Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Rinnai e110cn connection to circulating pump

erkanerkan Member Posts: 1
Hi, I just installed Rinnai condensing combo boiler e110cn and have a question related connection of the circulating pump (for heating) and Rinnai RS100 controller. On the boiler itself there is a separate terminal for connection of the circulating pump, and the instructions state that the pump will go on whenever there is demand for heat or hot water. I don't really want circulating pump to go on whenever there is demand for hot water. Another thing that complicates the things is that I will be using RS 100 controller and instructions state this needs to be direct connection to bus line (not the thermostat terminal) on the boiler.

So the question is how can use a pump relay with RS 100 controller? Thanks in advance.


  • JackJack Member Posts: 1,044
    The RS100 is a control that works on a system like panel rads with Thermostatic heads and constant circulation. Is that what you are doing? If not, I think you will be better with an after market relay set-up.

    You are correct on the 4/5/6 terminals not being good for the system pump as that secondary pump will run on any call, heat or dhw. There are changes coming up on those 4/5/6/ terminals operation on the new heat only units, but not yours
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!