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[Joepa82]

I recently put in a system that has a taco 009 circulation pump that circulates water to the sidearm exchanger for our hot water then travels to a heat exchanger in our forced air furnace then travels back to the stove. We teed off of the supply line between the 009 circulation pump and the sidearm heat exchange to feed to zones of baseboards. I put 2 taco 007 priority zone pumps to supply 2 different zones of water baseboard heat that then dumps into the cold return line when the zone calls for heat. We have swing valves directly after the zone pump mounted vertically. Somehow water is passing through our baseboard zones even with the pump off and we cant figure out why. If anyone has some suggestions to what the problem could be I would appreciate it.

[RSI]

You need to move the return line for the baseboard zones to the same pipe as the supply. The tees should be as close together as you can get them.

[Joepa82]

The reason the lines are setup like that is because The baseboards are in a garage that has been turned into a living space and the floor is concrete. Theres no way to bring the return lines back to where the supply line is. Why would it matter how close the fittings are? If using zone pumps shouldnt it not allow water to pass by when not in use? And having a flow check valve shouldnt allow it to travel backwards through the system? some suggestions that i have gotten is that the swing valve has to be horizontal, the circulation pump should be after the zone pumps. I've heard many different theorys but i want to know for sure which one is correct before i tear apart my whole system. Thanks for the response rsi maybe you have reasoning for the fittings to be closer together.

[RSI]

Pumps don't stop flow and really don't have much restriction at all when not running.
You might be able to try pumping backwards and see if the checkvalves can stop the main pump from pushing water through those zones. If that doesn't work you probably will need to install zone valves.

[Joepa82]

Gotchya. I did think about reversing the pumps to draw water through the system in the opposite direction. It seems like the force would be a lot less on the pump since where it tees off it is 3/4 from 1 inch on the return but at the supply its still at 1 inch. and there would be the most pressure from the pump at the t where i supplied the zone pumps since its the first thing cut into the supply line.
would it be better to have a single 1inch swing valve after the pumps if i reversed the system?

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[Hydronix]

All it is , is excessive head pressure from the 009 that is strong enough to open the "swing checks" . If you had IFC -internal flow checks in the pump body or in the valve flanges, this would be the correct check for the application and eliminate the problem. A 009 has a very steep pump curve, and since those are the first zones the pump 'sees" on its way to the rest of the system. I would hate to see you put in ZV's when the proper check will do. By having closely spaced tee's , it would likely also solve the ghost flow, but then your sidearm and WAHX would see much lower temps, like 20-40* lower.

[tawilson1152]

What about putting a valve before the 007's and throttling it down? I had a similar problem and by adjusting valves and putting a variable speed switch on my primary pump I took care of it.

[Hydronix]

What about putting a valve before the 007's and throttling it down? I had a similar problem and by adjusting valves and putting a variable speed switch on my primary pump I took care of it.

That would be a band aid at best, if it works. Its much easier and correct method to slip in an IFC in the current zone pump or swap out the ball valve flanges with one that has an IFC, like the grundfos flange valve kit to eliminate ghost flow.