Raypak 300, 850 Flow Switch, Low Water Cut-OffOptional, High & Low Gas Pressure Switches Optional

Flow Switch

This standard, dual-purpose control, mounted and wired in series with the main gas valve, shuts off the boiler in case of pump failure or low water flow.

Fig. 27: Flow Switch

Low Water Cut-Off (Optional)

The optional low water cut-off automatically shuts down the burner whenever water level drops below the level of the sensing probe. A 5-second time delay pre- vents premature lockout due to temporary conditions such as power fluctuations or air pockets.

Fig. 28: Low Water Cut-Off

High & Low Gas Pressure Switches (Optional)

The optional low gas pressure switch connection mounts upstream of the gas valve (on the inlet flange to the gas valve) and is accessible through the remov- able access panels on the rear of the boiler to reset the gas pressure switch, as necessary. It is used to ensure that sufficient gas pressure is present for prop- er valve/regulator performance. The low gas pressure switch automatically shuts down the boiler if the gas supply drops below the factory setting of 3.0 in. WC for natural gas or propane gas.

The optional high gas pressure switch connection mounts down-stream of the gas valve. Special ports are located on the backside of the gas valve and accessible from the front of the boiler (to reset the gas pressure switch), as necessary. If the gas pressure regulator in the valve fails, the high gas pressure switch automatically shuts down the burner.

Operation of either the High or Low Gas Pressure Switch will turn on an LED inside the switch housing. Push the top of the plastic switch housing as shown in Fig. 29 to reset a tripped pressure switch. The LED will go out when the switch is reset.

Fig. 29: High/Low Gas Pressure Switch

Blocked Vent Switch

This heater is equipped with a blocked vent pressure switch to prevent the operation of the boiler when too much of the vent is blocked. This switch is located on the left side of the heater near the left rear corner.

Fig. 30: Blocked Vent Switch

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