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Any issues with this near boiler piping diagram?

MalMal Posts: 9Member

First post, but I've been reading a lot.

We're putting in an addition and adding a boiler and fin/tube.  Currently the house has electric heat but is 90% heated with a fireplace insert.  The square footage after the addition will be 1500.  The heat loss was calculated for the rooms and the whole house and it comes up at around 53k btu. 

The house will be piped with 3/4 fostapex.  All the near boiler stuff is copper.

I need to know if there are any glaring issues with this diagram.    It's not showing drains or isolation valves but there will be enough to isolate the boiler, the pumps and each zone.  There are also Tees going in for  DHW but that's not going in now, it may in the future.

The one issue I see if the Grundfos pump in the manual is recommended as Taco008 equiv of Grundfos 15-42...the 15-48 is a three speed, I guess because the boiler loop is so small it can be run at lower wattage?

How badly will this short cycle if at all?   The boiler only modulates down to 30k.

 Crown is the best supported boiler mfg in my area(NW NJ).  They say it has good customer support and the local plumbing house has parts and all the plumbers in the area know these.

Nothing is purchased yet, it's still in the design phase.  Suggestions welcome.


***I've updated the plan based on the suggestions in the thread.  Revision 1.


  • Mark EathertonMark Eatherton Posts: 5,843Member
    edited April 2012

    What you've drawn there is NOT RECOMMENDED by the manufacturer, even though they show it in their manual.

    You have two pumps of different sizes in series, which is a definite no no. I am assuming (hoping really) that you intended to draw this as a primary/secondary system, as suggested and preferred by the manufacturer.

    Is it your intent to have 3 space heating zones, or 2 space heating zones with one DHW zone through zone valves?

    Kudos to you for at least educating yourself BEFORE you start soldering pipes. Most people show up here AFTER they've already messed it up, and it is a LOT harder to fix at that point.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • meplumbermeplumber Posts: 678Member
    He has hydronic separation.

    Mark. The Taco HYSEP-100 is true hydronic separation. Like the Low loss header.
  • Jean-David BeyerJean-David Beyer Posts: 2,632Member
    What is that swing check for?

    If you are going to pipe the future indirect across the supply and return of the boiler, with its own circulator, you will no doubt want suitable flow-check valves in there, but I do not know if a swing-check will do the job. (I am not a heating professional.)
  • MalMal Posts: 9Member
    edited April 2012
    Not in a series

    ---What you've drawn there is NOT RECOMMENDED by the manufacturer, even though they show it in their manual.

    You have two pumps of different sizes in series, which is a definite no no---

    The Taco Hydraulic Separator is in place of closely spaced tees.  The pumps are not in a series. 

    This is 3 heating zones.  The DHW stubs are not shown.
  • MalMal Posts: 9Member
    Flow check it is.

    --- you will no doubt want suitable flow-check valves--

    Good catch, thank you.  I'll put a Flow check in instead of a swing check.
  • Mark EathertonMark Eatherton Posts: 5,843Member
    I see, said the blind man...

    as he walked into The Wall... :-0 Thanks for pointing that out little me ;-)

    I completely missed that. I thought it was just an air separator, not a LLH. Guess I'd better start using both eyes from here on out...

    My bad. Only question I'd have is how do you intend to do the DHW system? If you follow the manufacturers recommendations, it will work just fine. Watch your check valves.

    Carry on...

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • MalMal Posts: 9Member

    The idea right now is to put a Tee-Stub out for DHW after the check on the hotwater supply to DHW tank, and to have the Tee-Stub after the boiler loop circulator for the DHW return.  Obviously it needs it's own circulator.   My goal here is to wait until the current electric hot water here dies and make the decision then.  At that point it's just plumbing in the new tank and running a circ and copper off of the stubs.  There are pluses(cheaper, essentially endless hot water) and minuses(boiler runs year round, boiler goes, no hw) and right now with the huge amount were spending on the house, we're going to wait on that one.

    I know there are rules about 12x pipe diameters in front of a circulator inlet to prevent turbulence, and 12x in front of a check to prevent noise, so that will come into play as to where everything goes when it gets laid out in the room that doesn't exist yet.  I'm trying to get the theory right and as close as I can to acceptable then work within those as the limits to the space.
  • meplumbermeplumber Posts: 678Member
    No Problem Mark.

    It happens to me all the time.

    I don't like the flow check on the boiler side of the LLH. I only use a check valve in that position when I am piping several mod/cons into an arrangement.
  • gennadygennady Posts: 758Member
    flow check

    you do not need flow check on low mass boilers. especially on boiler side of LLH. Also i would move expansion tank to the bottom of low loss header.
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
  • Jean-David BeyerJean-David Beyer Posts: 2,632Member
    How could he do that?

    I am not a heating professional, but I do not see how he could move the expansion tank to the bottom of that low loss header. The bottom connection is the blow-down valve for the dirt trap element of the low loss header, and I cannot imagine it would do the expansion tank any good for the dirt to be draining into it.
  • MalMal Posts: 9Member
    I had the same question

    If the bottom of the taco Hsep-100 is a debris removal port, won't the debris end up in the expansion tank?  This is an all new system, so there really shouldn't be much debris, but no sense in clogging it up.

    Also, the included mounting brackets of this hydraulic separator mount it close to the wall.  It would have to be spaced out for the tank to fit.

