Heating Help

Whatcha Think?

I took out a oil Hb smith (on the right/red) and put in a Burnham wall hung gas. I love learning, and positive feedback, if you have any please drop me a line. Thanks.

Won't that gravity feed?

I"m an oil tech (pretty new) but what is stopping any gravity feeding of water and keeping zones from over heating? I do not see any flow checks or zone valves. Won't water feed right past those circulators? I'm not familiar with them, 99% of my dealings are with Taco 007.

IFC

Oilsbetter, Those are most likely internal flow check circulators. They have the flowchecks built right into the pump. Tacos have that as well.

IFC,s FYI....

The check valves that come on these pumps have a real weak spring on them. They were not intended as a flow check, but rather as a back flow check. So, if you have two opposing pumps, and only one will ever be on at a given time, then it works to stop back flow through the off pump. But if you are depending on the check to stop gravity flow, good luck...

ME

Am I just lucky?

"The check valves that come on these pumps have a real weak spring..."

My system has two zones that use Taco 007-IFC circulators to run them. In that part of the system there is no Flow Check valve. Both circulators can run at once, but that is not usual. Now if one runs, the IFC valve prevents backflow through the other zone., but the spring, as you say, is so weak I doubt it would stop gravity flow. Yet I do not observer any.

Now one zone is much lower than the top of the boiler, where the near-boiler plumbing is located (including all the circulators), and there is a drop of at least 5 feet to get to where that zone is. So that may keep gravity flow out of that zone (the hot water would have to flow down, and the returning colder water would have to flow up).

The other zone is about 4 feet above, though, and I notice no gravity flow there either. Am I just lucky about that? Or does the fact that there is over 64 feet of horizontal 1/2" copper tubing in that circuit (not counting 28 feet of 3/4" Slant/Fin baseboard) keep there from being much gravity flow up there?

Gravity potentials...

Height is the biggest dictator of gravity flow potentials, followed closely by restricted piping circuits and water temperatures. Remember, hot water will not flow down hill by itself. Cold water will in fact settle, thereby forcing hot water to rise.

The higher the system height above the heat source, the greater the potential for gravity circulation.

Many times, gravity circulation is occurring, but not at a rate that it's presence is felt. Just guessing, but if you went to the first baseboard in the upper floor loop after the DHW function has just finished a cycle, you will feel some warmth at that point.

I have had situations where I had a swing check on the supply and the return, and I still got gravity circ. I ended up having to install a spring check on the supply and return to negate it.

Gravity does some strange things, including flowing through just one pipe, up the center, and down the outside edges.

There is a method known as "trapping", that theoretically should stop the gravity circ potential, but I have seen situations where they didn't work. It just depends on all the potentials at work, including but not limited to height, water temp on the supply, and water temp on the return and pipe restrictions.

I had a 12 story building once that had closed loop glycolized solar collectors on the roof, an unpressurised 1,000 gallon storage tank in the basement with immersed coils in the storage tank for DHW preheat, a shell and tube HXer between the solar closed loop and the water in the unpressurised storage tank, and I kept freezing and breaking the 1/4" mini tubes in the heat exchanger bundle, IN THE SUMMER!

The closed loop portion had a 3" swing check on it that should have stopped any reverse thermosiphoning from occurring. It wasn't reverse thermosiphoning, it was FORWARD thermosiphoning, and it was doing it at such a subtle rate that it was bringing glycol back down to the heat exchanger at a temperature low enough to freeze and burst the 1/4" tubes in the HXer. The collectors were giving up the heat due to night sky re-radiation, causing the glycol to super cool below freezing even though the ambient had not dropped below freezing that night...

The fix was easy enough. I drilled a hole in the water line coming out of the HXer which was mounted on top of the solar storage tank, and installed a 1/4" copper vent tube so that when the solar storage tank pump was off, all water drained out of the HXer and back into the tank, breaking my thermal connection. The storage tank water pump was a base mounted pump located at floor level, so it was always wetted and had a good 4' of NPSH. I suspect that the collector loop still forward thermosiphoned due to height considerations, but there was nothing left for it to freeze.

Just when you think you've seen everything there is to see, mother nature pops up and shows you something new.

ME

Just guessing,

I guess I cannot test that, because there is a real Taco FloCheck valve isolating the DHW part of the system from the rest, and it seems to work. No spring at all, just a heavy weighted disk.

Since the downstairs zone will never get above 120F and the upstairs has fin-tube baseboard, perhaps the gravity flow, if any, will put too low a temperature up there, as you suggest. I sure have no trouble feeling 110F hot water in there when that zone is actually calling for heat.

yes they are internl flow checks

Grundfos, is the name brand. At first I did not like them because I thought they would get clogged easily, but I don't overlap my teflon tape over the threads when and if I use it. Just starting out you picked a good spot to learn from. I'm 12 years in the Buisness, and my first license was my oil burner tech, I took a class in Woburn, called peterson. It was hands on, which was good. But Most stuff comes from experience. Good luck, and when you do cleaning or tune ups let the vacuum do most the breathing.

looks nice

A couple things to think about:

Ball valves and unions for the boiler.  Having them will aid in service for-sure.

