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[jerkash]

I just bought a Legend 4135 and have been working on installing it the last couple of days.  Lines burried, everything hooked up at furnace end.  Waiting on modification for trunk line to install heat exchanger and hot water heater.  I have a couple of questions.
 
I have a three speed pump.  How do I know which speed to run it?  I am 125 feet away from the heat exchanger.

The legend has a heat coil inside the furnace for the hot water and does not use a pump.  Its just two of us and we don't use much hot water and was wondering if it will do the job it is suppose to do.

I have a small shop about 20 feet away from the furnace.  Can I tee into the lines that goes to the heat exchanger at the house and use the same pump for both places?

Thanks

[rhugg]

For Hot Water it will burn you (consider a tempering valve also called a mixing valve) and supply hot water all day as long as you keep the fire burning.  The downside is the delay and getting hotwater.  The way most of these guys run is they heat the water in an existing electric HW heater.  With the legend setup you have all the cold water in the line to dispose of before getting HW.

As for the shop, I don't understand what you intend to use in it, just a radiator?  There are all kinds of ways to skin that cat.  But I don't see using a T.  You could go from the cold side of your water to air HE at the furnace to the small shop.  There is considerable redidual heat and then go back to the Legend.  If it is only a small shop it may be excessive to add another circulator.  Maybe a thermostat controlled valve to send the hot water to the shop.  Not something I have experience with.

[willieG]

if you are only 20 feet away from your shop i would vote to heat your domestic water in the house with a plate exchanger on the main line and use your heating coil in the OWB (filled with antifreeze and water mix) to heat your shop. this would require another small pump but your shop would be on its own loop and also be able to keep from freezing should something go wrong when you are not out there! you sould run this loop as a closed loop if you used an expansion tank.

[Scott7m]

For 2 buildings u need 2 loops and 2 pumps.  I would personally ignore the water coil in the furnace, and install a 20 plate at the hot water heater.  No delays, no 4 line underground pipe, much simpler.

[yoderheating]

 WillieG has a good idea especially if you are planning on only heating the shop when you are in it.

[koutsman]

When I bought my Legend I was already set up with my plumbing because I had outdoor corn boiler(junk) before so I had them take the water coil out and credit me for it !  You could do that then set up how ever you want!!

[jerkash]

Rhugg - Could you explain a mixing valve?
Where and how it tooks up and how it works.

Thanks

[rhugg]

A tempering/mixing valve takes scalding water and mixes it with cold water to get the desire hot water temperature.  So there are two inlets and one outlet.  It is adjustable.  There are two problems with the way Legend makes hot water.  One it is two hot and two there is a longer delay on getting HW than normal because of the added length of line going to to boiler.  Many people do not install tempering valves but if you have kids or visitors you have a safety issue.

Willie has a good idea of using your Legend HW coil as a pressurized loop for your work area.  Then you only have to put antifreeze in that loop and get your domestic HW the way other manufacturers do it (Plate HE and existing HW Heater).  Even so you should control your max HW temp with a mixing valve or valve that stops heating hot water once it is 120F.  Just my opinion.  There are plenty of more experience people here than me :-)

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[jerkash]

Thanks for the info
If I install a plate exchanger (20 plate from what I have read - just the wife and I)
1 - I would tie in the hot line from the Outdoor furnace to the plate exchanger
2 - Exit the plate exchanger and tie into my heat exchanger in my existing trunk line
3 - Exit the heat exchanger in my existing trunk line and go back to the return on the Outdoor furnace.
Is this correct?
Will it make any difference it it goes in the plate exchanger or heat exchanger first?

[rhugg]

I don't heat domestic water that way. Many manufacturers show the 'side arm HE'  see http://www.centralboiler.com/Tech/C100.pdf or http://www.centralboiler.com/Tech/C110.pdf

The plate HE method works the same.  There may be a 'best practice' of where to mount the plate HE.

[Firechaser]

You have it right. Most recommend plate exchanger first because you want your water hot enough

[willieG]

jerkash for what it is worth i use a header system. feed and return. my hot water from teh OWB comes into the house  to a 1 inch header with outlets on it for the furnace, the domestic water eschanger, floor heat, rads in teh basement and a rad in my fireplace as well (no more fire in the house) these "outlets" all have a ball valve on them and they all from the feed header to the "appliance" then back to a return header that are also vlaved. this way all "appliances" are recieving the same temp water and each "appliance" if there is a problem can be isolated and taken off stream for repairs without  haveing to shut down the entire system.

if you are going to run from one 'appliance' to another may i suggest you put a by pass line at each one so you can take one off line if needed.

here is another belief of mine (and maybe not any one else) but if you put 180 degree water through your domestic exchanger the OWB water leaving that exchanger (when you are using domestic water) may have a temp as low as 160 and if that water goes to another appliance it may leave that appliance at only 140 and so on...you can see if you are using multiple  "appliance" you could eventually be getting too cold of water to do any good.

another andvantage i see in the header system is you can add 'appliances" easily as you require them.

perhaps if you add too many you will require a booster pump but so far i have 5 lines running from my header and 1 pump does everything except i have a small pump on my infloor loop to circulate teh water in the floor

good luck with your project

[Firechaser]

No you have to have an exchanger so the domestic water and boiler water don't mix

[jerkash]

Yep Firechaser - I thought about that as soon as I hit the "post" button so then I deleted it!  But it did sound good at the moment.  haha