Piping Issues...IFC check issues...

Bob Forand

They are getting hot on the returns of the zones. I have the supply header about 8 inches above the returns. The return pipes come down from the cieling. They are aproximately 40" high. They are piped with Webstone purge stations. The piping is getting hot quickly. The customer has stated that they can walk up to the baseboard and feel heat being distributed. One of the zones is also the furthest from the boiler room and also it is over the garage.

Kevin, I have it drawn out, I will post it up so you can see how it is piped. I don't have an actual picture of it.

Thanks,

Bob

Bob Forand

Piping issues...IFC flowcheck issues....

I piped up a Buderus G215 oil boiler that has 8 zones of heat. There are 5 high temp and 3 low temp zones and I used Taco pumps with IFC's. The first zone off of the manifold is the DHW and it is a 1" zone with a Taco 007 IFC pump. Whenever that zone is calling three of the other zones are getting heat. I believe it to be flow not migration because of how quickly the heat is going up the return piping. I called Emerson Swan and they said that they are telling guys to doublecheck everything.

That may be all fine and good but I don't know why the system is acting this way. This is a standard supply and return header, pumping away from expansion tank, etc. Has anyone else experienced any issues with IFC's ?

Jean-David Beyer

How big (diameter) are your pipes?

All may be fine and good, but I do not believe it. My setup is a bit like yours, but the boiler is a W-M Ultra 3 that has primary/secondary piping. So imagine two closely spaced Ts with the boiler about 1.5 feet below them. In between, 1" pipe comes off the supply and return from the boiler and goes to the DHW. So this is not part of the primary/secondary piping. On the supply side, above the pipe from the supply to the DHW is a FlowCheck valve On the return side, above the pipe from the DHW is the boiler circulator (standard 007) pumping down. There is an 007IFC in the return path from the DHW to the return side of the boiler. This stuff has been working 24/7 since the system was installed about 2 months ago. When the DHW calls for heat, the boiler puts out 180F water. The DHW has priority, so if it calls for heat, it gets it, and the other zones are cut off (for up to 30 minutes, anyway).

In the secondary part of the piping are two circuits, one supplies 140F to the Slant/Fin upstairs, and one supplies 120F to the radiant tubing in the slab on grade downstairs. Each of these have 007IFC circulators. The heating circuits have been tested and found to work, but it is too hot to run them for extended periods.

In any case, when the DHW is calling for heat, there is slight warming of the return T of the closely spaced Ts. I would say about 10F. The Slant/Fin upstairs shows no trace of heat.

The air eliminator, expansion tank, etc., are just to the right of the right-hand T of the closely spaced Ts (about a foot). After the air eliminator are the connections to the two heating zones, so pumping is away from the closely spaced Ts and the expansion tank.

Most of my pipe is 1" copper, but the pipes nearest the boiler is 1 1/4" because my contractor said these systems work better that way. In John Siegenthaler's book on Hydronic Heating Systems, he suggests a check valve on both the supply and return of each heating zone. From my high school physics, I could not understand why both were required, so I e-mailed him and he said that for 1/2" tubing, two check valves are probably unnecessary; i.e., one would do. But when the tubing is bigger than that, there is a risk that you could set up convection currents in a single tube, so if the check valve were only in the supply side (typical), you could get convection currents in the return side that could transfer unwanted heat. Could this be your problem?

Unknown

Question

Is it just getting hot on the return riser or should I say is the heat starting on the return piping or the outlet of the non calling circulators?

kpc_75

pictures?

it would help a lot for us to see what is there. kpc