Pressure Limit Switch In Boiler

The high pressure limit switch is a safety device used to shut down the operation of the gas or oil burner when the pressure boiler pressure exceeds a preset level commonly 5 to 8 psi the high pressure switch is connected to the boiler by a pigtail pipe.

Pressure limit switch in boiler.

A restart the forced draft fan. This gauge displays the heating boiler internal pressure and temperature. Over 30 psi boiler pressure will cause the pressure relief valve to open. Typical pressure for a residential boiler serving a two story home would show 12 psi cold and less than 30 psi hot.

Normally the blower fan will turn off at 180 degrees but if something goes wrong with that device the high limit switch will trip which cuts power to the blower fan and solenoid. If the gas pressure is too low or too high the burner will not operate correctly. B reset the lockout on the high limit controller. When a room thermostat calls for heat the ibc starts the system circulator and blower.

A separate high limit control usually mounted near the top of the heating boiler monitors boiler temperature and shuts off the oil or gas burner when that limit has been reached. Set above the operating limit off point this control has a fixed differential so the switch is closed unless the set point is reached and it breaks power to the control circuit. Pressure and temperature gauge on hot water or hydronic heating boilers. D switch the boiler control to the low fire model.

Individual high limit and low limit relay switches on heating boilers. These may be provided on older heating boilers. Honeywell pressuretrol controller with a range of 10 150 psi manual reset and a 1 4 npt female connection to siphon loop. C6097 series switches can help reduce your inventory because they can be used with older stand alone component valves as well as newer valves.

The gas pressure switches are to verify that the gas pressure is within a safe range. The ibc runs the blower to purge the boiler flue passages then turns on the igniter and lets it warm up. Some boilers require gas pressure switches to meet code compliance. A high limit switch will trip when it senses the outdoor boiler water jacket temp reaches 190 degrees.

These safety limit pressure switches can be used in positive or differential pressure systems to sense natural gas liquid propane lp gas or air. In the case of a high pressure occurrence or operating control failure power to the burner is automatically shut off and the control needs to be manually reset for a. C reset the boiler main power supply. Pressure switch inlet water sensor and boiler limit circuit to operate the circulators gas valve igniter and blower.