Hot water baseboard loop for basement

steamobsessed

Ok to run circulator pump while boiler making steam?

I recently installed a hot water circulator pump to resurrect an old basement baseboard system tied into the return lines that has been inoperative for many years. A plumber friend of mine told me that I should only run the pump when the system is not calling for steam because the 200+ degree temperature water will burn out the pump which is water lubed by the way. This has proven to be very inconvenient because I want to keep the basement warm throughout the day. Can I set the basement thermostat to 72 and just leave it? Or is this bad for the pump? I guess a related question is also whether running the pump while the system is calling for steam is bad for the rest of the house.

KC_Jones

Which pump do you have? What is it's temperature rating? As far as I know the pumps you use in that application have a temp rating plenty high to allow it's use no matter what. Have you read this article?
https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/

steamobsessed

I just took a look at the pump and it is rated for 230 degrees. I'm no scientist so I don't know how hot steam is but imagine that the return water is never more than 212. Thoughts on whether 230 degree rating is sufficient for continuous use?

steamobsessed

Some photos of the install

EBEBRATT-Ed

A water lube circ probably won't last. The sediment in the steam system will chew it up. A better choice is a bronze pump like a Taco 110 with a separate bearing assembly.

Dan writes about this in "How Come"

SWEI

That pump has a cast iron volute.

steamobsessed

And what does that mean

SWEI

The condensate will likely eat it over time. Best bet is a three piece pump with a bronze or stainless volute, but a wet rotor stainless volute would outlast the CI.

vr608

I have stainless steel Taco 007 units for this application; one for my baseboard zone and the other for my indirect DHW. So far no issues, hopefully stays that way.

hboogz

Steamobsessed - what is the gray box to the right of the taco? Could you also explain the placement of the ball valve and blow off valve? I suspect you want to close the ball valve and drain the water as its leaving th boiler to get any air out of the loop?

Learning as I go,

Harry

steamobsessed

The gray box is a Honeywell probe style aquastat (set to 130 degrees) connected to the basement thermostat. When the basement thermostat calls for heat, it turns on the taco and the aquastat keeps the return water at 130 degrees (unless the upstairs is calling for steam). I installed ball valves on either side of the taco to isolate the pump in case it needs replacing. Also when I drain water from the boiler I shut the ball valve closest to the drain to prevent air from entering the loop. There is no blow off valve.

hboogz

Awesome! Is that blue drain valve to the right of the yellow ball valve where you drain the boiler? When you drain you obviously turn that yellow ball valve right?

Is there a right direction that taco is suppose to be installed? Push or pull? Does it matter?

steamobsessed

The taco is directional. Mine is flowing towards the boiler drain and there is a check valve on the other side of the boiler following that direction. It works perfectly and this is what a plumber friend suggested but I honestly don't know if this is the optimal direction. Some of the plumping was already there including the check valve. Maybe someone else can chime in on this. Yes I close the yellow ball valve and use the blue handle to drain the boiler.

steamobsessed

Here's a pic showing direction on pump

steamobsessed

Pic showing direction of pump see arrow

hboogz

Steamobsessed - Thanks for the pics. I would love to hear some folks who have experience with hot water loops as well. I wonder if it matters which side of the boiler the taco gets installed. I suppose it wouldn't matter so long as you have a true loop created. Since you're system is working perfectly, something must have been done right. lol

I have a hot water loop in a home I own where the loop connects to same side of the boiler. In other words the copper terminates into the wet return and the other end of the loop terminates behind the sight glass connection with a TEE. It's a bit strange and have to try and fix it.

Thanks again for the pics, it makes visualizing the right setup so much easier.

vr608

Just to add, if you use a bypass on the return line you should be able to temper the water to reduce your supply temperature. There is a diagram on the System Help Center site that I referenced quite a bit during my install:

https://heatinghelp.com/systems-help-center/category/steam#hot-water-zone-off-a-steam-boiler

hboogz

Thanks vr608. I've been reading and re-reading that same article for the past few days.

vr608

Good deal, I still review it occasionally. I posted a thread sometime back about my loop; despite the ongoing minor issue I'm pretty happy with the configuration, and there are a few pictures that you can reference.