2 zones continue to heat even after call

Rex Whitmore

Some background - This is a multiple zone unit, with 4 baseboard loops, 1 DHW, and 2 individual radiant floors. Boiler is set up with a primary loop.
The problem - 2 of the baseboard loops continue to get hot even with the pumps off. The first thing I checked was the check valves (taco 218)- they seem to be clean and free. I disconnected the primary loop pump for a breif time and the zones cooled, but the radiant cooled also. Now I believe there is to much flow somewhere! Every pump on this system is a taco 007 except for taco 010 for the DHW most likely overkill. Is it possible to use a smaller primary loop pump, and still have enough flow for the injection system, keep the boiler from thermal shock, and supply the rest of the system? Or should I be looking into some other type of checks to replace the taco 218s?

Weezbo

are they ifc's?

i would think they would work fine. matter fact we have one of the trianle tubes with three ifc's and havent had a complaint one.

Mellow_2

the way you describe it

It sounds like the mian pump is pulling water through the other zones so I would look at the way they are connected together. Make sure that the flow chek can only be opened by the circ on that zone. I have had cheks leak by and look clean. hope this helps........

MT

just curious if you said there were any zone valves on that system if so they do stick open if honeywell type. Just curious.

Rudy

No zone valves, but I was thinking about replacing the pumps and checks with zone valves since there seems to be enough flow, but I was worried since it hasn't been that cold that if there was a demand for more heat the flow would not be sufficient.

Rudy

Ok! the system is pumping away and the checks are mounted about 6" above the pumps (down stream). The 4 baseboard zones are all plumbed identical. The 2 zones that are working fine are 2nd floor zones. The other 2 are 1st floor and basement zones. It seems like the basement gets the hottest. To me it seems the less head the least resistance /the eazier for the systems main pump to hold the checks open. I'm really looking for the best way to resolve the problem - should I make the system pump smaller or try using spring loaded checks instead of the wieghted type. Or am I missing something altogether

S Davis

Primary Pump

Is your primary pump before or after your high temp takeoffs?

S Davis

Apex Radiant Heating

Rudy

The high temps come right off the loop and return into the loop.

Mellow_2

I think you have a primary/ secondary system. when you turn off the primary circ (main circ) the zones cool then the primary circ is heating the two zones(first floor). The pipes off the main have to be right..... Are the supply and return close together on the main..... can you send a pic or a drawing? This could help alittle.....If the pipes are too far apart the main circ can cause flow in the zones.....