ROBERTSHAW 2000DER GAS VALVE

GAS VALVE KNOB SHOWN

MANIFOLD

IN OFF POSITION

PRESSURE TAP

INLET PRESSURE TAP

MANIFOLD PRESSURE ADJUSTMENT

SCREW UNDER CAP

FIGURE 10

12.If lockout occurs, repeat steps 1 through 9.

13.If appliance still will not operate, follow the instructions “TO

TURN OFF GAS TO UNIT” and call your service technician or gas supplier.

TO TURN OFF GAS TO UNIT

1.Set thermostat to lowest level.

2.Turn off all electrical power to unit if service is to be performed.

3.Depress knob on gas valve; knob will snap to OFF.

HEATING SEQUENCE OF OPERATION

1.When the thermostat calls for heat, the combustion air blower starts immediately.

2.Combustion air pressure switch proves blower operation before allowing power to the ignition controller. This switch is factory set and no adjustment is necessary.

3.After pre-purge of approximately 30 seconds, the spark ignition is energized and the solenoid valves open in the gas valve.

4.The spark then ignites the gas, the ignition sensor proves the flame and the combustion process continues.

5.In the event that the flame is not detected after the first

10-second trial for ignition, the controller will repeat steps

3 and 4 an additional two times before locking out the gas valve. Ignition control will then automatically repeat steps 3, 4, and 5 after 60 minutes.

To interrupt the 60-minute lockout period, move thermostat from “Heat” to “OFF” then back to “HEAT.” Heating sequence then restarts at step 1.

6.The burners shall light without noticeable crossover delay. There shall be no flame lifting from the burner heads, flashback or burning within the burner. The flames shall be predominantly blue in color and shall be approximately centered in the tubes with no apparent impingement taking place.

7.The ignition control will energize the fan approximately 45 seconds after ignition is established.

8.After the thermostat demand is satisfied the gas valve is closed; 5 seconds after the demand is satisfied the combustion air blower is shut off.

9.The control center shall shut off the system fan approximately

150 seconds after the gas valve is de-energized.

IGNITION CONTROL LED

The ignition control board contains a green LED which indicates the following:

TABLE 3

IGNITION CONTROL LED

OPTIONAL GAS CONVERSION KIT

LED

UNIT OPERATION

 

 

 

 

Slow Flash*

Normal Operation - No call for heat

 

 

Fast Flash

Normal Operation - Call for heat

 

Current signal at FLAME terminal 0.6 to 1.0 microamps

 

 

2 Flashes

System lockout - failed to detect or sustain flame

 

Current signal at FLAME terminal <0.6 microamps

 

 

3 Flashes

Pressure switch failed closed before CAB is energized

 

or failed open after CAB is energized

 

 

4 Flashes

High limit or rollout switch open

 

 

5 Flashes

Flame sensed and gas valve not energized

 

 

Steady Off

loss of power

 

 

Steady On

Ignition control failure

 

 

*When thermostat is placed in continuous fan mode LED will slowly flash.

Unit not available for conversion at this time.

ADJUSTMENTS

HIGH ALTITUDE

Units may be fired at full input up to 2000 ft. (610m) above sea level. Above 2000 ft. (610m), manifold pressure must be adjusted on some units. Adjust pressure regulator to pressure shown in table 4 for natural gas and table 5 for LP/propane gas.

GAS FLOW

To check for proper gas flow to the combustion chamber, determine the Btu input from the appliance rating plate. Divide this input rating by the Btu per cubic feet of available gas. Result is the required number of cubic feet per hour. Determine the flow of gas through the gas meter for two minutes and multiply by 30 to get the hourly flow of gas.

GAS PRESSURE

1.Check gas line pressure with unit firing at maximum rate. A

Enerco Compact Unit Heater

12

Operating Instructions and Owner’s Manual

Page 12
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Enerco HSU 75, HSU 45 operating instructions Adjustments

HSU 45, HSU 75 specifications

Enerco HSU 75 and HSU 45 are standout models in the realm of portable heating solutions, designed for efficiency and convenience. These units serve a range of applications, from construction sites to workshops, and even for personal use in outdoor settings. With their robust engineering and advanced features, they are ideal for anyone needing reliable warmth in cold conditions.

One of the main features of the Enerco HSU series is their impressive heating capacity. The HSU 75 offers a maximum output of 75,000 BTU, making it suitable for larger spaces, while the HSU 45 delivers 45,000 BTU, perfect for smaller areas. This flexibility allows users to choose the right model based on their specific heating needs.

Both models utilize a forced air heating system, which efficiently circulates warmth throughout the space. This technology ensures rapid heating, allowing for immediate relief from the cold, an essential feature in situations where time is of the essence.

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Safety is paramount with Enerco heaters, and both the HSU 75 and HSU 45 come equipped with safety features such as automatic shut-off sensors and flame failure devices. These innovations give users peace of mind, knowing that the unit will operate safely even in unpredictable environments.

Portable design is a hallmark of these heaters, featuring built-in handles and a lightweight structure. This makes it easy for users to transport the units from one location to another, enhancing their versatility in use.

Finally, both models are compatible with various fuel sources, allowing for flexibility based on user preference and availability. Whether using propane or natural gas, users can enjoy efficient heating tailored to their requirements.

In conclusion, the Enerco HSU 75 and HSU 45 represent a perfect blend of power, safety, and portability. Their advanced features and durable build make them ideal companions for anyone needing dependable heat in diverse scenarios. With these units, warmth is always within reach, ensuring comfort regardless of the harshness of the outdoor conditions.