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Harmon HydroFlex 60 Pellet Boiler?

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by velvetfoot, Jan 23, 2012.

  1. maple1

    maple1 Minister of Fire

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    What about a 'modern' cold start oil boiler? They should be designed to be cold most, or at least a lot, of the time?

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  2. velvetfoot

    velvetfoot Minister of Fire

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    I have a cold start oil boiler, but it heats up periodically for dhw, throughout the year.
  3. VT_Bubba

    VT_Bubba Member

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    Good Morning Velvetfoot,

    I also debated the whole concept of using the 2nd boiler as "Extra Mass" in the system. In many ways the heat is not really lost, it's still in the house. In the end, there are two paths to efficiency, Low Mass solutions and Hi Mass solutions, and both have their merits. My Biasi only has 4.5gal of water and System2000 only has like 2.5gal of water, but oil boilers have very fast recovery time. The problem you will have is the slow recovery time on the Hydroflex (Boiler is in shut-down, sitting at 161F and 2 cold heat zones turn-on... Crash.... goes your temp... and now you have to fire the boiler and heat the 2 zones and bring that 2nd boiler up to temp too !). Trust me, the Hydroflex just does not have the BTU balls to lift that load.

    If you want to go that way, then plan on circulating through the 2nd boiler all the time to keep that extra mass at temperature. This would be typical for a boiler with tankless DHW and works great. This is a completely valid approach and my be the better solution for some installations. However, putting the Heat right were you want it ("On the header"), will give you a significantly more efficient solution. I only recommended this approach because you have all of the prerequisites to do the low-mass solution. This really pay's off in the shoulder months and if you think you want to make DHW in the summer (Do you want all of that heat in your basement over the summer ?).

    In the end, you have some design choices to make. These are never clear-cut and you just have to pick a design point and go. The good news is, your existing boiler system lets you do this anyway you want. My proposed solution does require a little more plumbing, but you can expect about 10-15% pellet savings per year and you will use less electricity on the pump too.

    VT_Bubba
  4. velvetfoot

    velvetfoot Minister of Fire

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    VT_Bubba,

    I'm still ruminating, but you used additional an expansion tank and air scoop?
  5. VT_Bubba

    VT_Bubba Member

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    Velvetfoot,

    Yes, I'm suggesting an additional Air Scoop, Expansion Tank, and HyVent on the pellet boiler. This is NOT a hard requirement, but is just good practice, and fairly cheap too. You can also up size the expansion tank on your oil boiler (Go to a T60 Tank). In the end, you really should calculate the total water volume in your system(s) and size your expansion tank(s) appropriately. I have done the calculations a few times and can tell you right now that with the additional water volume from the pellet boiler you will be on the hairy edge with one T30 Expansion tank at high temperatures. Adding the T30 expansion tank and air scoop on the pellet boiler is the easy way to ensure that you will never have problems. Remember, I always design defensively.... Don't cheap out !

    VT_Bubba
  6. velvetfoot

    velvetfoot Minister of Fire

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    The manifolds are actually 1.25" and the pumps are Taco 7.
  7. VT_Bubba

    VT_Bubba Member

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    Velvetfoot,

    All good... The 1.25" manifolds make perfect sense for your installation (BTW: That's what I used too). Per my previous post, you should double check the pipe size on your DHW zone loop (3/4" or 1"), and follow my instructions as appropriate (3/4" = No action required, 1" = Suggest adding "Flo-Control Valve" on DHW zone loop).

    Either buy a new Taco-007 as your pellet circulator, or if it was me I would buy a Taco-00R and put it on my DHW loop and run it on speed-1 (save electricity), and then move the old DHW zone Taco-007 pump to your pellet loop (No - I would buy 2 and keep one at the house as the spare - Remember ==> Eng and can't help myself....). Either way, it should work fine with the 1" pipe on the pellet loop and a Taco-007 pump as the circulator.

    VT_Bubba
  8. velvetfoot

    velvetfoot Minister of Fire

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    The dealer was out this morning to look at my setup. My general feeling at this point is that since these units are sold by traditional fireplace/stove/insert places, they might not have extensive experience in this kind of install.

    I'll try to sketch a flow diagram (with my limited skills) after I digest the info more and post it at some point.
  9. VT_Bubba

    VT_Bubba Member

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    Velvetfoot,

    Your are 100% correct !

    One of the reasons I didn't buy a Harman Pellet Boiler 5yrs ago was the two local Stove/Fireplace shops that carried Harman :
    1) Knew nothing about Boilers and would only sell it to you and point you to a plumber.
    2) Couldn't even have an intelligent discussion with them on the details of the boilers.
    3) Have much higher margins in there business and priced the Harman Boilers at full retail (like they do the pellet stoves).

