Heat gravitating with flow check

Bill Julian

I installed a bunch of Cast Iron BB HW heating boiler using the 007 plastic flow checks. Still getting heat gravitating to the radiation wondering why? Hate to buy a bunch of Taco CXC flow checks if I don't have to. Thanks for any comments.

hot_rod

Could be heat going up and down the return side?
unless something is stuck in those spring checks they seal “bubble tight” It takes .35- 1/2 psi to pop them open

Bill Julian

Yea, I don't know. Might have to drain the system and take them off to check them. Thanks for the insight

hot_rod

I had another hydronics pro tell me around 5- 7 years he ends up replacing a lot of those intergral checks, regardless of the brand.
I don't like them positioned so close to the circ, they see some turbulent conditions. The white ones are not listed for very high temperature. And of course fluid with "chunks" in it is always going to be a challange for any hydronic device.

If they do have debris, adding a Y strainer or dirt separator might be a good move. Any hydronic valve or device with small passageways should be protect somehow.

Install all circs with isolation to make service down the road a simple task, knowing these checks are going to be a service item.

Big Ed_4

Are any of the zones slit into tees ?

Bill Julian

Not sure what you mean, slit into tees, you mean split loop? All zones are one loop cast iron radiation on 4 of the 5 zones.

Big Ed_4

What about the 5th . Split loops will bypass if not piped back into a second tee and a single return ,,,

Bill Julian

I have no split loops in the entire system.

Bill Julian

I have 4 zones with CI BB and 1 zone Copper Fin no split loops all heating fine but the issue with the flow check.

hot_rod

4 zones all zoned with pumps? All need to have adequate flow checks to prevent reverse flow. As well as forward, gravity induced flow.

Bill Julian

All of these zones installed on the return as I have done for decades without issues. All pumps, all 5 zones.
I have the flow checks inside the circs.

Big Ed_4

With large long risers sometimes two checks are needed ... Since you are installing the checks on the return the supply is open to the gravity of hot water . You need to instal a flow check on the supply ..

Bill Julian

got it

hot_rod

Why the pumps on the return? With pumps on supply and checked you might be fine, and also pumping away from the exp tank.

Bill Julian

True. I got a question. Can I use the plastic flow check that is inserted into the 007 on heat pex? In other words, can I install this type of flow check "inline" using the 3/4 orange heat pex and obviously some kind of adapters? Never tried it before if it is even possible? This would be installed INLINE on supply side.

hot_rod

Caleffi has 1/2- 1”

Bill Julian

Thanks!!