Confirm that ECM circulators are OK to run very high hours/day [or continuously]?

sokoloff

In doing some experiments to lower supply water temperatures, I want to check that it's OK to run ECM circulators with very high duty cycles (12+ or even 24 hours per day).

I've found posts indicating that PSC circulators can be run continuously (if you can afford it ), but couldn't find a clear reference to "bless" running ECM circulators nearly or exactly continuously.

I doubt it does, but in case it matters, it's one Taco 007e and one Grundfos Alpha 2 (set on "pressure 2" mode), with the Taco feeding a series run of 3/4" copper conventional baseboard in the converted attic and the Grundfos feeding two housing levels of paralleled cast iron radiators in a converted gravity feed system (so very large black iron piping in the basement).

Comfort is fine (or even very good) currently. I'm experimenting to see how far down I can push the outdoor reset settings to squeeze a bit more efficiency now, but also to evaluate a possible future air-to-water heat pump source.

My primary question here is circulator reliability in 24x7 usage, but other relevant issues are welcome to be covered. Thanks!

hot_rod

At some point when the zones are satisfied, since you are running delta P, it should go to idle mode? Around 7W on the display, barely turning so it can quickly sense a flow requirement.

Certainly better than a stuck rotor.

When the originally arrived in the US they had power cords to plug into the wall. Just supply them with a constant power.
I think some of the new versions also have an exercise function to rev them up occasionally during summer season, so they need to be powered.

sokoloff

There are no zone nor thermostatic valves.

Just a Taco relay control box turning the secondary circulators on (while also calling for heat on the boiler which runs the primary loop). All the rads on the main two-floor zone are paralleled all the time.

(But I think you're implicitly saying that it's OK to leave it in 43W, HI flow, on delta-P setting #2 24x7 if that's what the thermostats called for due to supply water temperature meaning heat influx was exactly matching heat loss at the thermostat setpoint?)

EBEBRATT-Ed

all circulators are designed for continuous use.

hot_rod

As a zone pump, I don't think you want a delta P mode?
Find the lowest fixed speed setting that gets the job done. It depends on which model you have. I think the newest Alpha 15-58 has a head setting, or a gpm setting in different menus. Plenty of options to play around with for best operating condition.

Maybe it runs at 27, or 32W instead of 43? Keep cranking down the speed until it cannot cover the load, then go up one notch.

If it is relay powered it would go off in summer months anyways.

hot_rod

See if this helps clear up the ECM circulator options.

file:///Users/bobrohr/Downloads/Grundfosliterature-6859663-ALPHA-15-58-IO%20(3).pdf

sokoloff

hot_rod said:

See if this helps clear up the ECM circulator options.

file:///Users/bobrohr/Downloads/Grundfosliterature-6859663-ALPHA-15-58-IO%20(3).pdf

That link didn't work (it seems like it's a file on your own computer), but using that info, I found the Installation/Operating instructions on Grundfos' site.

From the description inside that doc, it seems like I do want to use one of the constant speed modes. Thanks for the pointer to it and I've switched the pump over constant-speed #2 for now.