AquaMotion has developed an outdoor hot water recirculation pump called the Aqua-Shield™. The pump installs on dedicated return line tankless heaters and it intended to saves on expensive air intake/exhaust systems. The company also says the pump saves up to 15,000 gallons of water annually. Pump is freeze and insect protected, rain and sprinkler safe. The control box has built-in timer visibility and an anti-tampering feature.
 
--AquaMotion 

www.AquaMotionHVAC.com