Uneven heating in two mains - incorrect piping? i posted pics - please help!

sean_b

i see!

Thank you! 



  I am even confusing myself here - ha!!!



Just so that I am straight on this - in summary re: the piping of the HW tank --- what do you guys feel is the proper way to do it (both involve getting the return out of the skim port)? 



a) Use the front left port as the source of HW for the tank, and then have the return water go into the rear boiler return pipe (the current source)?

or

b) leave source like it is, and then lead the HW tank return down from the skim port to the port on the lower front left of the boiler?

Dave in QCA

Manufacturer's Specification Apply

It should only be connected according to the manufacturer's recommendations.  I am 99% sure that they will not approve the way it is currently connected. 



Here is a link to Weil-McLain's manual on their similar product. 



  http://weil-mclain.com/en/multimedia-library/pdf/weil-mclain-pdf/products/water-heaters/indirect-fired-water-heater/indirec_fired_water_heater_series3_plus_indirect_fired_water_heaters_manual.pdf



  You will note that the boiler taps that are used are specified to be "below the water line".  Also, and issue when pumping any loop off of a steam boiler, is the fact that water is often at the boiling temperature.  Running this hot of water through a pump can cause flashing, and cavitation, which will wear your pump out prematurely.  So, in this literature, you will see a crossover line that is used to temper the boiler whater before it gets to the pump.  Instructions and explanations are included. 



What is the make of your water tank?

sean_b

re: Manufacturer's Specification Apply

The water tank is a mega-stor - and I couldnt really determine from their install manual how it should be connected to my boiler. 

I am not sure if pdf's I have tried to attach show up so here is a link to their manual



http://www.crownboiler.com/manuals/content/Indirect_Water_Heaters/MegaStor%2008-10%20R-5.pdf



 

Dave in QCA

doesn't show steam

From my quick skimming of the manual, I can't see that they make any recommendation on how to connect to a steam boiler.  You might want to contact Crown / megastore and see if it is even approved for that application, and if so, what their piping requirement would be.

Of course, exactly how it is connected to you Smith boiler is going to be determined by Smith. 

sean_b

right...

thanks so much for taking a look Dave!



i'll wait and see what the Smith rep comes back with i guess then go from there...



Correct me if I am wrong, but as far as wet steam production goes, is this issue less critical than my disgusting boiler water (for the time being)?  Our hot water demands are very low right now, just a couple showers in the a.m. and occasional washing dishes/dishwasher.  It seems that hours can go by before the HW tank wants a little heat up so hopefully its contribution to wet steam is not that bad.

sean_b

skimming and sediment

i know this question might be best as a separate thread, but i am unsure of some terminology and things might be safest for me with a picture!



since the boiler is being skimmed today, i was wondering - is draining out a little bit of sediment (maybe a gal. of water or so at a time) something I can do myself over the next few days/weeks?  My thinking is that maybe when the system is cool, sediment might fall down to the bottom and i can get a little out at a time till its looking pretty clear.



If so - where would be the best place to do it from?  There is a valve near the floor directly under the CW makup feeder (on the return pipe- red handle with red arrow pointing to it).  There is also that port on the front bottom left of the boiler that the tech used to lower the water to take out the LWC probe.  The water that came out there was bad too....  Is this something I can do using either of these?  Or is there a better one?  Or should I just not even attempt this?

Dave in QCA

cleaning

that drain will only flush you wet return, not a bad thing to do.  Your drain at the front corner, is essentiall the mud leg.  A good place to flush the stuff that falls to the bottom of the boiler.  Most of the crud in a new boiler is oily, and is floating near the water line.  Thus, skimming is the only way to get it all out.  It will take many times over the course of several day.

search skimming on the wall here.

Also, see what the manual says about it.

sean_b

thanks

thanks for all your help this week guys!  I really appreciate it!