    Last year I found a semi-local (50 miles away) Heating/Fuel company that started carrying Harman products and could actually talk intelligently on the details of these boilers. They were also willing to price their products to compete in the Heating Business. I'm somewhat reluctant to put these prices on this form, but I negotiated $4,100 for my Hydroflex 60 and $5,400 for the two PB105's they had in stock, last April at the start of the "off-season" and before the price increase (that included the $100 Off Coupon from Harman), and that price also included free delivery of the units right into our basements ! I'm very fortunate to have this local Fuel Company Harman Dealer that rocks ! I have sent them 5 other customers that ALL purchased Harman Products from them (I try to be a very loyal customer for businesses that treat me right !).

    My message to the forum is, try to find a Heating / Fuel company that is also a Harman Dealer as most of the stove shops are expensive and don't know anything about boilers.

    VT_Bubba
  10. katman

    katman Member

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    That's good advice about finding the right place to buy. My local Harman dealer knows nothing about the boiler or furnace products and has little interest in learning. Was willing to order for me only at full retail plus additional costs of approx. $400 for shipping. Delivery to my place would be extra and they would not have it drop shipped. I picked it up from a dealer about 100 miles away. Paid a few hundred more than Vt but the price was good and so is the dealer.
  11. velvetfoot

    velvetfoot Minister of Fire

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    That's a "smoking" price.

    My situation isn't as bad, but he's talking list - a coupon.
    As time passes to Spring, perhaps price will improve.
    I'm thinking just get the unit delivered and take care of the rest.

    As far as shopping purely on price, itt'd be nice to deal locally for warranty issues.
  12. VT_Bubba

    VT_Bubba Member

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    Velvetfoot,

    Go to the Harman Web Page and see the $300 Coupon.

    Note: It does NOT say boiler but my harman dealer took the $100 coupon last year toward our boiler purchases. I would get the Web Coupon (free) and ask your dealer if he will take it on a boiler purchase. If he does, you owe me a Beer !

    Good Luck !

    VT_Bubba
  13. velvetfoot

    velvetfoot Minister of Fire

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    Already did that. $300 off msrp.

    I think I already started the 30 day coupon ticker...oops.

    Price has to better, coupon or not, in spring/summer.
  14. velvetfoot

    velvetfoot Minister of Fire

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    VT_Bubba,

    I've started going through your posts to put it all together.

    Was the following typos? Did you mean > (greater than) instead of < (less than)? I don't want to assume.

    "1) Added 1 Circulator Aquastat on the Pellet Boiler (If Pellet Boiler < 140F and the House control wants heat, then turn-on the pellet

    circulator to provide the hot water to the manifold).
    2) Added 1 Boiler Aquastat on the Pellet Boiler to Hold-Off the Oil Boiler start, if the pellet boiler is hot (If Pellet Boiler < 135F then

    do not allow the house control to get to the Oil Boiler)."
  15. VT_Bubba

    VT_Bubba Member

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    Velvetfoot,

    Yes, my "<" symbols should have been ">" symbols ! I noticed that after I submitted the posts. I hoped Intelligent readers like you, would understand my incompetence. My apology for being lazy on my posts (typing, spelling, English, punctuation, etc...). Hopefully, my technical experience and advice is better than my communication skills....

    Also, pay close attention to the Aquastat partnumbers (Honeywell L4006A vs L4006B) ! One makes contact on temperature rise (Circulator Control) and the other makes contact on Temperature Fall (Boiler Control).

    BTW - I'm guessing your not going to get a better price out of your local dealer on the off season (IE: More than the $300 coupon - I hate to see you lose that $300).

    Good Luck on your price negotiations !

    VT_Bubba
  16. velvetfoot

    velvetfoot Minister of Fire

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    VT_Bubba,

    I thought that's what you meant but I didn't want to assume.

    I will check out those aquatats.

    On price, yeah, plus any warranty good-will would be a plus.

    He's putting some prices together for different scenarios.
  17. Matt_VT

    Matt_VT New Member

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    This is a great thread! This Tarm schematic seems to no longer exist, or is not accessible by mortals. Do you happen to have a copy of it? I'm currently running a PB105 in series w/ my oil boiler. I was pretty unsure about the heat lost through the oil unit, but my plumber convinced me that simple is better. Sometimes that's hard to argue. But we did install some Tees and manual valves so that future possibilities can be explored. I figure I'll see how this season goes; it will give me some time to think about it. I noticed someone commented that heat lost goes into the room anyway, I think a good deal of heat also goes up the chimney of the unfired boiler, think about it...

    Thanks,
    Matt
  18. heaterman

    heaterman Minister of Fire

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    I will say to ANYONE considering a pellet boiler that you really need to check out Windhager before you pull the trigger.

