Single or 3 sped Cir. Pump?

[Rburke65]

Hi guys! Rookie here. I'm finally got a plumber to pipe up my Argo electric boiler for my 1800 sq. ft. shop. 6 300' loops, single zone. He suggested a 3 speed circulating pump and my question is what determines a single vs a 3 speed pump? Thanks for any info....and I hope I put this in the proper catagory.

 

[Dana]

Ah, hydronic design by hackery- gotta love it!

If you don't know the flow requirements of the system, how are you even going to specify which 3-speed?

Seriously, calculate the pumping head of your system at ~4 gpm, and size the pump accordingly. It'll be enough, and probably not too much. If the system had a fossil-burner boiler and you were concerned about conserving pumping power use it would be worth doing the analysis on it, but since the power used by the pump heats up the place as efficiently as the electric boiler, there's no point to optimizing the pump efficiency- it just has to get 'r done, with out over-pumping to the point that it erodes the boiler or plumbing.

 

[Sponsor]

 

[BadgerBoilerMN]

Make sure your electric boiler has an outdoor reset feature.

 

[Dana]

I don't think Argo boilers have an outdoor reset option (or do they?) It would be nice if they did but...

 

[BadgerBoilerMN]

Most boilers from the 50's do not. We use Electro, Thermolec and the relatively new NexGen. All have outdoor reset, model dependent.