Ball valve between the system and the outlet side of the water pressure regulator.  Those things can fail in time, isolation is needed so drainage of the system can be avoided.

I like to add an additional ball valve for isolation of the expansion tank as well.

I could not make out the name on the wall hung boiler

Does that have an internal circulator on it? If not how is the water flowing through the heat exchanger?

Burnham Freedom CM is the name

Charlie it's one from a contact I made at a gas networks, (seminar/dinner in a nice hotel) Nancy Curtain or Vinny best are a big help. The circ is there, maybe the pics I loaded did not show it. I did cheese on the check valve. And these pics were taken before I installed the condensate pump.

gray pump

gray wall, the camo look . I see it now thanks.

Forgot to mention...

Nice pipe work!

Don't forget the neutralizer, and welcome to The Wall.

ME

Al

I got the basics down in my hydronics. I don't do alot of installs i'm mainly only doing service calls. I went to school at Old Colony in Brockton. They basically teach you just enough to get your license. I've learned alot the 6 months I've been in the field. Still alot more to go though. I"m up for it.
I know of the site because we watched alot of Dan's videos in class. My teacher is a big fan.

Words to live by if you ever choose to go on your own

If you can't make money from your family and friends, you won't be able to on any money from anyone else.

Well I can not make money from my family

I do not work for family as a rule. Long stories but it simply does not work for me.

Working for Family

Working in this industry you will receive calls from family and friends that is because they need you ... With me I needed set grounds .... There are givers and takers in this World .. With I being more of a giver I learned to beware ... Tip : If with in 10 minutes of meeting someone and they ask you for something , anything .... Beware !

And as the old saying goes ... "No good deed goes unpunished "...

near boiler piping

Question or comment here.  I was under the impression that the manufacturers of mod/con boilers frowned on the practice of installing black pipe instead of copper for near boiler piping as it end up clogging the heat exchangers over time.  I know when piping to a system that has existing black piping that it is reccommended to install a line strainer on the return manifold to prevent heat exchangers from clogging up.  Opinions?

Near boiler plumbing on mod|con...

Since I am not a professional, I cannot say how near-boiler plumbing should be done, but I can say what my contractor did do. The contractor did follow the instructions of the Installation manual, for one thing. And that manual does not say to use only copper pipe, nor does it say to use a strainer in the return (or anywhere else).

This is a W-M Ultra 3 80K BTU/hr (input) boiler with an aluminum heat exchanger. From the heat exchanger, steel pipe goes to the top (and can also go to the bottom) of the boiler. I would not call it black pipe, nor is it galvanized; it is fairly shiny, but not polished. Similarly, the gas input pipe is the same kind of steel. It looks a little like stainless, but may not be. From the gas meter to the boiler is what is clearly black pipe (except for a piece of flex).

Now what the contractor did is run steel pipe that may be called black pipe, but it is by no means as black as the gas pipe, nor is it as shiny as the stuff inside the boiler. This pipe goes to the pressure relief valve on the supply line, through the Flow Check valve . From there it switches to copper and goes to one of the closely spaced Ts of the P-S piping. The supply and return are one-inch. W-M say the rest of the primary piping must be at least one inch, and my contractor used 1 1/4 inch. He said it works better. There are quite a few ball valves and purge valves that I won't bother with. These are brass. The secondary side is all copper or brass except the two Taco 007-IFC circulators.

On the return side, it goes to the LWCO, and switches to copper and goes to the boiler circulator and up to the other of the closely spaced Ts.

I specifically asked about a strainer, and they said it was not a good idea because if it clogged, the heat exchanger could melt due to low flow. I am not sure of that, because the controls check the temperatures of the heat exchanger and if they exceed 200F are supposed to shut down the boiler. Or they could use a different type of strainer, such as

http://www.caleffi.us/caleffi/en_IT/Site/Products/Catalogue/args/sezione/Family290_dirt_separator/path/5~5462~5462-details/include/~applications~catalog~serie.jsp/index.sdo

I do not know what one of these would cost, but compared with the cost of the whole job, it could not be much.

Dumb question

The red boiler that was removed looks like a steam set up (gage glass, LWCO), whereas the replacement looks like hot water (circulators, expansion tank). No one else mentioned that so I must be missing something here?

Good eye...

I don't usually pay a LOT of attention to the pictures, but you are correct, that was obviously a steam system.

Surprised Steamhead didn't catch that one. :-)

ME

Actually, I did

but waited for someone else to.

The condition of that Smith 8 steamer says it all. Smith Series 8 boilers are H-E-A-V-Y, and it takes a lot of abuse and neglect to kill one. That boiler was seriously neglected. And if the new one is neglected it will fail too, and probably much more quickly, and will use a lot more gas along the way. Ask Mark about the no-maintenance trial he did on his. What an eye-opener.

Then the owner will get his lawyer involved, because he spent all that money for something that didn't last and wasn't as efficient as promised.  Never mind that he didn't follow the maintenance schedule- the gas company has always said gas equipment doesn't need maintenance, and they're never wrong, because they're the gas company >:( 

Why didn't you just put in a new steamer with a probe-type LWCO, which is much more reliable than the float-type that was on the old Smith?