What is ZC and ZR terminals?

For the cold start, the X, X goes to the TT terminals in the boiler control. When an aquastat has the ZC and ZR terminals, the ZC is connected to the low temperature switch of the aquastat and to the ZC terminal of the Taco control. The ZR is connected to the ZR. These will be 120 Volt wiring.

How do I know if my Aquastat is bad?

Check the heating boiler temperature gauge If the boiler temperature is at or above the HI limit set on your boiler aquastat or upper limit control switch then something is abnormal and unsafe and you should turn the system OFF immediately and call for heating system service and repair.

How much does it cost to replace an Aquastat?

replace a boiler Aquastat relay – $ 700. replace inducer blower motor – starts @ $ 600. Replace contact Relay -start @ $400.

How does an Aquastat relay work?

The aquastat monitors the water temperature in the boiler through the use of a copper bulb that stays in contact with the water inside the boiler and that shuts down the boiler automatically if the low- or high-temperature set point is exceeded.

What does ZR and ZC mean on an aquastat?

When an aquastat has the ZC and ZR terminals, the ZC is connected to the low temperature switch of the aquastat and to the ZC terminal of the Taco control. The ZR is a 120 Volt supply to the burner circuit to fire the boiler, but this goes through the high limit switch to control the boiler water temperature.

What does cold start boiler mean?

Cold-start unit: This is any heating appliance that does not maintain temperature, but does produce domestic hot water. The concept allows the boiler to remain cleaner throughout the operating year and actually accelerates recovery during extended periods of domestic hot water draw.

How do I reset my Honeywell aquastat?

When the temperature of the controlled medium drops to the high limit setting minus differential, push the manual reset button and the system should be operative again. Reset control to proper high limit setting.

How do I adjust my Honeywell Electronic aquastat?

To discourage unauthorized changing of Aquastat® settings, a procedure to enter the adjustment mode is required. To enter the adjustment mode, press the UP, DOWN, and I buttons simultaneously for three seconds. Press the I button until the feature requiring adjustment is displayed: HL – High Limit.

What is a Aquastat control?

An aquastat is a device installed in hydronic water systems for the purpose of controlling temperature within the boiler. An aquastat is similar to the furnace limit switch in operation, maintaining a safe operating temperature for the central heating unit.

What is ZC on Aquastat?

What is a Aquastat well?

Honeywell Aquastat L4006A is an immersion type device for limiting or regulating the temperature of liquids in boilers, storage tanks, and other applications where temperature control is required. Honeywell L4006A1678 is used for high limit or low limit control.

How do you start a cold boiler?

Begin warming the boiler slowly, allowing for gradual expansion. Open the (automatic) non-return and main steam stop valves. Open all drain valves in the system to allow condensate to exit the piping before steam fills the system.