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[willieG]

well this is the first time in about 5 years i have seen snow on the lane over my pipes and the ground froze 250 of thawed ground in mid january had to be using a lot of btu's i am calculating by the wood pile so far that a savings of about 4 bush cords or more. that will work out to about 1 free year in every three or if i were to sell the 4 cords per year i save at (the going rate here) 200 bucks a bush cord x 4 that is 800 per year 4 years and my pipes are paid for

plus, if you are running your domestic water on your OWB you pretty much need it to run 24/7  if the water in your underground pipes has to travel 250 feet and it had cooled to say 100 degrees before any demand is called for, your domestic water will be luke warm for a few gallons before it is up to dishwashing temps. (those are my thoughts anyway) also talk to any pump guys, they will tell you what wears out a pump faster than anything else....starts! my taco 0011 is original equipment this is year 11, one start per year. On in October, off in June

[Russ Brumit]

I run dhw in both house and shop. Two seperate pumps and water coils in boiler.  Both run on demand.Works very well. Almost endless hot water. I couldn't ask for any better set up other than maybe a ranco instead of the disc style. No need to run 24/7.

 I had heard it was easier on the pump to run on demand than 24/7 . It never made sense to me . I would think what you said would be true.

 

[willieG]

it works for you so i agree...why change what is working.  I have never thought of doing on demand and likely, niether of us are gonna change, LOL

another thing i would wonder (thought it is clear it has never happened to you and you have a long run of pipe)

with the water stopped moving for an extended period of time i wonder if the air bubbles  in the water (we all know there is some in these open systems) could ever migrate to each other in a high spot in the undergorund pipe and cause an air lock

[Russ Brumit]

Not sure .I"ve only been set up this way for a week now . Wasn't sure if it would work so Thats why i went with a switch to go back to 24/7 at the shop. House is perfect  with on demand and has been that way since install last year.  What i was afraid of with the shop was water sitting so long that it would cool and when starting up would overwhelm the boiler . So far so good .
No air locks yet but who knows with time.

  I was wondering , Do you know how many ft of 1" pex it will take to make 1 gallon of water ?

[willieG]

  I was wondering , Do you know how many ft of 1" pex it will take to make 1 gallon of water ?

1 inch pex 0.03128
1 inch pex ala pex 0.04351
so for 1 inch pex it would take about 3.2 feet of pipe to require 1 gallon of water (that is at about 56 degrees)

[Russ Brumit]

Thanks Willie. How much will it change @ 150* ?

[willieG]

Thanks Willie. How much will it change @ 150* ?

how much will temp change? i have no idea i do know that when i start my furnace in the fall the water in the stove i let get to temp before i turn on the pump. it seems to take about 1.5 or 2 min before i feel warmth at the entry into the house and then about one more minute before it feels like it is up to "can't hold on to the pipe anymore" temps