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INSTALLATION AND OPERATING INSTRUCTIONS

24-HOUR TIMER and AQUASTAT CONTROL ACCESSORY

FILE NO:

11.87

DATE:

Apr. 22, 2004

SUPERSEDES: 11.87
DATE:

Feb. 24, 2004

TIMER APPLICATION

The Armstrong 24-hour timers provide On/Off pump control according to preset operating
times in order to increase comfort and improve the overall efficiency of domestic hot water
re-circulation systems. The 24-hour timers are designed only for use with specified
Armstrong Astro series wet rotor circulators installed in indoor hot water re-circulation
applications.

Typical timer applications will cycle the pump at preset times, allowing the user to select
operation of the circulating pump during high peak usage periods in order to decrease the
delivery time to outlet fixtures and reduce wasted water.

The timer control is programmable to ¼ hour intervals within a 24-hour time frame utilizing
a user friendly analog clock timer with hour and minute hands, two directional arrows, and
AM/PM time setting.

AQUASTAT APPLICATION

An optional aquastat is available for constant circulation applications to maintain
temperature between 85ºF and 105ºF (29ºC and 41ºC). The Armstrong aquastat
control accessory is designed for use with Astro Series wet rotor circulators in potable
hot water re-circulation installations.

The aquastat control automatically turns the circulator on when the temperature in the hot
water line falls below approximately 85ºF (ON condition - for example when there is low demand on the hot water
supply). The control turns it off again when the temperature exceeds 105ºF (OFF condition - as in the case of
periods with high demand).

TIMER AND AQUASTAT APPLICATION

The 24-hour timer and aquastat can also be used together giving a comprehensive time and temperature actuated
pump control in a domestic hot water re-circulation system. Typical application of the timer and aquastat combination
will circulate water only when both time and temperature ON conditions are initiated.

TIMER FEATURES

Easy to install and program

Time actuated 24-hour on/off pump control

Hour and minute time setting with AM/PM function

Manual override switch modes

Rugged construction - steel enclosure

Clear plastic cover for dust and moisture protection 
of the clock face

Designed specifically for hot water re-circulation 
applications

UL Listed

AQUASTAT FEATURES

Easy to install

Temperature actuated pump control

Environmentally sealed enclosure

Surface sensing through snap acting bimetalic disc

UL Listed

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