background image

 

Page 1 of 5 

 

 

INSTALLATION AND OPERATING INSTRUCTIONS 

 

Astro 2 Series - Hot Water Re-circulation System 

 
 

TYPICAL APPLICATIONS 

 
Armstrong Astro 2 hot water re-circulation systems automatically circulate 
water through domestic hot water distribution pipes. This helps to ensure that 
everyone in the household has “instant” hot water at the tap when they need 
it, while also helping to conserve water and save water heating energy costs. 
All systems are assembled, wired, tested, and then shipped from the factory, 
ready for installation. 
 

HOW IT WORKS 

 
In normal operation, the Astro 2 automatically starts re-circulating water throughout the hot water distribution system 
whenever the timer enables activation. The timer can be set for one or more activation periods per day. An activation 
period consists of a multiple (up to 96) of 15 minute time intervals. The timer includes manual on and off overrides to 
normal automatic operation. 
 
Some models are equipped with an Aquastat, intended for use on metallic piping. The Aquastat enables operation only 
when the sensed water temperature is below 85°F (25°C). Once activated, the circulator operates until either the water 
temperature reaches 105°F (41°C), or the current timed activation period ends. 
 

TECHNICAL DATA 

 

TECHNICAL DATA 

Power Connection 

5.0 ft (1.5 m) power cord, molded duplex plug with ground 

Environment 

Indoor use only 

Max. Working Pressure 

100 psi (689 kPa) 

Ambient Temperature 

39°F (4°C) to 104°F (40°C) 

Max. Water Temperature 

140°F (60°C) 

Low Temperature Switchpoint

1

 

85°F (29°C) ±10% 

High Temperature Switchpoint

1

 

105°F (40°C) ±10% 

Clock/Timer 

12-hour analog clock with AM/PM indication 

Timer Settings 

Individual mechanical toggles for each 15 minute interval over 24 hours 

Manual Override 

3 position slide switch; on/auto/off 

1

High/low temperature switch points are as measured on pipe surface with the Aquastat (-TA models only). 

 

MATERIALS OF CONSTRUCTION (Wetted Parts) 

Pump Casing 

Lead Free Bronze* or Stainless Steel* 

Pump Shaft 

Polyether Imide (PEI) 

Impeller Ceramic 

Bearings Ceramic 

Bearing Seal 

EPDM 

*Complies with section 116875 of the California Health and Safety Code and 
Vermont Act 193 (Lead content of wetted surface is 0.25% or less.) 

 

 
 
 
 
 

FILE NO.: 

10.812 

DATE: 

Oct. 20, 2010 

SUPERSEDES: 10.812 
DATE: 

Apr. 20, 2010 

Reviews: