Lochinvar 497 - 2067 service manual Copper-fin How it works

Installation & Service Manual

The Copper-fin - How it works...

1. Heat exchanger 16. Low voltage connection board

The heat exchanger allows system water to flow through specially designed tubes for maximum heat transfer. The glass lined headers and copper fined tubing are encased in a jacket that contains the combustion process.

The low voltage connection board provides a location to tie in all of the low voltage contacts to the appliance. This is where most of the external safety devices are connected to the unit such as the louver proving switch.

2.Inner combustion chamber door

The inner combustion chamber door is a galvanized steel door which allows access for service, maintenance, and removal of the heat exchanger from inside the combustion chamber.

3.Blower

The blower pulls in air and injects air into the individual burners along with gas from the gas manifold where the mix is burned in the combustion chamber.

4.Gas valve

The gas valve allows the proper amount of gas to pass into the burner for combustion. The gas valve is biased with pressure from the combustion chamber to assist in regulation of the gas flow.

5.System / tank temperature sensor (not shown)

When connected, this sensor can be used as a system sensor or a tank sensor.

6.Inlet temperature sensor

This sensor monitors inlet water temperature. If selected as the controlling sensor, the appliance will maintain the set point temperature based on the reading at this sensor.

7.Temperature and pressure gauge (boiler only)

The temperature and pressure gauge monitors the outlet temperature of the appliance as well as the system water pressure.

8.Diagnostic display

The diagnostic display consists of six (6) lamps used to show all the major steps of operation and control malfunctions.

9.Burner

The burner is a ported stainless steel construction which uses a gas air mix to operate at a fixed input. Banks of burners are turned on or off to vary the firing rate.

10.Water outlet (system supply)

The water outlet is a pipe connection that supplies water to the system with connections for a flow switch (see #25), a relief valve (see #22), and a temperature and pressure gauge (boilers only) (see #7).

11.Water inlet (system return)

The water inlet is a pipe connection that receives water from the system and delivers it to the heat exchanger.

12.Gas supply pipe

The gas supply pipe on this appliance is 1 1/4'' diameter (Models 497 - 747) and 2" diameter (Models 987 - 2067) NPT. Please reference the National Fuel Gas Code charts for connection details.

13.Two-Stage Electronic Temperature Control

The electronic temperature control provides two-stage (high / low fire) operation by monitoring system demand.

14.Air intake

Fresh air for combustion is drawn through a filter provided at the air intake, located at either the rear or right side of the appliance.

15.Line voltage terminal strip

The line voltage terminal strip provides a location to connect all of the line voltage (120 VAC) contact points to the unit.

17.Front doors - upper and lower

The front doors provide access to the gas train as well as the blower, burners and other key components for service and maintenance.

18.Hot surface igniter (HSI)

The hot surface igniter is a device that is used to ignite the air/gas mixture as well as monitor the performance of the flame during operation. This device acts as a flame sense electrode.

19.Flame inspection window (sight glass)

The flame inspection windows, located on either side of the appliance, allow for visual inspection of the burners and flame during operation.

20.Gas shut off valve (downstream test cock)

The downstream test cock (when supplied) is in the gas train to ensure complete shut off of the gas to the burner in case of maintenance, inspection, or testing of the valve.

21.Manual high limit

Device that monitors the outlet water temperature to ensure safe operation. If the temperature exceeds its setting (field adjustable), it will break the control circuit, shutting the appliance down.

22.Relief valve

The relief valve is a safety device that ensures the maximum pressure of the appliance is not exceeded. Boilers operate on pressure only and are shipped from the factory at a rating of 50 PSI. Water heaters operate on temperature and pressure and are shipped standard as 150 PSI and 210°F (98.9°C).

23.Power switch

The power switch is used to engage and disengage power to the appliance on the 120 VAC circuit.

24.Air pressure switch

The air pressure switch is a safety device which ensures proper blower operation. The air pressure switch is wired in series with the low voltage control circuit in such a way that if the fan does not engage or shuts down prematurely the device will break the control circuit and the unit will shut down.

25.Flow switch

The flow switch is a safety device that ensures flow through the heat exchanger during operation. This appliance is low mass and should never be operated without flow. The flow switch makes contact when flow is detected and allows the unit to operate. If flow is discontinued during operation for any reason the flow switch will break the control circuit and the unit will shut down.

26.Drain port(s)

Location from which the heat exchanger can be drained.

27.Manual shutoff valve (not shown)

Manual valve used to isolate the unit from the gas supply.

28.Flue pipe

A pipe like enclosure that is placed over an appliance to improve natural upward convection of heat and thereby increase the dissipating ability of the appliance.

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