Honeywell CHRONOTHERM T8621A User Manual

Page 18

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18

System

Press

Look For This Response

Switch

This

Key

Position

Key

Down

Key Released

OFF

06

Blank

02

Blank

05

Blank

04

Blank

01

Blank

00

Blank

(CHECK

12

See note A .

EACH
POSITION)

OFF

08

Blank

13

Microprocessor mask
no. and revision no.

09

Blank

14

Blank

HEAT or

14

1st stage heating and

AUTO

SYSTEM LED on.

14

2nd stage heating
also on.

14

2nd stage heating off.

14

1st stage heating and
SYSTEM LED off.

NOTE: If single-stage heating system, press key twice

instead of 4 times; once to turn heating and SYSTEM
LED on, second time to turn off.

OFF

10

Blank

11

Normal operating
display.

END SELF-TEST

1

For electric heat fan operation—The fan will operate
with the heating system when fan switch is in AUTO.

A

HEAT displayed when system switch is in HEAT,
COOL when in COOL, HEAT and COOL when in
AUTO, neither when in OFF. Also, a four-digit code
is displayed, with each digit explained below.

T8621A,C,D

CHECKOUT

INSTALLER SELF-TEST (OPTIONAL)

IMPORTANT:

1. Thermostat must have ac power to perform self-

test. Relays will not toggle, codes will not be
present and thermostat will not manually exit
self-test without ac power.

2. Five-minute time delay on cooling does not function

during self-test.

Perform the following test as a check of all thermostat

functions. If thermostat does not respond as indicated,
thermostat must be replaced.

1. Press AHEAD and BACK keys at the same time.

While holding keys down, all segments of the display
should be on (see Fig. 18).

Fig. 18—All segments on display.

WARMER

2. Set the system switch to OFF. Press and release

AHEAD and BACK and PRESENT SETTING keys at the
same time to enter self-test.

3. Press each key as listed below, and look for re-

sponses listed as key is held down and released.

System

Press

Look For This Response

Switch

This

Key

Position

Key

Down

Key Released

OFF

03

Blank

07

Blank

15

Blank

COOL or

15

1st stage cooling,

AUTO

fan and SYSTEM
LED on.

15

2nd stage cooling
also on.

15

2nd stage cooling
off.

15

1st stage cooling,
fan and SYSTEM
LED off.

NOTE: If single-stage cooling system, press key twice

instead of 4 times; once to turn cooling, fan and SYS-
TEM LED on, second time to turn off.

(with fan
in AUTO)

M 525A

AM

SUN

MORNING

REPL

BAT

SET
PT

ROOM

PM

OUTDOOR

TUE WED THU FRI SAT TEMPORARY

MON

MIDDAY EVENING NIGHT

COOL ON HEAT ON

1

RUN

PROGRAM

CHANGE

TO LAST

PERIOD

PRESENT

SETTING

PRESENT

SETTING

AHEAD

COOLER

BACK

COPY

FROM

COPY

TO

PERIOD

CANCEL

PERIOD

DAY

SET

HEAT/COOL

SET

PRESENT
DAY/TIME

SET

PRESENT
DAY/TIME

SET

PRESENT
DAY/TIME

HOLD
TEMP

SET

PRESENT
DAY/TIME

SET

PRESENT
DAY/TIME

SKIP

NEXT

PERIOD

PRESENT

SETTING

PRESENT

SETTING

PRESENT

SETTING

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