hot water loop to 3rd flr off steam boiler

gabetheplumber

I ran a hot water loop off a steam boiler with proper shutoff valves, perge boiler drains, flow controls, thermometer,aquastat,relay, and a bypass with valve to control water temp. I'm using a taco 010 circulator pump. The loop is for the 3rd flr. The water is not coming back hot and I'm sure I perged all the air out of the loop. Do I need a bigger pump?

Ron Jr._3

The loop might be too high

If memory serves , you max out at 30 feet vertical from where the loop connects to the boiler up to the 3 floor heat . I'm assuming the boiler is in the basement ?



We've been biting the bullet and using an external or internal heat exchanger for any hot water loop above a steam boiler . Alot less headaches .

Danny Scully

Oil Fired?

Is it an oil fired boiler?

HDE_2

Nope

A Taco 010 circulator doesnt have a chance when applied as a open system. It maxs out @ 10' head

Why does oil matter?.

Brad White

I agree with Ron Jr.

Installing a brazed plate heat exchanger will separate the water streams and give you a closed system which can use a much smaller circulator. Just be sure you install a good strainer and blow-down valve on the boiler/condensate side.  The radiation side would be like any closed system with an expansion tank and 30# relief valve. 



In theory, you should be able to force water up 33 feet in an open system, but reality is, the vacuum does not always hold and you lose your charge. Not a lot of room for error. One story, maybe two would be my limit, but then, I would use a BPX and not worry about loss of charge.



 The notion of using a pump with 33 feet of head to get the water up there if it normally drains down, seems silly when you consider a circulator with five feet of head would do nicely.