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What's your opinion on this design...

Ross_24 Member Posts: 82
Interested in what people think of this design.

Conventional oil-fired boiler, DHW priority.

What would you change? Our goal is to make this as simple a design as possible. It's a rebuild from a past screwy job. All the radiant pex lines and high temp baseboard lines are all hanging in the basement ready to go, it just needs some re-piping.


  • heatpro02920
    heatpro02920 Member Posts: 991
    edited April 2014
    Looks expensive..

    Them taco blocks cost as much as a gas boiler, lol....

    I would pipe it p/s with a alpha pump on the primary, then I would run a bumble bee for each zone. For the low temp radiant I would run a fphx with an aquastat run a bumble bee on each side of it. Use a SR504-exp control with a pc700 to control your primary pump, odr, and priority DHW and zoning....

    The 5 bumble bees, alpha pump, exp control, and pc700 will cost around what the mixing block will cost, lol...

    It will give you delta t operation for each load, delta P for your primary loop, ODR, priority dhw, and low high temp separation for your radiant..

    We all do things different, I prefer not to use mixing valves and zone valves if I can get around it. FPHX have come a long way in reliability and cost, I like how they control radiant with a simple digital a419 aqaustat tired in and a pump on each side.. and you can save costs by teeing your water feed, expansion tank, PRV rig to take care of both sides of the fphx..

    You can make it look really nice with some webstone swag..


    off the top of the hydro-core http://www.supplyhouse.com/Webstone-HCE4-53-1-Union-x-3-4-Sweat-Hydro-Core-End

    off the top of the circhttp://www.supplyhouse.com/Webstone-50403-3-4-Sweat-Isolator-Flange-Pair-7787000-p

    looks expensive but when you factor in the parts and time its only about double the cost of doing it with separate parts and the added labor, but it looks better, works better, saves time, and has a lot less leak points...

    not sure what size hx you would need but they arent as expensive as they used to be http://www.supplyhouse.com/FlatPlate-FG5X12-6-6-plate-3-4-Thread-20-GPM-Heat-Exchanger-5-x-12 I use this same one on a walkway snow melt, its been there for 4 years no issues... I have done plenty of radiant jobs with fphx and they are worry free work machines...
  • Ross_24
    Ross_24 Member Posts: 82
    edited April 2014

    Always like to see what others are thinking. Thanks!

    Also, I may be getting a Taco RMB for much less than others? It's not THAT expensive..
  • Rich_49
    Rich_49 Member Posts: 2,703
    edited April 2014

    an HX at all on the radiant ? It is clearly marked HePex so no HX . Most economical scenario for the low temp portion would be Taco 3/4 I Series mixing valve w/ ODR and the correct circ for that manifold . Done and done .  Way easier than either of the methods described . Give the Indirect it's own pump too you just saved 600.00 .  The circ handling the high temp zones will more than likely be way oversized for the 2 zones of baseboard if you size it for the indirect also and it vry well may sound like a freight train running through the bb , not real pleasant . 
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • CMadatMe
    CMadatMe Member Posts: 3,086
    I Do an I-Valve

    Way before I'd do that RMB and then use the extra $$ I saved to use Bumble Pumps..
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • SWEI
    SWEI Member Posts: 7,356
    Or buy a Viessmann

    and let it manage the mixing valve with the onboard controls.
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Nice One SWEI

    Don't think its in the budget...lol..
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • SWEI
    SWEI Member Posts: 7,356
    Shouldn't cost much more

     than the boiler + RMB + extra labor + extra fittings.
  • heatpro02920
    heatpro02920 Member Posts: 991
    Seems expensive to me

    Last one I bought was over 1000, just seemed like a lot for what you get in the box, the pump block and a few sensors.... For a couple hundred bucks more you can get a 52K BTU GWA-052 gas boiler and run it at 105 degrees just for the radiant, lol.... Don't worry about mixing at that point... Or even a simple rinnai tankless just for the radiant for that much money, at least then you get something for your thousand bucks.....

    Granted they are nice and they work well, just seems like a lot of money for what you get, I love Taco and they are in my back yard, and I have met the owner John, he is a great guy, lol, but that RMB should be like $470 tops :)
  • Tim Potter
    Tim Potter Member Posts: 272
    combo Buffer & DHW

    My last sawzall surgery in my 2nd duplex I Installed a TurboMax 44 combination buffer & DHW. WOW I like it, It has very LONG run times on the boiler & makes gobs of Hot water for the after ski showers. A Honeywell AMX tempering valve limits the DHW temp. TurboMax makes an Indirect with 4 boiler water tappings especially for use as a buffer, but after a call to their tech dept, they told me how to use the tappings on the air bleed & tank drain to plumb in a tekmar 361 injection for the infloor radiant. An esbe Thermic protects the boiler from low return temps.

    Looks like your system would be a natural for this, substitute the iseries 3way or 4way for the tekmar injection & run the baseboard off boiler temps, you could even add an inexpensive boiler reset to vary the boiler temps from say 140* to 180* or some such.

    I used an alpha on my radiant side, but the "B" looks interesting too

    Winter Park, CO & Lenexa, KS
  • heatpro02920
    heatpro02920 Member Posts: 991
    I know I can buy

    a slant fin, williamson, hydro therm, ect gas boiler for a few hundred more than the rmb costs!!!

    A v-man may be a little more than that though, lol...

    I have it in my head to separate all low temp radiant and high temp DHW/base board/Hydro air/ect lately.... I just quoted a job to replace a Burnham v7 oil with a solo 60 and a solo 110, the houses heatloss comes to 128K, the radiant side of the house does around 28K of the total load, so I quoted a solo 110 to connect to his existing indirect, bb, and 2 air coils, then a solo 60 to run the radiant, I also quoted a 175 to run the entire house, believe it or not the dual boiler setup wasn't much more {when you look at the entire job that is}...

    I am so sick of changing mixing valves and water tanks. I got a new customer that called in while I was away with some leaks, it turned out she let her glycol get too old and it destroyed her mixing valves, she has 11 of them and they are all in rough shape, I havent seen it with my own eyes yet, but I am most likely going to fphx that job and repipe what I can...
  • Wethead7
    Wethead7 Member Posts: 170

    I would relocate the main pump to the outlet side of the air separator. That would improve air removal.