    The Bimini Buddy ( ) from Crown suggests the expansion tank be mounted at the bottom of the low loss header, but for heat only version BB100H, that thing ends up being about $700 when you add the air scoop.  The Taco Hsep-100 is around $300 with the air scoop.   If there is a better LLH for 300-400 dollars, i'd be open to using it.
  • gennadygennady Posts: 758Member
    edited April 2012
    exp tank connection

    i do it the way it shown on the picture, If there dirt it goes down not to expansion tank . actually there is no flow in the pipe between exp tank and connection tee. it is dead end pipe.

    Also, after flushing, chemical cleaning of the system and adding water conditioner, there is not much dirt left in the system.
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
  • MalMal Posts: 9Member
    Ok, the flow check goes.

    I'll take the flow check out.  I only put it there because the manual shows one, but now that I look at the drawing again, they have a swing check after the circulator so I had it in the wrong spot anyway.

     The pump that I think makes more sense than the suggested Taco008/Grundfos15-42 is the Grundfos15-58FC.   It's got an integrated flow check.   This entire boiler loop is going to be about 12 feet of piping or less, I think all these  pumps are too big but the 15-58 ( can at least be switched down to low.    After looking at all the GPM curves of these pumps, even with 5 feet of head on low speed, it's pumping 5gpm which is more than the minimum req of 4gpm.  On setting 2, it's 10gpm, which is very close and slightly less than the pump curve on the 15-42.
  • MalMal Posts: 9Member
    That makes sense, thanks!

    I get it now.  I'm not a plumber and it shows.    Tee off the pipe coming off the bottom of the LLH, straight down to a hose bib/debris/drain port and tee off to the exp tank.

    Thanks!  Exactly what I'm looking for.
  • MalMal Posts: 9Member
    I updated the drawing

    I updated the drawing in the first post.

    I removed the check, moved the exp tank under the LLH and added the Indirect Water Heater stubs for future domestic hot water.

    Obviously the IWH needs a check on the return if it's ever plumbed in, but not showing that now.

    There will be isolation full flow ball valves on the house side of the unions joining the boiler, before and after each pump, one on the supply side of each zone.  Should I isolate each zone valve or should I just put one on the return side of the zone valve?

    I know there's supposed to be a safety relief valve right at the boiler on the supply side.

    I guess my only question left, is where should the gauges go?  
  • scott markle_2scott markle_2 Posts: 611Member
    free watt


    Followed your link to see what kind of work you were up to. You have good informative website.

    It may be a bit off topic but I have a question about free watt. Do you think it's reasonable that this equipment should qualify for net metering? As I see it the bulk of the average heating load (and thus electrical generation) is at night. Currently the grid has an excess of generating capacity at night so while you can get paid for power generated it's unlikely that these electrons end up doing any useful work. I recognize that this type of heat recovery has obvious merits, I also see that it would have no commercial viability (for residential installations) with out favorable net metering laws.
  • Tim PotterTim Potter Posts: 247Member
    Short cycling part of your question

    Now would be a good time to substitute a BoilerBuddy indirect or equivalent for the Taco HYSEP. On my system, I can't tell you how satisfied I am with my BB upgrade. You absolutely will NOT short cycle. By looking at your zones, I think you would be subject to short cycling a lot when the heat demand is low. With adding a buffer, your Boiler will have long on & off times even in the shoulder sesason.

    You could kill 2 birds with 1 stone by adopting the Turbomax reverse indirect as your buffer & IWH all in 1. lots more money, but cry once, then you are done. Indirects don't loose much heat, (1/2*/hour), so the boiler would run way less than the electric you have now.

    Just throwing it out for your consideration,

    Hope all goes well,

    Winter Park, CO & Lenexa, KS
  • MalMal Posts: 9Member
    Looked at the Boiler Buddy

    I got a quote for the 30 gallon BB a few weeks ago and I'm certain it will solve any short cycle issue, it also seems like it's counter productive to a condensing boiler.  I wish the boiler would modulate down to 20k then I wouldn't be too concerned since I'm quite sure it's that the biggest zone will be calling for heat if the boiler is working at all.    At the price quoted, I'd be tempted to go buy a crappy HD tank and pipe it in series just for the added mass.

    I also think in the shoulder seasons, we'll just use the fireplace insert anyway.  The way the house is configured the main downstairs  and the lofted master bedroom will get heat from the insert(72kbtu).  I'll keep an eye on it and change the piping if it's going nuts.   We're stretched for budget right now.  There is no cry once, there's just simply can't buy it.   Anyone see "Mr Blanding's builds his dream house"?  I feel like Mr Blanding.
  • gennadygennady Posts: 758Member
    freewatt system

    What Freewatt does , is supplying electricity for 1/2 price and heating and hot water for free most of the time. net metering applies here to the extent, that you do not want sell electricity back to utility, all you want is to keep electric meter around 0. during electrical consumption house gets electricity from Freewatt and grid, so meter rotates to positive direction, at night, when Freewatt generates more than house consumes, it send power back to grid, and meter rotates to negative direction, decreasing electrical meter reading.
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
  • Tim PotterTim Potter Posts: 247Member
    Buffer & ModCon

    Actually, I've read on the forum here from "those in the know", that a buffer works quite nicely with a ModCon to streach those burn times out to Low & Slow for great economy. If ModCons were 100 to 1 turndown, then not needed for sure.

    Watch out on the home depot home brew buffer, it can & has be done, but I've heard its tricky to maintain proper flow through the boiler, its very important, & being able to get enough flow fhrough the secondary with 3/4 tapings.

    Winter Park, CO & Lenexa, KS
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