NCB 240 recirculation pump

[Matthew Bohas]

Hello everyone,

Can I use a recirculation pump with the navien NCB 240?

Currently I do not have a recirculation line, I imagine I would need one installed for this to work. I only see the recirculation with the npa on naviens website.

One plumber has suggested adding a manifold at the furthest faucet instead of adding a recirculation line. Thoughts?

 

[Fitter30]

You will still a pump. Flowing over 1/2 gallon per minute to make flow switch.

 

[Sponsor]

 

[Matthew Bohas]

sorry? Confused

 

[Fitter30]

Heating side has a built in pump dhw doesn't. There are valves that can be pipied in the furthest fixture to pump hot water back into the cold water but not sure if they would work.

 

[Bannerman]

Navien NPA is a tankless water heater series with a built recirculation pump, buffer tank and recirculation return inlet.

Since your combi boiler is not equipped with an internal DHW circulation pump, you will need to add an external pump with the recirculation flow to return through the DHW cold water inlet. The flow rate through the NCB's DHW internal circuit will need to be rapid enough to activate the flow switch so the unit will fire the burner when required.

See page 16 of the NCB-E Application Drawings
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.navieninc.com/app/W1siZiIsIjIwMTgvMDgvMjMvMTkvNTgvNDQvYjJmN2U0NGEtNjZmMS00NjhlLWJhNGYtZjZkZjUxMjNjNjQ1L05DQi1FIEFwcGxpY2F0aW9uIERyYXdpbmdzLnBkZiJdXQ/NCB-E%2520Application%2520Drawings.pdf%3Fsha%3D9333d3f42dfea666&ved=2ahUKEwjL1JDrhZDtAhXlTN8KHTlWCoEQFjAAegQIAxAB&usg=AOvVaw3mwjDoNCyEtpBWuSpE_v5T

Info page for NaviCirc
https://www.navieninc.com/accessories/navicirc