Taco RMB Boiler Return Temp Question

Jim_64

Both sensors are in the correct position and the return temp is set to 130. The boiler is set to 170 to allow adequate temp but it never reaches that. The RMB shuts the boiler off. Maybe the wiring between the boiler and RMB is incorrect. Where should the RMB connect to the boiler? The contractor has spoken to the distributor for help but as soon as he found out the RMB was purchased online the problem suddenly became "The board must be defective"! I'm not buying that since all other functions work well. Any help on how the RMB should interface with the boiler would be greatly appreciated. It is a Dunkirk non-condensing so return temp is very important. Thanks

Jim_64

Taco Boiler Return Temp Question

I have a recently installed Taco RMB set up for boiler protection. The sensors are in the correct locations and the DIP switch is in the off position. The boiler return temp is set to 130 degrees. When in operation the return temp drops to 115 before the boiler fires. Is this normal or should the boiler fire when the return temp drops to just under 130. As always thanks for the help.

singh

RMB

It's been a while since I installed an RMB , but you should make sure the sensor is attached well and insulated, to get true measure of return pipe.
I would not want the boiler return to go much below 130*.
Also make sure the differential is set closer.?

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Joe Mattiello

The Boiler protection feature is designed to minimize the cold water temperature back to the boiler using the min boiler set point found in your menu settings. The boiler sensor should be installed on the heat source side with the strap on sensor on the return side of the boiler loop. If the water temperature drops below the set point temperature the RMB will drop the injection pump percentage until the boiler catches up. We have to be clear on the functionality of the boil min temperature on the RMB, because usually boiler minimum is on start up, like the PC700-2 reset control. Hopefully this helps.