Boiler opinion wanted: Laars Mini-Therm

JohnNY

Hello all,
I'm soliciting opinions on this Laars Mini-Therm boiler. I like the idea of having my guys easily carry 200,000 BTUs down rickety old Brooklyn cellar steps rather than risk injury with a 500-pound piece of cast iron as they have for decades.
https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Laars-JX200NLIU1-Brochure.pdf

JUGHNE

One would think they would have included the shipping weights in the spec sheet.
Certainly less than standard CI.

EBEBRATT-Ed

Flow I think is the key to keeping them happy. Primary Secondary. They get a lot of use in pool heaters etc.

I bet @Alan (California Radiant) Forbes see's a lot of these

jad3675

JUGHNE said:

One would think they would have included the shipping weights in the spec sheet.
Certainly less than standard CI.

supplyhouse.com has the weight listed on the product page - the 100K unit is 145lbs.

John

DanHolohan

What Ed said about proper flow rate. They work best on primary/secondary. Year ago, I did some work for them. I asked their engineers if they ever considered making a steam boiler. He said they had one now. "All you have to do is use the wrong pump," he said.

Pipe it right (as I know you will) and I think you'll like these a lot. And your point about the rickety Brooklyn stairs would sure be my convincer.

hot_rod

I would add that they like a consistent load as they are usually a fixed output. Some models had two stage gas valves.
On a multi zoned system, especially with micro zones a buffer may be desired.
They need boiler return protection if used on low temperature radiant.

Hard to beat copper as a heat exchange material, these have a long proven history and are fairly bulletproof even in abused installations These and other copper tube brands were the go to in the early radiant days.

Alan (California Radiant) Forbes

Agree with all the above. I service about 200 or more of them here in the Bay Area; their JVS Mini-Therms were very popular in the 80's and 90's and are still going strong; almost indestructible. They will soot up when they serve radiant unprotected, so 1°-2° piping is in order.

BigRob

The delta T pump across the low loss header is cool. The literature mentions adjustable water temperature and outdoor reset. I guess the control PWM's the gas valve?

JohnNY

DanHolohan said:

Pipe it right (as I know you will) and I think you'll like these a lot. And your point about the rickety Brooklyn stairs would sure be my convincer.

Thanks, Dan. Every time we lug a cast iron hot water boiler into a house I shake my head and wonder how long we're going to do this for.