Got into this late, so various points addressed in various places below.

"L. M. Rappaport" wrote in message
...
On Wed, 15 Oct 2003 20:55:44 GMT, "houseslave"
wrote (with possible editing):



One of the "experts" that visited our home trying to cure a
hard-starting Riello said that he preferred a single line because it
gave the oil a better chance to warm up before going to the burner.


Depends, and I mean, depends.
IF you have 20 feet of indoor line, and 10 feet of outdoor, maybe..and I
mean..MAYBE.

He claimed that the oil had to be over 50 degrees for some reason or
another so he switched us from a double to a single line system, but
since he was never able to cure the hard start, I have no idea if he
was correct.

Funny how all the oil burners here work just fine when you have a couple of
weeks in the teens...


How would a single line system heat the oil any better than a two line
system? This doesn't make sense to me...

Its all about the time in the line, in a heated space...otherwise, total
bunk.


Again, I'm no expert, but it appears he's right. A two line system
uses a blow-by (for want of a better term). This means the oil is
circulating at a constant rate which is considerably more than what is
used. Consequently, the oil spends less time in the heated home
before returning to the tank. A single line system holds the oil in
the feedline until it's used; therefore, it has more time to warm up
in the heated home.

A two line system is self priming. its a much prefered method for old timers
and those that know how to set up a burner system..costs a bit more , as the
pump has to be modified a bit, but thats included in the factory
setups...you have to change a couple of things that are not ready from the
start, but its ok, and you have to use more line.
Its much better for the homeowner, as if the unit should ever drain the
tank, all you have to do is hit the reset. I have been known to even go so
far as to mount the control in a box, near the breakers for added convience
if the unit should trip. The homeowner is told to hit it ONE time, and if it
trips again, call.


Also, I have two oil burners feeding off the same line. We had a problem
with one line starving the other. I had check valves put in and that
solved
the problem. I also read that you can put in a switch that will only
allow
one burner to fire at a time. On my hot water heater I now have a two
line
system and on the boiler's burner I have a one line system. I'll let you
guys know if I have any problems with both appliances this winter. It's
still to mild to tell if my installation is golden. My old Beckett head
had
a .80 nozzle, was low rpm and ran dirty. The new Riello has a 1gph
nozzle
and really heats the boiler to temp faster. The tech also performed a
smoke
test and there was no smoke residue on the paper. I was told that the
Reillo will run super clean compared to my 25 year old Beckett head. I
hope
to see a 20-30% savings. The tech said that my old Utica boiler was
built
like a tank and is made better then the newer Utica.

Actually, if you have two lines that feed off one, all you need is a larger
feeder. Oil and gas, water, etc...principles the same. You cant run two
large units, with larger nozzles, sucking fuel like no tomorrow, off one
3/8ths line. Its all about volume.



The only possible problem you might have with one line feeding two
burners at once (AND I EMPHASIZE THAT I AM NOT A BURNER TECH, so
hopefully one will address this) is that both are sucking oil at the
same time. It's conceivable that one might not have enough suction to
get oil. JUST A GUESS!

The pump is the suction part. As long as both pumps are running, and primed,
you have suction.
Its the volume that each is demanding, VS the volume that is there in the
main feed line that will create issues.
Pressure is built AT the pump..the only pressure on the feed lines is the
weight of the fuel in the tank on it.


At my location, another reason for switching to the one line system
was that our diesel generator was tied into the same line. The last
tech cited the above as yet another reason for switching to single
lines. He put the generator on one line and the burner on the other.
The generator was setup for two lines, but fortunately nothing comes
out of the return line, so we stuck it in a 5 gallon pail and check it
occasionally.

Then its not set up at the pump for two lines, and I suggest that you either
remove the second line and cap the pump with the plug that should be there,
or get it set up for a dual line and get it ran out to the tank.
IF that pump fails, you are going to be vEEEEERy surprised at how fast a 5
gallon pail fills on that small line.


--

Larry
Email to rapp at lmr dot com