Navien CH-240 and additional pump

attn

Anyone have experience installing <strong>CH-240</strong> in simple 2 store building. Is additional pump required for such simple installation i.e single thermostat with no multiple zones ? I've just confused little bit that some contractor saying that additional water pump required even unit itself already have build-in water circulation pump.  Manual not clear about this too. It doesn't indicate that pump is required for primary heating loop and only for secondary and other loops. What if I only have a primary heating loop ?

RobbieDo

Pics

Do you have pics of how this is piped?? It sounds like you don't have primary/secondary piped in properly. Thanks

Gordan

Depends on the pressure drop and flow requirements

The built-in pump may not (and probably does not) be sufficient to maintain the required flow against your system pressure drop. Hence the recommendation (requirement?) to pipe the appliance primary-secondary, and decouple the system flow from the appliance flow.

attn

Navien CH-240 and additional pump

Thank you. I understand I need extra pump. Which one would be good for 2 floors building + basement. Is 3 speed grundfos 15-58 is a good choice ?

Ironman

More Info is Needed

In closed loop, the bldg. height does not determine the size of the circulator.



You will need to know your heat loss, gpm required, head loss, type of emitters, etc.



See the attached thread:



http://www.heatinghelp.com/forum-thread/135487/tradeservices-tech

CMadatMe

Why?

Why are you installing a water heater as a primary heat source? To anwser your question you do need to pri/sec so yes you need an additional system side pump. How did you wire in your low water cut-off and additional high limit aquastat with manual reset? This is commercial and that would be a requirement here.