Installing a thermostat

Old 10-21-01, 07:41 AM
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I have a Honeywell clock thermostat. It is the chronotherm T882A 1047 1.
The clock is no longer turning. I removed the T-stat from the base and
notice 4 wires ( c, c1, r, w ). two wires to the clock/transformer and
two wire for the heating. 24V transformer, conventional unit. Do I have
to do anthing when putting the same t-stat back on the base? recalibrate

I plan to replace the unit with the Honeywell T8090, a similar unit with
the clock on the left side. Should I turn the power off at the circuit
breaker? Does the unit have to be recalibrated.

Thanks for any assistance inadvance


Old 10-23-01, 01:10 AM
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Definitely turn off the breaker when you work on anything. The only calibration needed is to set the heat anticipation setting in the new thermostat. A small lever needs to be set to the setting found on the gas valve for your furnace. You should also make sure that the thermostat is level, of you will have accuracy problems.

Enjoy your day!
Old 12-23-06, 10:16 AM
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Adjusting a T882A 1047 1

I've just moved into a house with a ChronoTherm T882A 1047 1. It appears to work, but short-cycles. Does anyone know how to properly set one of these, including basic operation of the lower and upper temperature settings, use of the clock/hi/low mechanism, and an adjustment lever on the lower right side?

Old 12-23-06, 12:05 PM
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Raulman, the new T8090 uses batteries to run the clock. When you wire it up the old wires that went to the "C" terminals will be spare. Either tape them up good or disconnect them at the controller. Just reconnect the
"R" and "W" wires. Be sure to shut off the power to the furnace or boiler first. Be sure that the two "C" wires don't get shorted together or you'll damage the control transformer. I would also think that you got a new base with this unit. Use it.

JD, you have an obsolete unit. I couldn't find anything on it. Usually short cycle means the heat anticipator lever needs to be set to a higher number.

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