flow checks

tm

Great replies, thanks. Now I understand why some use them while others don't feel the absolute need.

tm

This is for a hot water boiler job:
Ok - why do I need flow checks on both the supply and the return? I will have 4 zones, and I am using 4 circulators (pumping away). Do I REALLY need 8 flow checks or can I do without the ones going into my return manifold? Also where is the best place to put my purge valves - at each return near the manifold? Thanks!!

Ragu

No Offense Tom, But....

The type of questions that you have been asking here indicate that you probably should not be doing this job by yourself. Perhaps it would be wise to hire a Pro, and assist in the installation. Too much can go wrong if you're not on top of your game. I hope you hear what I'm saying. Good luck.

Unknown

We use flowchecks

on the supply pipe only . Very , very rarely do we have heat migration problems .

You can put the purge valves at each return near the manifold . Makes it real easy to drain an individual zone down without letting the pressure drop in the other zones .

tm

Ragu,
No offence taken, but I would rather do it myself. I thought the name of this site was HEATINGHELP.COM. I am looking for help. If you already know it all and don't want to help others then why are you on this site??I am a good mechanic, I am just not sure of equipment placement and need. I don't really care if my questions seem stupid to you or if I seem unqualified to you. I will take the time to get all my questions answered by those kind enough to help me. I will develope a plan to do the job right. Then I will do the job gaining alot of knowledge along the way, and also feel a great deal of satisfaction. I will have a better understanding of how the equuipment in my home works. If I need a pro to check me out and help with start-up to feel more comfortable then that is what I will do.

JB_8

Questions

The stupidest question of all is the one not asked. Keep on asking and asking you will never be stupid.

Timco

I have 3 zones, and needed 6 checks (center spring, silent check). I had ghosting with only 3 on the supply side. My local B&G dealer had them....they work in vertical or horizontal position. Most are horizontal only, depending on the type. A swing check can be vertical on the send, but must be horizontal on the return. They want to be 6-12 " from the pump or a 90, to eliminate rattle. Taco checks need to be horizontal. Remember, heat rises.

T

Wayco Wayne_2

Flow checks on both

supply and return is how we do it because there is the possibilty of single pipe ghost flow. monolaminar flow is the technical term for it. It is possible for the hot water to go up the sides of the tubing and the cold water to drop down the middle. I use a circulator with a flow check in the discharge and a B&G spring check or flow control valve on the return all the time. Cheaper in the long run to prevent it than to have to come back and fix it. WW

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Ragu

Tom

You are right; this place is for heating help. Sorry.
Wayne's post taught me that double checks are not all that rare. I personally haven't had a problem with heat migration yet, but some folks around here had a really bad time with sweatcheks last year, and went to double checks. I've been using circs with integral checks for about 2 years and so far so good.

hr

The issue with ghost flow

or heat migration is catching it in the act. It can be a very slow and subtle issue and may or may not add to control or fuel consumption problems.

Unless it is causing overheating or excessive indirect temperatures it is often un noticed.

Be that as it may the steps to eliminate it are worth the cost and effort. The Grundfos Super Brutes cost the same, or less, than regular non check circulators. Same for other brands of intergral check circs. So this handles one side by default. A flow check or spring check is also a very inexpensive device to install.

So my question would be why not? It is a lot easier to install these on the front end that a return call back. That is IF the ghost is ever discovered

hot rod

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Joe Mattiello

Perhaps you can use the Taco, 00 series with the integral flow check valve which will save you money,time, and give you better performance. Using 2 checks isn’t always necessary. If the pressure drop across closely spaced tee’s is small enough, 1 may suffice. If you experience ghost flow you will have to add the second check.


Taco, Inc.
Joe Mattiello
Technical Service Technician
joemat@taco-hvac.com
401-942-8000 X 484
www.taco-hvac.com

Cosmo_3

Please don't be angry

We here on the wall, at least the guys who do this for a living, have seen too many diy goofups that cause harm to the occupants.

You will probably only need flow checks on the returns, or supply. I prefer buying circs w/ integral flowchecks, but that does not mean that any other flowcheck will not work. You must remember to visually see the check as you manipulate the adjustment screw (before piping the check in) so that you know how many turns will just seat the valve, yet allow the valve to open fully during flow condition. A pro can help you now before you buy the materials because he can determine what size circs, fittings, and pipe you will need to get enough GPM out to your heat emitters. An experianced pro can also see the job and recommend supply and return flow checks on short, low resistence runs to heat emitters that may be more prone to gravity flow than others. He can also do a spot check of the system to look for obvious CO problems, etc.

For purging, one way is to add a valve/purge valve combo on every return and manipulate these one by one to remove air. Or if you buy one of Dan's books, I think it is titled "Pumping away, and other cool piping options" he has excellent piping diagrams that show you how to pipe your system and only have one purge valve to purge the whole system, as long as it is not prim/secondary piping. This book also takes you step by step to show you the science (in layman's terms) behind why we pipe heating systems the way we do.

I can respect your decision to ask questions, and the only dumb question is one that is repeated. Unfortunately (in my opinion) many times a few parts and pipes can be thrown together and you can get hydronic heat to work, but it doesn't mean it is fuel efficient, will provide a long trouble free service life, or keep you as comfortable as doing it the right way. Good luck on your endeavor


Cosmo Valavanis

Dependable P.H.C. Inc.