Dave, i have been reading up a bunch about skimming - not confident to try it yet though and need do some more research for sure.  i wish i could have been there today when the tech came by to skim the thing - would have liked to seen it done first hand at least once....  i dont have a problem doing it myself as much as needed, but gettign the installers there a bunch more times seems daunting!



have a good weekend!

Steve_175

Skimming Port

Looks like your skimming port is on the front of the boiler just below and to the right of the pressure gauge. It has a square headed plug in it. You can either screw in a length of pipe into it or a fitting that will accept a garden hose, like on the mud leg.



You want to skim when the boiler is turned off and cool. Open up the skimming port and SLOWLY fill the boiler with fresh water, just a trickle. Do this until all the water runs clear and then do it a bit more. Fresh water is pushing the dirty water up and out the port. I spent several hours over the course of an afternoon swapping 5gl buckets until it was running clean for a couple of buckets worth.



After I cleaned my new boiler it made a big differnce in the performance of the system. It also really helps in producing dry steam. This will help a lot with your spitting vents as others have said.

sean_b

Update - Now my problem is reversed - how can i properly balance mains

Thank you everyone for all the help and advice!   I am hoping you can help me out on how i might go about actually balancing the vent rates of the two mains now. 



Friday the installer came back and skimmed the system again.  And in the meantime he had been talking to someone he knows also re: the balancing issues.  He is experimenting a bit trying to figure this out I guess.  



in summary (as a reminder) my problem was initially that the front main (which is first to receive steam coming up out of the riser from the boiler) was venting super hard, and loud with undersized ventrite #35 on it, it would heat up and close fairly fast and a ton of heat would go to all the front radiators.  However, the rear main was taking FOREVER to heat and vent close (also with a ventrite #35), and some radiators never even heating up (the 2nd fl, furthest radiator).   I put on new Gorton #1's for both of the mains but still didnt really fix the issue with the uneven times to heat - just vented the mains faster (so likely an improvement in fuel savings for sure...).



but Friday the installer had removed the front main vent all together  and put a cap temporarily.  this actually resulted in a little bit of an improvement.  the front rads were set low though (like 3.5 and 4 for the most part) so of course it took a while to heat them all up - especially the further rads - but opening them wider where needed  helped a little.  The rear main however - the gorton still on it - vented properly for once!  It heated up and closed in no time, all rads, even the furthest problem rad heated up incredibly well.  So now my problem is reversed - i am getting great heat in the rear and not the front!  This is somewhat good news also though, because maybe now I can safely assume that water in the rear main and/or slow/clogged returns can be eliminated.



So anyway, i monitored how it all worked for Saturday to report back to the installers today.  then Sunday, i took the cap off, and put a ventrite #33 back on on the front main.  Of course this was a nice improvement over no vent (i tried to make sure no rad vent was set too high though so it didnt outvent the main #33 - but still took a bit to close)...  for some reason it didnt cross my mind that the two mains might benefit from being vented at two different rates.... seems logical in hindsight!



My question is, is there a better way to balance out these mains than trial and error?  do they make anything to read the pressure on the tapping and go from there?  Or should I just try different configurations - for example i was thinking of trying next, hooking up both gorton #1's on the rear main, and hooking up both ventrites on the front (because I already own all these vents!).  But that is the same ratio I have now (which is 0.11/0.33 cfm front to rear) just scaled up by a factor of 2.  If thats no good, should i pick up another gorton #1 for the front?  maybe 1 gorton #1 on the front and two on the rear?  or maybe 2 ventrites on front and 1 gorton on rear for a .22/.33 cfm ratio.        I.e. is there a way to figure out what the best ratio should be? 



related to that, the vents would be hooked up candelabra style   - is this ok?  I cant seem to find out what the airflow rate is the for 1/2" pipe that is tapped into the main - would two gorton #1's at 0.33cfm each (0.66cfm total) exceed the capacity for a 1/2" pipe anyway? 



