I am looking at the system in the picture below. Bought a house with it installed 10 years ago. The previous owner (not original) admitted the system was not very good.
I think I have identified the problem but would like anyone's confirmation or another opinion.
Here's what I think.
Looking at the pic:
There is a EB-WX-27 electric boiler just to the right with a pump in-line to the upper pipe (supply).
I suppose the installer called this the primary loop. The bottom loop is the return to boiler.
Then he piped 8 zones out of this upper supply pipe to PEX underfloor heating.
He returned the 8 zones back to each zone's Taco circ pump, and then into the return loop pipe.
Without debating the position of the zone pumps in the return, it seems to me that he has confused his thinking about primary/secondary correct piping.
Because the supply to the zone is off the primary loop supply and the return is to the return loop, there is hydronic coupling that invites hot water flow through the zone piping even with the zone pump off.
Previous owner's comments about poor perfomance, and my own experience this season so far confirms that all zones get heat even without their zone pumps on and only one zone calling and that 1 pump on.
His mistake, I think, is that this system may have worked if he used a correct piping method of primary/secondary, meaning the supply and return taps to the zone were 6 inches apart on the primary loop.
If that 6 inch was observed then the zone(s) without a pump on would be hydronically de-coupled from the primary loop and supply water would bypass that zone completely.
This piping that exists in the pic might work if valves were installed in each zone loop, but that is time and expense. I can only guess that the installer was trying to improve the system, thinking if zone valves are good then zone pumps are better. But that turns out to be wrong, I think, because the zone pumps pass water even when off.
All opinions welcome.
I think I have identified the problem but would like anyone's confirmation or another opinion.
Here's what I think.
Looking at the pic:
There is a EB-WX-27 electric boiler just to the right with a pump in-line to the upper pipe (supply).
I suppose the installer called this the primary loop. The bottom loop is the return to boiler.
Then he piped 8 zones out of this upper supply pipe to PEX underfloor heating.
He returned the 8 zones back to each zone's Taco circ pump, and then into the return loop pipe.
Without debating the position of the zone pumps in the return, it seems to me that he has confused his thinking about primary/secondary correct piping.
Because the supply to the zone is off the primary loop supply and the return is to the return loop, there is hydronic coupling that invites hot water flow through the zone piping even with the zone pump off.
Previous owner's comments about poor perfomance, and my own experience this season so far confirms that all zones get heat even without their zone pumps on and only one zone calling and that 1 pump on.
His mistake, I think, is that this system may have worked if he used a correct piping method of primary/secondary, meaning the supply and return taps to the zone were 6 inches apart on the primary loop.
If that 6 inch was observed then the zone(s) without a pump on would be hydronically de-coupled from the primary loop and supply water would bypass that zone completely.
This piping that exists in the pic might work if valves were installed in each zone loop, but that is time and expense. I can only guess that the installer was trying to improve the system, thinking if zone valves are good then zone pumps are better. But that turns out to be wrong, I think, because the zone pumps pass water even when off.
All opinions welcome.