Understanding primary-secondary pumping

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Understanding primary-secondary pumping

Primary-secondary pumping was invented by Gil Carlson in the early '50s. Holohan's book takes what he learned from Carlson and teaches you to reduce the size of your pipes, valves, fittings and pumps, and how to lower heating system temperature, and all without sacrificing performance or getting into trouble.

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whatsthebigidea

Nicely written and easy to understand. Can you please direct me to a diagram with specs for a two zone (two separate apartments) hot water boiler. The existing boiler is a Utica high efficient 80000 BTU. Boiler Heating Primary Loop / Boiler Secondary Loops with mixing valves is a consideration. Please advise. Thanks.

DanHolohan

Thanks. The diagrams and specs are all in the book that I wrote. You can get it by clicking the link at the end of the article.

whatsthebigidea

Dan, so your book has a two zone (2 apt) diagram?

DanHolohan

Yes.

lornfile

For nine years, a powerful Rayburn, running on smokeless anthracite, has driven two radiators in my house, with no pump. The returning water was almost as hot as the near-boiling water coming from the boiler. I was told not to lag, and told a service engineer that I rarely had water boiling in the radiators because I ran it on tickover. It has taken me years to find out that hot-to-boiling water circulates itself. I understand that a secondary circuit might have to have a pump. So does the primary circuit include the expansion radiator essential for dissipating heat and pressure from the boiler? And what is the English legal position, please (Building Regulations)?

Zman

lornfile said:

For nine years, a powerful Rayburn, running on smokeless anthracite, has driven two radiators in my house, with no pump. The returning water was almost as hot as the near-boiling water coming from the boiler. I was told not to lag, and told a service engineer that I rarely had water boiling in the radiators because I ran it on tickover. It has taken me years to find out that hot-to-boiling water circulates itself. I understand that a secondary circuit might have to have a pump. So does the primary circuit include the expansion radiator essential for dissipating heat and pressure from the boiler? And what is the English legal position, please (Building Regulations)?

@lornfile The exact thing happened to me. I just adjusted the pfsizer valve to 123 and shimmed the gonculator and it ran perfectly....

InventorDude

A guy could go broke buying all your books, Dan, so is there one all-inclusive book you've written that covers it all?

Mad Dog_2

Go broke? Dan's books were always very fairly priced. If one is going to apply his lessons in the field (unless you're just reading for pleasure), one will make a quick return on investment. Last, it wouldn't be very practical lugging around
A huge phone book sized behemoth, would it? Mad Dog

Gordy

Zman said:

lornfile said:

For nine years, a powerful Rayburn, running on smokeless anthracite, has driven two radiators in my house, with no pump. The returning water was almost as hot as the near-boiling water coming from the boiler. I was told not to lag, and told a service engineer that I rarely had water boiling in the radiators because I ran it on tickover. It has taken me years to find out that hot-to-boiling water circulates itself. I understand that a secondary circuit might have to have a pump. So does the primary circuit include the expansion radiator essential for dissipating heat and pressure from the boiler? And what is the English legal position, please (Building Regulations)?

@lornfile The exact thing happened to me. I just adjusted the pfsizer valve to 123 and shimmed the gonculator and it ran perfectly....

I thought it was the phase shift modulator??

ratio

Well, I had trouble with the disconfrabulator, but I replaced it with an old flux capacitor that I had laying around, and now it works as good as it did in 1955!

DanHolohan

@InventorDude my books don’t cost;they save.

RayWohlfarth

The books are your best friends on a late night service call inside an old boiler room when you have people asking every 15 minutes, How long will this take?

Paul48

I think you're missing a marketing opportunity Dan. You could offer the whole collection, along with a free hand truck.

DanHolohan

Good one, Paul! I’ll mention it to Erin. They’re her books now. ;-)

Henry

You used to have a phone app that I used. Is it still available for android? Specially the steam one!

DanHolohan

No longer, Henry. There wasn't enough interest to keep it live. Thanks for asking, though.

lchmb

hmm..think I need to order a book or two...

Sootmaster

I have my home piped primary/secondary and I have noticed an increase in system velocity when the boiler circulator kicks in. Tee's are closely spaced and done "by the book"

It's as if the system circ and boiler circulator are now running "in series"

Any brainiacs out there with a lab that could verify that?

Any thoughts?

What happened to retirement Dan?

Fredm

Hey Guys.

Long time no questions but here is one.

We are having a supply crisis and I wonder if a primary secondary piping strategy can replace the function of a low loss header?

Fredm

sorry guys, this was answered in 2021.

For the rest of the story- I will use a G 3 spd primary pump and an alpha to deal with the varying flows presented by 5 zone valves.

If I am making a mistake- please speak up.