www.fueloilnews.com | FUEL OIL NEWS | MAY 2016 45
run off the fan controls as usual, and you would also save them
a ton of money. That would offset the slight difference in price
between the single commercial furnace and the two residential
furnaces. On one job, I had the fan control turn on both blowers at
the same time to increase the CFM. Then I just cycled the burners.
On to steam. Say what? Yeah, steam! Picture this job. It's a com-
mercial, steam-heated building with four zones. Three zones have
motorized valves which open on a call from the three space ther-
mostats. These allow whatever steam is in the main to go to the
radiation without calling in the burner. The main zone has no zone
valve and runs the burner not only up to the limit (let's hope it never
fails or you have a potential bomb), but also overheats the hell out
of this zone. Why? Well, if the heat doesn't get to the coldest zone,
they just turn up the
thermostat. Now you're
sitting there saying, "Why
don't they just use the
end switch in the motor-
ized valve?" Because 2"
motorized steam valves
don't have end switches.
The thermostats are low
voltage (24 volts), and
the primary is of a com-
mercial, line voltage,
infrared flame detecting
variety. Add a switching
relay, you say. No, non-
onononono! Two-stage
the sucker! The first stage makes the motorized valve open. There's
steam in the main already. Bingo! The place heats. No heat in the
main? Temperature continues to drop, second-stage makes, burner
fires, you know the routine now. Comfort, efficiency, happy cus-
tomer, job survival!
So, this article should be titled, to paraphrase Mr. Shakespeare,
"Two-stage or not to stage?" As you can see, that is the question.
The next time you get a chance, try two-stage operation. For the
record, that Riello burner is still available and is now called the
40G5D, Figure 3, but you can only get one by buying the Thermo
Pride Premiere furnace you see it on.
See ya.
l F O N
George Lanthier is the owner of Firedragon Academy, a
Massachusetts Certified School teaching both gas and oil, now
celebrating its 25th year in business. Firedragon Academy has
its hands-on training facility in Sturbridge, Mass., at the Beckett
Training Center. Firedragon is also a publishing firm publishing
George's over 60 books and manuals on gas and oil heating and
HVAC subjects. He is a CETP, NATE, NORA, PMAA and PMEF
Proctor and has been a Massachusetts Certified Instructor since
1975. He can be reached at 608 Moose Hill Road, Leicester, MA
01524. His phone is 508-421-3490 and his website can be found at
FiredragonEnt.com
Figure 2
Figure 3
