UHA STANDARD UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL
SECTION 3: CRITICAL CONSIDERATIONS 3.1 Basic Information
UHA[X][S] heaters have automatic ignition burners for ON/OFF operation only.
3.2 Manufactured Units
a
•Separated Combustion: A separated combustion unit shall feature an enclosed, sealed burner box. A piece of flexible air duct connects this burner box to a flange on the cabinet. Combustion air should be ducted from outside the heated space, with the ductwork connecting to the unit with the use of the flange.
•Stainless Steel Heat Exchanger: A stainless steel heat exchanger unit shall consist of heat exchanger tubes, heat exchanger tube supports, heat exchanger tube plates and vent box produced of 409 stainless steel.
The use of stainless steel heat exchanger unit is recommended when air inlet temperatures are below 40° F (4.4°C) or temperature rise is less than 40° F (22.2° C) as condensation may form on the heat exchanger resulting in corriosion that may shorten its life.
3.3Location and Suspension All models:
• Must be installed indoors.
•Must be installed in a level position with horizontal discharge.
•May be mounted on a shelf of
•May be suspended from above (See Page 10, Figure 5) or from wall brackets of sufficient strength to support the heater as listed in the Technical Data Table on Page 49, Section 16.2. Drop rods must be a minimum of 3/8" diameter mild steel. Four suspension points (3/8" nuts) are located on top of the heater.
•Must be installed in a manner which allows access to all serviceable components. See Page 7, Figure 4 for details.
3.4 Minimum Required Installation Clearances
Clearances around the heater and vent must be as indicated on Page 7, Figure 4 and Page 13, Figure 6 to ensure access for servicing and correct operation.
3.5 Ventilation
It is important to ensure that there is adequate air space around the heater to supply air for combustion, ventilation and distribution in accordance with local and national codes on Page 11, Section 7.
3.6 Gas Supply
It is important that the gas supply pipe is sized correctly to provide the inlet pressure as stated on the heater data plate. The gas supply pipe and electrical connections must not support any of the heater's weight on Page 19, Section 9.
3.7 Electrical Supply
A permanent 120 V / 60 Hz / 1 Ø electrical supply is required for the main electrical power. The heater also requires suitable controls in accordance with See Page 21, Section 10.
3.8 Vent
Choose heater orientation to allow for the proper location of the vent. Each heater must be fitted with a correctly sized sealed vent system.
If vented horizontally, no other appliance may be connected to the vent. See Page 11, Section 7.
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