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[nightowl]

Hello everyone,great site info. thanks. my problem is i am getting a 30 degree temp drop across main heat coil 175k. I have e1400 cb oo9 taco at boiler, 400' total 1" pex, side arm exchange,175kcoil,and44/66/ 2speed hanging heater about a 10 degree drop , 4 temp guages,about 8 ellbos,8 ball valves.should i add a second pump at 175k heater in line or the close tee way to come on with blower or just a larger main pump at the boiler. what size pumps? tthanks

[willieG]

Hello everyone,great site info. thanks. my problem is i am getting a 30 degree temp drop across main heat coil 175k. I have e1400 cb oo9 taco at boiler, 400' total 1" pex, side arm exchange,175kcoil,and44/66/ 2speed hanging heater about a 10 degree drop , 4 temp guages,about 8 ellbos,8 ball valves.should i add a second pump at 175k heater in line or the close tee way to come on with blower or just a larger main pump at the boiler. what size pumps? tthanks

at the high head you are near, the 09 would outdo an 011 but even the 09 is not sending enough gpm (in my opinion) an 013 should give you 7 to 9 gpm i think both the 09 and 011 would be working very close to their capacity and no room for any calculating errors..the 013 would be able to pump
i think your head pressure is in the range of 26 to 30 feet...the 09 at 26 will pump about 4 gpm, at 30 about 3 the 011 will do about 7 at 26 feet of head and will stall out and pump 0 at 30 feet of head the 013 will do about 12gp at 20 feet of head and 7 gpm at 30 feet of head

[Scott7m]

Hello everyone,great site info. thanks. my problem is i am getting a 30 degree temp drop across main heat coil 175k. I have e1400 cb oo9 taco at boiler, 400' total 1" pex, side arm exchange,175kcoil,and44/66/ 2speed hanging heater about a 10 degree drop , 4 temp guages,about 8 ellbos,8 ball valves.should i add a second pump at 175k heater in line or the close tee way to come on with blower or just a larger main pump at the boiler. what size pumps? tthanks

at the high head you are near, the 09 would outdo an 011 but even the 09 is not sending enough gpm (in my opinion) an 013 should give you 7 to 9 gpm i think both the 09 and 011 would be working very close to their capacity and no room for any calculating errors..the 013 would be able to pump
i think your head pressure is in the range of 26 to 30 feet...the 09 at 26 will pump about 4 gpm, at 30 about 3 the 011 will do about 7 at 26 feet of head and will stall out and pump 0 at 30 feet of head the 013 will do about 12gp at 20 feet of head and 7 gpm at 30 feet of head

Yea I've spoke with him on the phone a while back and figured he was around 4gpm, he def needs to be moving more water.  I wanted him to add a close t loop to reduce some head and have a small pump come on with unit heater

[nightowl]

I have bypass valves on the hanging heater and when its bypassed i still get the same temp. drop across the main heater. So not understanding how a close tee with a pump will reduce any head at the hanging heater.would a close tee setup and pump that came on with blower move water faster across the main heater and reducing temp loss? It is one  loop system side arm first,175 exchanger second,hanging heater last

[slimjim]

What size piping are you using? as I understand your issue it is all plumbed in series am I right? if so what size is the smallest piping in the system.

[nightowl]

the whole system is 1" pex.

[slimjim]

I may be wrong but what I think is being discussed here is primary secondary, imagine a 1 inch loop around and back to the boiler or heat exchanger, straight through tees instead of 90's then out of those closely spaced tees you put another small pump on each heater, you will get better flow to each unit heater individually than in a series, even at the furthest unit heater because you will have better flow from the primary loop to service the secondary loops

[Scott7m]

Yea..  The water wouldn't have to be flowing through heat exchangers that werent calling for heat

[nightowl]

what size pump shoud i use at the 175btu exchanger with the close tees?and should the pump at the boiler be larger? thanks for all your help.

[slimjim]

Grundfos 15-58 should be fine on the secondary loops and the main loop should be upsized to maybe the alpha or even a 26-96

[Scott7m]

I'm gonna agree with Willie, it needs to be a bigger pump

Slim, isn't the alphas max the same as a 15-58? 

[slimjim]

I believe they are a bit larger volume, iv'e only tried a couple on primary loops as they are a bit pricey, I thought they were about 14 gallons per minute at o head on high

[RSI]

The Grundfos Alpha (15-55) is just slightly smaller than a Grundfos 15-58. You may be able to use one in series with a 15-58 or two in series so not sure how well that would work.

[nightowl]

would the grundfos ups26-99fc 3 speed work as well ? thinking of useing low speed just for dhw in the non heathing months at the  boiler.

[slimjim]

You are correct RSI, the alpha is a bit smaller than the 15-58