OR am i just barking up the wrong tree, and differences between the front and rear mains (pressure, length, # of rads, etc.)  dont matter - just  vent both as fast as humanly possible and forget everything else?  by the way, if this were true then why do they make all these different main vents with different cfm rates etc?  Why not just make one kind that is the same diameter and airflow as your main pipe (size of an open pipe) ?   



Any more advice you might be willing to offer would be greatly appreciated!

Dave in QCA

Main Venting

It sounds like the issues due to water coming up into your main has been corrected by skimming....



So, regarding venting. 

You cannot have too much main venting.  The whole purpose is to let the air flow freely out of the main vents as the steam is coming down the pipe, so that its tendency to flow into the radiators before the mains are fully filled with steam will be avoided.  Once steam starts to flow into a radiator, it will slow down the movement of the steam down the main(s).    It is desirable to vent the mains in 2-3 minutes.  I forget the size of your pipe, and the total length, but here are some numbers that will let you figure what your min venting should be.  2" pipe has .023 Cubic feet per linear foot.  2 1/2" pipe has .03 cf/lf, 3" pipe has .053 cu ft/lf.



The venting capacity of a piece of 1/2" pipe is 2.6 CFM at 1 oz of pressure.  I suspect that your Gorton #1s may still be a bit on the small size, but you can measure and do the math.



The other important part of the equation is keeping your radiators slow.  There is a tremendous difference on those Hoffman 1A vents at the low end of the scale.  Also, there is usually some sloppy play in the fitting of the adjusting ring and the center screw.  Therefore, while you have a vent set at 2, if you wiggle it, it may actually vent much faster, or slower, depending on how it is centered.



As a point to proceed, I would do some measureing.  See how much volume you have in your steam mains.  Divide by 3, and that is the venting that is required in cfm to vent your mains in 3 minutes.  If you come up with a fractional amount err on the side of excess venting.  Keep in mind that if you are venting through a 1/2" pipe, 2 Gorton #2s is the maximum that the 1/2" can vent.  3 Gorton #2s on a half inch pipe will still only vent about the amount as 2 would.



Next, turn all of your Hoffman 1A vents down to 2.  See if your mains both heat up in close (30-40 seconds) to each other.  If they are not perfectly balanced, as one main vent station closes, the steam will quickly push down the other main until it closes, unless your radiator vents are venting an amount that allows your radiators to go into competition for that steam.  If the radiators are venting too fast, they will win, and it will take forever for the steam to get down the slower main.  As your mains are venting, you ideally see no steam coming into your radiators.  If you are beggining to get steam into any radiator before the mains are fully steamed, turn that radiator down to 1. 



The most important part of the balancing is between the main vents and rad vents.  Mains should be FAST!  Radiators should be SLOW!  This balance is far more important than balancing the 2 mains.  If one main fills 30 seconds sooner than the other one, the second one will catch up very quickly and completely.  But, only as long as your radiators are SLOW, and of course, you are getting dry steam and not throwing water up into your steam mains.

sean_b

re: main venting

Dave thank you so much for all of the detail!!!!     i will figure the math when i get home tonight and measure total lengths.



i need to lower my rad vents for sure - and being new to the concepts of steam heat, i have a hard time reconciling the idea of slowing down the rads to make them work better - i always tend to think i want to turn them up wanting the most heat as fast as possible so the system doesnt run so long and burn all that fuel!  I have gone through an OBSCENE amount of fuel since the system was put in at the end of Nov.



by venting the rads much slower, thereby speeding up the mains getting filled, can I expect to reduce the amount of time the system has to run to maintain or even raise the temp in the house?  I understand that we want the mains to vent first and close, but does slowing down the radiator, make it take much longer to provide enough heat to satisfy the thermostat?

Dave in QCA

Even out the heating

Understand that even when you lessen the venting on your radiators, the steam is still going to go into them, evenly and equally, if all goes well.  The pressure in your system is still going to be 1 or 2 oz as you are slowly, but evenly heating up your radiators. It is the same amount of steam, and nothing is being wasted on building pressure.  What you are going to do by slowing down the radiators, is you will be directing the steam where to go.  When your radiators are vented to fast, "they" decide where the steam is going to go.  When you let your radiators duke it out in the battle for steam, the one that can suck the hardest wins the battle, and will leave one or more with nothing, at least they will get their steam so late, that it will seem as if it were nothing.

