Circulator Pump is pushing water through neighbor zones

[galijoe]

Hello - Great Website.
We have a Bosch Combi 100 Greenstar boiler. There are two zones (upstairs & downstairs) each with their own Grundfos alpha digital circulator pump. When the downstairs thermostat calls for heat the proper circulator turns on however; it forces hot water through the upstairs zone also. We have supply and return temperature gauges on each zone. The temperatures for both zones are identical when only one circulator is running. This causes the upstairs to get extremely hot. We have the grundfos set to pump speed 1. The circulators have check valves installed. Any suggestions to keep the zones separated? Could it be a pressure issue? too much?
Appreciate your help. Joe.

 

[Tom Sawyer]

It's either a piping issue or there aren't any flow check valves. Why not call whoever installed it?

 

[Sponsor]

 

[galijoe]

It's either a piping issue or there aren't any flow check valves. Why not call whoever installed it?

I installed it and it has check valves that are installed the right way. What I didn't install was the Webster close T's on the primary and the secondary returning and leaving the boiler. I was not aware that it has an effect on the pressure. Everything else is installed exactly like the Bosch video. Whats your thoughts on this being the problem?

Thanks Joe

 

[Tom Sawyer]

That's the problem.

 

[BadgerBoilerMN]

Bosch video...

It is extremely unlikely that the systems needs two pumps.

Pay someone to sort out the piping for you, and start over.

We install the Bosch units, never a problem.



DIY design, always the first mistake.