Patterson-Kelley TBIG-03 owner manual 4.0INSTALLATION

motorized gas valve (natural gas)

regulator*

pilot shutoff

natural gas connection manual shutoff

low gas

pressure switch*

propane connection manual

pilot regulator and solenoid valve

leak test valves

Installation

mechanical link to control air (Lo-Hi-Lo only)

burner

pressure tap

secondary shutoff, manual

high gas pressure switch*

motorized gas valve

shutoff

regulator *

low gas

pressure switch*

n.o. vent valve
(I.R.I. only)	Items with symbol must be
motorized gas valve	vented to outside.*	Refer to the
	drawings packed with your
(propane)
	boiler for additional information.

Figure 4-1 Piping Schematic for the Twin-Fuel Gas Train

4.0INSTALLATION

Gas Train Connection Sizes

	Natural Gas	Propane
700/1000/1200	1 1/4"	1"
Series
1500/1700/2000	2"	1 1/4"
Series

4.1GENERAL

Installation of the twin-fuel Gemini™ boiler is similar to that of the single-fuel model. Refer to “Thermific￿ Gas-Fired Boiler - Installation and Owner’s Manual - TBIG” pages 2 through 10.

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The following procedures are different from those for the single-fuel model, and are described in this Sec- tion:

￿￿Gas Piping

Gas Bleeds and Vents

￿￿Pre-Start Check List

￿￿Pre-Start Safety Checks and Adjustments Test of Ignition Safety System Test of Low Water Cutoff

Test of High Limit Control Test of Gas Pressure Switch