If your house is evenly heated, with no cold spot, no hot spots, it stands to reason that you would burn less fuel.  However, this has been a very cold winter, and you have probably wasted fuel via the fact that parts of your house were over heated and other parts were not getting any heat at all.



Hopefully, it will be better.  My 8,400 sq ft building burned $1,300 worth of natural gas in the month of January.  $1,162 on December.  Wanna trade? 

sean_b

update

my update is (knock on wood)  that everything is working *good*!  i did not think it would ever happen!  Thank you all for all the extra effort you put in for me, all the advice, analyzing my pictures, looking up and posting manuals etc.!



so the boiler was skimmed by the installers last friday, and skimmed again on Monday prior to the arrival of the 4th or 5th snowpocalypse this season.  After Fridays skimming it still seemed to be surging a bit, so i asked them to come back.  but the waterline is *fairly* stable now in that sight glass - moves w/in an inch range or less i'd say and the top of the sight glass is very dry.  most of my problems seem to have been caused by 1) inadequate main vents (only had Ventrite #35 on each) and 2) bad surging, tons of water getting sucked up into the mains, wet steam, etc.  This 1 & 2 combo caused a self-reinforcing feedback loop that it was all stuck in - because i would go an incorrectly adjust rad vents - not knowing when they were all the way open they could even exceed the venting capacity of my main vents! 



now - no gurgling sounds whatsoever - anywhere.  i can no longer hear a single one of my radiator vents venting (used to hear tons of loud uneven whistling and venting), all radiators off both mains heat up now and do so fairly close to at the same time.   even the furthest 2nd floor radiator works!  I thought it might never work again,....



one last question:



I calculated the "theoretical" required main vent capacity i might need to vent the mains within 3 min.  Each main is about 50' and 2" pipe, so call it needing about a 0.38 cfm vent rate to vent my main in 3 min.  I have a Gorton #1 on the front main with a 0.33 cfm vent rate, and then on the rear main i removed the vacuum breaker and put a ventrite #35 (which I already had as an extra) in its place - so the rear main has a Gorton #1 and a ventrite #35 for a total venting rate of 0.44 cfm. 



However, it still takes 7-9 min for both mains to vent (from cold/luke warm start).  Even though the rear main has more capacity it doesnt really vent all that much faster (which is fine...).     Question is, should I bother purchasing 2 more Gorton #1's and putting two of them on each main (~0.66 cfm capacity)?  Or should i just leave well enough alone - its working, and thats a far cry from where i was a week or two ago.  Are the  savings from the extra couple minutes (maybe) going to be big enough to outweigh the extra $50 i'll pay?



i know, ideally i should have just bought the gorton #2's (the huge ones) - but i was in desperation mode then and bought the best i could with what the local supplier had!  so now im invested in the #2's....

Dave in QCA

Success at Last!! Hurray!

Sean, if you want to know if a larger vent would have any effect on how long it takes your mains to vent, try this.  Remove the vents altogether, and fire the boiler.  See how long it takes for steam to arrive.  If there is a significant decrease in the amount of time, I would go aheat and buy 2 Gorton #2s, and I'd put one #2 and one #1 at each vent station.  That would give you 1.43 CFM at each.



If you see no significant difference between an open pipe and your current vents, then it would be a waste of money.



Will it save you money?  Maybe, maybe not.  If you determine that increasing your venting will speed it up, what it will do for your system is to assist in that never ending battle of having the steam arrive at every radiator at the same time.  This is especially noticeable in mild weather when you have short cycles.  Getting even heat in your home will probably save you money because you will be more comfortable and less likely to crank up the thermostat.

Charlie from wmass

Smith still uses 2"

for most headers on the residential side of things.