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[mlappin]

Think u need to re read that.  I'm not changing pumps but he is.  Mine is on the stove his is not.  Mine is fine his needs replacing once per year.  Secondly like I said u need water flow coming in being the same or more as going out.  Some of this gets over calculated when it is so very simple. Pretty much what u explained. I run the cheapest pump on the market so I hear going 2 years strong with way more than it should be doing. Having it in the basement IS fine if you can have the correct flow coming in as going out.  Pretty much what u said.  I don't think that is thinking wrong, that's thinking logical in my eyes.

Never said you, meant those that only mount in the basement because they don’t want to change one outside, anybody that’s really done there research usually puts the pump at the stove, so much easier to get the air out for starters, and its not like they are going to go out yearly when mounted at the stove so the argument of having it in the basement is moot. Got almost 15 years out of a grundfos on my old stove, no screen or anything before the pump, now its in the basement on snow melt duty.

Calculating the correct flow coming in would be either gravity flow or by head pressure, therefore you need a pump that won’t move much more than that or you’re cavitating it. Circulation pumps are not self priming, IE won’t pull water or build a vacuum to pull water to them.

[aarmga]

I agree 5gpm is more than enough that I have found. You are right I'm not "lifting" my water 12 feet I am pushing it uphill 12 feet.  I do however push it 6 feet almost straight up from the basement and I push it another 6 feet exactly straight up 90* from the 4ft bury to 2foot loop back into the stove that's where my thinking came from.  I did this long before I knew it would be better doing gradual grade rises but it works very well for how bad the line install was. I was thinking keep the line buried for longer is better when really it shouldn't matter that much for the frost line issue. I am using close foam insulated pex so I'm not going to redo it.  When I get my garage line dug in this summer it will be done the correct way.

[RSI]

I'm sure you have enough head pressure on the push side being so far from the stove that your pump doesn't move a lot of water. My guess you would be in the 4-5 gallons per minute range.  That being said you may have enough feed for the pump that it doesn't have any cavitation issues.  Some have theirs only 75 or like my friend 90 feet from the stove with very little drop in elevation. His pump is pushing 10gpm at that distance (calculated). Since these pumps don't "suck" water at all I believe his pump is starving for water all the time because he isn't pushing water back to the pump.  It is basically gravity feeding to the pump through a 1-1/4 line. I believe it's hard to get 10gpm that way when he pump only pushes 10gpm back to the stove.  I hope u can picture what I'm saying.  Basically as long as u get a supply to the pump that it needs at all times it will be fine.  I'm not one to believe all this head pressure vs distance vs line size crap because none of it actually calculates outs to a real live test.  I push my water 260 feet, 130 both ways, and I lift the water about 12 feet.  My pump technically shouldn't be able to do this or at best push only 1gpm but it does like 6 or 7 because I can over flow a 5 gallon bucket at the stove where the pump is mounted 260 feet later.   That's why I always make sure my pump gets adequate water flow by me physically testing it before the install because those numbers equations are garbage to me lol

When calculating head pressure in the loop, elevation does not make a difference. (except for being able to fill the line initially)
If you do a bucket test like that, you need to have the discharge pipe at the same level as the top of the water in the boiler? If the height is higher or lower, it will change the flow rate.

[aarmga]

Think u need to re read that.  I'm not changing pumps but he is.  Mine is on the stove his is not.  Mine is fine his needs replacing once per year.  Secondly like I said u need water flow coming in being the same or more as going out.  Some of this gets over calculated when it is so very simple. Pretty much what u explained. I run the cheapest pump on the market so I hear going 2 years strong with way more than it should be doing. Having it in the basement IS fine if you can have the correct flow coming in as going out.  Pretty much what u said.  I don't think that is thinking wrong, that's thinking logical in my eyes.

Never said you, meant those that only mount in the basement because they don’t want to change one outside, anybody that’s really done there research usually puts the pump at the stove, so much easier to get the air out for starters, and its not like they are going to go out yearly when mounted at the stove so the argument of having it in the basement is moot. Got almost 15 years out of a grundfos on my old stove, no screen or anything before the pump, now its in the basement on snow melt duty.

Calculating the correct flow coming in would be either gravity flow or by head pressure, therefore you need a pump that won’t move much more than that or you’re cavitating it. Circulation pumps are not self priming, IE won’t pull water or build a vacuum to pull water to them.

I understand and sorry for the misinterpretation.  I work for a large ductile installation company for gas/fiber optic/power although I'm a diesel tech I do understand how flow works with water in this types of pipe. I have learned that you need almost 1.25" the size pipe for a gravity fed pump that is doing 10gpm.  Again this is a  calculated theory and I rather use my hands and eyes to prove this theory.  I have found that it does work fairly well without any restrictions in place like a screen. So with a 1 inch line I should have a 1.25" gravity fed line to feed that said pump if it can push 10gpm in the 1inch pipe. My natures comfort dinosaur smoke dragon does have a 1.5" feed pipe going to the pump so I'm sure that is keeping my cheap broeder pump alive.  It's too bad we couldn't have a small trash pump with a screw impeller that did draw suction at the fill line. I think 2" is the smallest I've found and they are big money.

[willieG]

on another note, taco pumps must be mounted to their specifications (position of motor) to work correctly and avoid problems like cavitation)

[mlappin]

All depends on your setup, I have 120 feet or so of sidewalk thats heated too, between the DHW, a 110,000BTU HX in the furnace and the sidewalk, with only 5gpm my delta T would be horrendous if everything was running at once, if its cold enough out the sidewalk can pull harder than the DHW and the HX in the furnace.