    We have one of the BioWin Exclusive models up and running near our place and it is amazing. Flue temps run less than 230* and after 7 weeks of use the inside of the flue pipe has a film of dust on it but the metal itself is bright and shiny. The guy we installed it for keeps telling me about it and half of what he says I find hard to believe. (4 cups of ashes in 3 weeks of burning!?)
    I have to get back there with my combustion analyzer and get some measurements on that thing. It has to be pushing 90% efficiency.
  19. VT_Bubba

    VT_Bubba Member

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    Hello Matt_VT,

    I recently went to that HS-TARM link above and found they had removed those multi-boiler schematics ! I was really bummed that I never kept a copy. They had basically ever type of multi-boiler installation possible.

    BTW - I agree with your statement about the heat going up the unfired boiler chimney (direct vent boilers are a little better on that issue). I also don't like that the oil boiler must heat the pellet boiler on serries implementations, unless you have some kind of bypass setup for the off season oil operation. But it's hard to argue with simple.

    VT_Bubba
  20. Downeast Farmer

    Downeast Farmer New Member

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    VT_Bubba--
    Why do you need the oil backup to a pellet boiler? Is that like having an oil boiler backup to an oil boiler? I thought one of the advantages to pellet boilers is that you don't need a backup as long as you have a large enough pellet hopper. No?
  21. VT_Bubba

    VT_Bubba Member

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    Downeaster--

    My Solar DHW system, Pellet Boiler, and Oil Boiler with Indirect DHW tank all work together automatically as needed (No manual switch overs required). I have oil back-up for several important reasons :

    1) Sometimes we go away in the winter (Kids and Grandbabies live out of state - You can't stop GrandMa_Bubba) ! We have made it 4days and 3nights in zero-degree weather over xmas last year, with reduced house temp settings, using 1 HF60 hopper load of pellets and an initial load in the woodstove before we left the house. It's good to know the oil boiler will kick on if the house ever needs heat and the pellet boiler is cold for any reason.

    2) Summer DHW use when the solar can't keep up (Kids visiting), or several days of rain\cloudy. Keeping the pellet boiler at temp in the summer months, just for an occasional DHW call, just does not make any sense for me. I use less than 20 gals of oil a year !

    3) I personally believe my HF60 is undersized for my house. With my woodstove running in the basement it's perfect. However, if I ever had to heat my whole house in below zero weather for an extended time, I don't think my little HF60 could handle it. In my system the oil will always kick on if required. I just happened to be in my basement and witnessed a rare oil-boiler assist to my pellet boiler one time last week, when 2 totally cold zones kicked on at the same time and the pellet boiler had to go through an ignition cycle. My oil boiler assisted for about 10mins while the pellet boiler came back-up to temp, then the oil shut-down.





    My oil back-up is rarely used, but I would never go without some kind of high reliability back-up system.



    VT_Bubba
  22. VT_Bubba

    VT_Bubba Member

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    Matt,

    I was just looking around the woodboilers.com web site and found some updated plumbing schematics. You need to click on a product type, then look for the documentation tab for that product. You may find the wood boiler schematics more helpful. I tried to attach the PDF file, but keep getting an error on upload.

    Good Luck
    VT_Bubba
  23. Matt_VT

    Matt_VT New Member

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    Great, thanks. I see it now. There's a lot of info in there. Some are relatively straightforward. Others get fairly complex - I think some of the components in those could set you back quite a bundle. I'm up and running in my simple series configuration (install done in the dead of winter so couldn't mess around), but I have to tinker soon. I think my first priority is to make it so my oil boiler doesn't run. Second priority get it out of the loop. The deal is it's not a cold start boiler, and I've got no reason to buy a new one. Tell me if I'm wrong, but I think the only reason a boiler can't cold start is the manufacturer didn't make it robust enough to handle a bit of flue gas condensation. Now if I make it so the oil boiler never turns on, unless the pellet boiler is truly kaput, then no flue gas, no reason it has to stay warm. Am I right? I don't have the details worked out yet, but I think it's something like this - a normally closed relay that is latched open by a momentary switch (labeled "oil boiler off"). An aquastat near the pellet boiler that closes cold, but connected to a time delay relay. So... the oil boiler is off. But if the pellet boiler ever goes cold for more than 20 minutes, then the oil boiler is switched into its normal operating mode until you correct the pellet boiler issue (add pellets or whatever) and reset the momentary switch. Sound like it could work? Then when I change my plumbing I'll still be able to use (or slightly modify) my oil boiler on/off plan. More to come regarding plumbing...

    Matt
  24. old wethead

    old wethead New Member

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  25. old wethead

    old wethead New Member

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    hi, im new to the forum but I have been putting boilers in for yrs... I am considering a hydroflex 60 and solar dhw to add to my hot water system... where did you get your solar panels and is it a drainback system?... roughly what did it cost? thank you for any help you can give... I live in the north of ny ... near Massena.... we get cold and snow probably similar to vt... thanks

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