Lochinvar 497 - 2067 Boiler bypass requirements, Temperature / pressure gauge, Filling the system

Installation & Service Manual

4 Water connections

Boiler bypass requirements

The installer must ensure that the boiler is supplied with adequate flow without excessive temperature rise. It is recommended that this boiler be installed with a bypass in the piping if the maximum recommended flow rate is exceeded. The bypass will help to ensure that the boiler can be supplied with adequate water flow. Flow rates exceeding the maximum recommended flow will result in erosion of the boiler tubes. A typical bypass with a valve as shown in FIG. 4-6 will allow control of boiler flow.

Temperature / pressure gauge

This boiler is equipped with a dial type temperature / pressure gauge. This gauge is factory installed in the outlet side of the boiler piping. The gauge has one scale to read system pressure and a separate scale to read water temperature in degrees Fahrenheit. The temperature / pressure gauge is provided to meet code requirements. Water temperatures can be more accurately monitored from the data provided in the digital display in the Operator Interface.

Filling the system

All air must be purged from the system for proper operation. An air scoop and air vent must be located close to the boiler outlet and there should be a minimum distance between the cold water feed and the system purge valve.

1.Close all drain cocks and air vents.

2.Open the makeup water valve and slowly fill the system.

3.If a makeup water pump is employed, adjust the pressure to provide a minimum of 12 psi at the highest point in the system. If a pressure regulator is also installed in the line, it should be adjusted to the same pressure.

4.Close all valves. Purge one circuit at a time as follows: A. Open one circuit drain valve and let the water drain for at least five minutes. Ensure that

there are no air bubbles visible in the water stream before closing the drain valve.

B. Repeat this procedure for each circuit.

5.Open all valves after all circuits have been purged. Make sure there are no system leaks.

CAUTION Do not use petroleum based stop leak products. All system leaks must be repaired.

The constant addition of make-up water can cause damage to the boiler heat exchanger due to scale accumulation. Scale reduces flow and heat transfer, causing overheating of the heat exchanger.

6.Run the system circulating pump for a minimum of 30 minutes with the boiler turned off.

7.Open all strainers in the system and check for debris.

8.Recheck all air vents as described in step 4.

9.Inspect the liquid level in the expansion tank. The system must be full and under normal operating pressure to ensure proper water level in the expansion tank. Ensure that diaphragm type expansion tanks are properly charged and not water logged.

10.Start the boiler according to the operating instructions in this manual. Operate the system, including the pump, boiler and radiation units, for one hour.

11.Recheck the water level in the expansion tank. If it exceeds half the tank volume, open the tank to reduce the water level. Recheck pressure charge on diaphragm type tanks.

12.Shut down the entire system and vent all radiation units and high points in the system.

13.Close the water makeup valve and check the strainer and pressure reducing valve for sediment or debris. Reopen the water makeup valve.

14.Verify system pressure with the boiler pressure gauge before beginning regular operation.

15.Within three days of startup, recheck and bleed all air vents and the expansion tank using these instructions.

Water treatment

In hard water areas, water treatment should be used to reduce the introduction of minerals to the system. Minerals in the water can collect in the heat exchanger tubes and cause noise on operation. Excessive build up of minerals in the heat exchanger can cause a non-warrantable failure.

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