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[Bull]

I just installed a Hardy outdoor wood furnace and need to replace the pump. It has a Taco 009 that is bad and I need to replace it but I need one that will pump the farthest (about a 450 foot loop  through 3/4 inch pipe) Any ideas on what to get and where to get it would be greatly appreciated.
Thanks
Bull

[pbrooks]

Talk to the counter guy at your local plumbing supply house.  Not a Home Depot or Lowes, but a real supply house.  They have access to all of the charts, engineering info, etc. to correctly size your pump.  A 009 is probably not big enough.  Look into Grundfos circulators, I hae one and it works well.

[willieG]

i agree, talk to not only a pump guy but some one whom can tell you about flow and head loss and stuff like that. (i am not that guy) your run of 450 feet will actually be more as you add elbows and tees (they all count) your pipe (in my opinion) is undersized. I think 3/4 is good for about 6 to 8 gpm. So yo need to get a pump guy to figure that all out for you if yo pump to hard yo may cause cavitation and couse the pump to overheat or get an air lock in it and burn it out (as most of the pumps we use are lubed by the water)

you may get by with one large pump or you may require 2 smaller pumps (one at he owb and one at the house)

I think you may need the 2 smaller pumps as you only have 3/4 inch lines and to push the gpm you need to sevice your house will require a large pump to account for the friction in that many feet of pipe.

YOUR LINE IS UNDERSIZED do not let anyone here that is not in the business of designing these systems for a living talk you into something that you will be sorry for later. Search out a professional
But do come back and tell us all what did work for you

[yoderheating]

I agree with WillieG, 3/4 is not a good choice for running 450ft. I would think you will have some issues unless you go with a several pumps with high gpm.

[Bull]

Thanks for the replys, I ask the question at .ctwoodfurnace.com/ and was told that the taco 013 would work but the Taco 2400-20-WB Wood Boiler Series, High Capacity Circulators was what he recommended. This is what I ordered so when it comes in I will let you know how it works.
Thanks
Bull

[willieG]

this will be interesting to see  how it works

the pump you have been recomended can produce 8 gpm at 30 foot head

my figuring puts you at almost twice that head loss (but i am not good at figuring this stuff out so you could be way less)
did the person recomending the pump give ou an indication of the head loss ou would be pumping against?

[yoderheating]

 3/4 pipe really requires a lot larger pump then 1" does. I moved and re-plumbed my furnace furnace two years ago. I went from 75ft of 3/4 to 180ft of 1". I was able to reduce my pump size in almost half and still have almost twice the heat. I knew changing the size of line would make a difference but was still amazed at how much it effected my system. Good luck on the pump, I would still bet you will need two 013's to get very good heat off your system.

[juddspaintballs]

Another issue with smaller pipe is the maximum velocity you can flow the water at.  Eventually the friction between the walls of the pipe and the fluid inside will cause enough turbulence that you're barely moving any fluid through the pipe.  If you go with a larger pipe, you can flow the water faster and have higher return temperatures to your wood boiler. 

After this heating system, I highly recommend replacing your PEX.  It won't be cheap to go 450', but it'll save you from ruining pumps every couple of years and it'll give you much better heat transfer into the house. 

Here's the calculation tables from Taco for selecting their circulators:
http://www.taco-hvac.com/uploads/FileLibrary/SelectingCirculators.pdf

It also explains water velocity and the various sizes of piping and how it affects the system.  Very useful to read.

From what I've read so far, just the PEX alone will give you 42' of head.  With fittings and such, you're looking at 60+ feet of head.  The Taco 013 isn't meant for that.  The upside is you can only flow 4.5 gpm through the 3/4" PEX, so at least you can use a higher head with whatever pump you end up using.  Assuming the heat load for your house is only 100,000 BTU per hour, that means you'll have a 45 degree temperature difference between the water leaving the OWB and the water returning the OWB.     That's not good!  180 degrees - 45 degrees equals 135 degrees of water returning to your OWB.  At that temperature, Oxygen in the water and causes corrosion and microbiological organisms grow causing all sorts of problems. 

Good luck with heating this year without issues.  You really need to upgrade your PEX next year.  I'd recommend 1-1/4" for a 450' loop.

[Bull]

Thanks for the advice all, I wish I had checked here before installing the pipe. I had not thought about pipe size as other systems that I know of used 3/4 inch I thought that was what I needed.

[Bull]

Just a follow up on my pump and 3/4 inch line, the pump came in and I installed it today. I turned on the pump and built a fire and it works great. The thermostat on the stove must be bad so I will need a new one but it is heating my house and garage great so far.

[heaterman]

There is no circulator that will move water through 450' of 3/4" tube and survive very long. Keep a spare or two on hand. Just go with a Wilo S21 or a Grundfos 15-58. They'll both do about 2.5gpm under those conditions which is about all you are going to get out of 3/4" pex to begin with. Just for kicks, I ran your scenario on my computer and found that you would need about 3/4-1 Horsepower to get 5GPM out of your tube.

There is no more common problem out there than undersized tube.

[lawrencep]

I had the same thing i had 3/4 and replaced it with 1" i run it 300 ft one way so 600 ft loop i run a bell and gossett series 100 it may be over kill but really moves the water like they said talk to someone at a supply house.