Most boilers have 4 tappings 2 are for gravity and 2 are for pumped. When the pipe gets to a certain temperature the switch will close.
Circuit To Make Nest Thermostat Think There Are Separate
Pipe stat wiring diagram. 3 terminals with wiring clamps accepting wires up to 15 mm 2 mounting the l641a cylinder thermostat should be mounted 1 4 to 1 3 of the way from the bottom of the domestic hot water cylinder after removing a section of the insulation and cleaning the surface. For programmable thermostats and smart thermostats c wires are essential for setting a schedule or having your heat or air conditioner turn on at a desired temperaturewhile some units can run without a c wire even brands like nest recommend having one for optimal. You need a zone valve to open either the heating or hot water valve other wise the water has nowhere to flow and this will cause the pump to fail hope this works for you cjs. The common wire sometimes referred to as the c wire is whats responsible for delivering constant power to your thermostat. Permanent live one side of the stat switched return from the stat will join to the pump. The l641b pipe thermostat should be positioned less than.
Hope that makes sense. Anyone out there with a great mind for heating systems care to draw me a wiring diagram there is a warm flow oil boiler immersion pipe stat ufh valve manifold8 zones hot water valve hot water circulation towel warmer valve stat is whats on the towel rail upstairs heating valve 2 x 2 channel honeywell programmer 1x 1 channel honeywell programmer 1x stat for upstairs. Neutral straight to the pump. The last diagram i have drawn will allow the pump to run when all the heating and hot water is shut down via the pipe stat allowing heat to be dissipated. Wiring diagrams index system type thermostat units diagram number figure number 2 pipe cooling only transformer and non carrier relay board 24 v special request 42csv except vg and 42d 600 1000 cfm 1000 90000522 1 field suppliedinstalled controls line voltage and control valves 42csv and 42d. The pipe stat is a switch.
Usually the gravity feed will flow from a point high in the boiler to the upper tapping in cylinder and return to a point low in the boiler. The pipe stat is put on the gravity return pipe. This is basic requirement of gravity feed.