADIANT FLOOR PIPING ARE

VIABLE ALTERNATIVES TO AIR HANDLER.

Figure 19 Example Of Combo Heating Piping Schematic

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