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Plumbing in the Home/shutdown domestic hot water


Hello Jay,
I have an oil fired hot water boiler that also makes the domestic hot water for 4 apartments. I have separated the 4 units from the boiler and installed electric water heaters that they each now pay their own utility. I only want to shutdown the domestic hot water permanently in the boiler. How do I go about doing that so that during heating season the boiler operates as normal for heat? Also, what should be done with the water supply connected to the domestic hot water coil?

Hope you can help. Thank you,

Daniel, You will have to disable the controller for the domestic water coil. Basically the coil is nothing more that another zone. Not knowing how it is wired, It is impossible to  give exact directions. Generally, Somewhere in your system there is an aquastat that tells the boiler to heat up to heat your domestic hot water. Disconnecting that aquastat will stop the boiler from firing  for domestic hot water and not affect the heating control. That controller has to be disconnected. Probably a set of wires leading into your boiler control. Your manual will tell you which terminals are for the coil. The wiring schematic for the model controller will also tell you as will the aquastat controller (if you have one) Your system may have only one controller that does everything.  As for the cold water supply to the coil, cut and cap the supply line and the outgoing hot line. leave the inlet and outlet of the coil open. If there are valves on the supply in and the return out of the coil, then just shutting them will do. I would not remove the coil unless you have the original plate that was removed when the coil was installed. if it came from the factory installed, leave it in.


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Jay Nicholas


Plumbing & Heating (warm air, hot water & steam heat)


40 years in the business, 40 years as a lic. master plumber in NY State. Retired

Graduated Magna cum laude at the School of Hard Knocks

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Commercial, residential and light industrial. You name it ...I have probably worked on it

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