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[oaky]

I recently installed a couple of water temperature monitors, one behind the owb & one in the house for where the lines enter thru basement wall. Currently, the delta-t is 40-45F. At the lowest water temp on the return is 135, usually the first 1-2 hours in the morning, otherwise, about 145 degrees on the return. Owb set at 180/190. Heating a total of 2200 sq ft including basement.
The Taco is running quietly except when boiler temp goes over 195 degrees. Any reason why the huge delta spread with such a light load & ft head?

I have a Taco 007 F5 circulator behind owb connected to the top supply port
60' 1" Pex-A-Pex
40' 3/4" PAP inside basement
One 20"x20" w/a exchanger in gas furnace plenum
Another 20"x20" w/a standalone exchanger 20' from the gas furnace near floor level, this one is seldom used for near my shower.
Total of 10 ball valves with one 1" inline sediment strainer
Circulator is higher than the basement by a few feet

[coolidge]

All your piping insulated?

[oaky]

Yep, about 1 degree temp loss outside lines. No insul on inside lines. When no load, the delta is 10 degrees, I forgot to mention this earlier.

[coolidge]

I had to insulate anything in the basement to help maintain 80, if left uninsulated would be 100 down there.

[Sluggo]

I have the same problem at the same time time of day.  I was told by a trustworthy source that my plate heat exchanger could be on the small side.  He told me not to worry about it.

[oaky]

Could someone figure out the head loss or foot, I didn't take algebra in HS. Once I get this number, I can take it from there, for pump size:

I have a Taco 007 F5 circulator behind owb connected to the top supply port
120' 1" Pex-A-Pex (supply & return)
80' 3/4" PAP inside basement (supply & return)
One 20"x20" w/a exchanger in gas furnace plenum
Another 20"x20" w/a standalone exchanger 20' from the gas furnace near floor level, this one is seldom used for near my shower.
5-1" ball valves
2-1" unions
1" inline sediment strainer w/ball valves
4-3/4" ball valves
2-3/4" Gate valves
2-Brass 1"x45 degree elbows
Circulator is higher than the basement by a few feet

I sent this information to the Taco company, they said they couldn't help me.

[Big Wood]

Maybe try moving the down to the lower port and put the return to the top i run a heat source 1 and it takes the water of the bottom and my old aqua therm i all so pulled of the bottom just a thought

[yotehunter66]

I noticed that too but was a little hesitant to chime in since I'm not familiar with that model. My pump comes off the lower port also. Did you say you only have a one degree drop from the boiler to the inside of the house? So you have a high thermal load or low pump circulation. There are more talented people on here than me that can tell you btus delivered by volume pumped and all that good stuff. Hopefully the will chime in.

[mlappin]

Not sure if I count as one of the more talented or not, but after looking up a Taco 007, the best it can do with 0 feet of head is 20 gpm, but 0 feet of head is nearly impossible unless your loop is extremely short and using a larger line size. At 5 foot of head its roughly 16 gpm, at 8 feet of head it's 10gpm, at 10 feet of head your down to 3 gallon a minute. I'm not sure of the formula to figure head with out knowing what your original target was for flow and Btu/hr. I'm guessing the three quarter line and fittings/valves are raising the head pressure enough the flow isn't adequate and your heat loss is simply radiating out of the 3/4 PAP into your basement.

[oaky]

I've decided to go for the, Taco (0015-MSF2-1IFC) 3-Speed, Max Flow (GPM): 18, Max Head (Ft): 21. This will cover a large range to get 100,000 BTU, I wanted to get a Taco variable speed pump, just not certain of my head loss in my setup.

[oaky]

Thanks to the members who chimed in for their thoughts about my posting. I guess I was hoping for a little more with all the great members here. My pump choice mentioned in my previous posting may be my resolution.

[BoilerHouse]

Here is a helpful guide to select the best pump.  Ironically, it is from Taco, so I don't know why they didn't offer any advice.  At 10 gpm, the 1 inch line has close to a 10 foot head.  The 3/4 inch line will be similar or larger.  The 0015 might be borderline even on maximum, but work through it and see what you come up with.

http://www.taco-hvac.com/uploads/FileLibrary/SelectingCirculators.pdf

[oaky]

I went from green to red, Grundfos 26-99, will get it this Friday.

[mlappin]

I went from green to red, Grundfos 26-99, will get it this Friday.

You'll like it, mines going on fifteen years old and still runs quiet and smooth.

[oaky]

Awesome, thanks mlappin.