I’m running roughly 117’ of Logstor, then it’s all 1” copper in the basement with primary/secondary loops to everything, running a Taco Delta T pump that keeps up very well if you ignore the lag. Will most likely be adding a whirlpool tub in the future along with some radiant or something upstairs.

The wife has mentioned a time or two about doing a heated driveway for where she parks, only 75’ of that then….

Told her once I figure it out she can cut the extra wood.

I know how hard the sidewalk pulls, my system would fall flat on its face if I was only heating the wheel tracks for that drive.

[RSI]

What is the lag from? Do you have the sensor a long way from the heat exchanger?

[aarmga]

When calculating head pressure in the loop, elevation does not make a difference. (except for being able to fill the line initially)
If you do a bucket test like that, you need to have the discharge pipe at the same level as the top of the water in the boiler? If the height is higher or lower, it will change the flow rate.
[/quote]

Does waist high count??? I know that's 2 feet lower than the top of the water in the stove but that's where I did my bucket test.  What kind of head pressure am I running at 260 feet then? I did calculate elevation change one direction as that's how I was taught to do so.

[mlappin]

Delta T pump is at the stove, depending what kicks on in the house and the fact the sensors are mounted to the black pipe instead of immersion, the delta T can get up to 30-40 degrees before the Taco can compensate, once it does I can run a steady rock solid 20 degree delta T with everything going, this is watching the gauges at the boiler.

[mlappin]

When calculating head pressure in the loop, elevation does not make a difference. (except for being able to fill the line initially)
If you do a bucket test like that, you need to have the discharge pipe at the same level as the top of the water in the boiler? If the height is higher or lower, it will change the flow rate.

Does waist high count??? I know that's 2 feet lower than the top of the water in the stove but that's where I did my bucket test.  What kind of head pressure am I running at 260 feet then? I did calculate elevation change one direction as that's how I was taught to do so.
[/quote]

In one direction yes, one advantage of having the pump at the stove, if it’s  pushing to get to the house, that uphill is canceled out by the downhill on its way back, or vice versa.

[aarmga]

All depends on your setup, I have 120 feet or so of sidewalk thats heated too, between the DHW, a 110,000BTU HX in the furnace and the sidewalk, with only 5gpm my delta T would be horrendous if everything was running at once, if its cold enough out the sidewalk can pull harder than the DHW and the HX in the furnace.

I’m running roughly 117’ of Logstor, then it’s all 1” copper in the basement with primary/secondary loops to everything, running a Taco Delta T pump that keeps up very well if you ignore the lag. Will most likely be adding a whirlpool tub in the future along with some radiant or something upstairs.

The wife has mentioned a time or two about doing a heated driveway for where she parks, only 75’ of that then….

Told her once I figure it out she can cut the extra wood.

I know how hard the sidewalk pulls, my system would fall flat on its face if I was only heating the wheel tracks for that drive.

That g400 must be a beastly stove.  Never got the chance to see one in person yet.  I'm hoping RSI will have one in the spring/summer/fall time.  I might have to take a loan from the savings account

[aarmga]

When calculating head pressure in the loop, elevation does not make a difference. (except for being able to fill the line initially)
If you do a bucket test like that, you need to have the discharge pipe at the same level as the top of the water in the boiler? If the height is higher or lower, it will change the flow rate.

Does waist high count??? I know that's 2 feet lower than the top of the water in the stove but that's where I did my bucket test.  What kind of head pressure am I running at 260 feet then? I did calculate elevation change one direction as that's how I was taught to do so.

In one direction yes, one advantage of having the pump at the stove, if it’s  pushing to get to the house, that uphill is canceled out by the downhill on its way back, or vice versa.
[/quote]

That's what I was taught.  Thanks for clarifying that for me.

[mlappin]

All depends on your setup, I have 120 feet or so of sidewalk thats heated too, between the DHW, a 110,000BTU HX in the furnace and the sidewalk, with only 5gpm my delta T would be horrendous if everything was running at once, if its cold enough out the sidewalk can pull harder than the DHW and the HX in the furnace.

I’m running roughly 117’ of Logstor, then it’s all 1” copper in the basement with primary/secondary loops to everything, running a Taco Delta T pump that keeps up very well if you ignore the lag. Will most likely be adding a whirlpool tub in the future along with some radiant or something upstairs.

The wife has mentioned a time or two about doing a heated driveway for where she parks, only 75’ of that then….

Told her once I figure it out she can cut the extra wood.

I know how hard the sidewalk pulls, my system would fall flat on its face if I was only heating the wheel tracks for that drive.

That g400 must be a beastly stove.  Never got the chance to see one in person yet.  I'm hoping RSI will have one in the spring/summer/fall time.  I might have to take a loan from the savings account

Yah it is, thing is after getting all new windows in the house and tightening the shop up considerably trying to keep mosquitos out after thirteen inches of rain in August, I’m going to downsize to a G200, wanted to do it last weekend when it was sixty here but I don’t have one sitting here and neither does my distributor, instead looks like it will be after winter returns. Once you can feel the return water from the sidewalk start to warm up, it doesn’t pull near as hard, but if its cold enough out at first that glycol may be well below zero.

[RSI]

Whether the pump is in the house or at the stove, the uphill / downhill will always cancel each out. (assuming pump getting proper feed water, etc)

[aarmga]

Do u have a mixing valve somewhere or does that cold antifreeze head right into the stove?