indirect wiring and oil usage

Leo

The new one isn't a beast but that old one sure was. You don't want more than 120 deg at your faucett. As far as not seeing the savings, somethimes that may happen but the comfort difference is worth it.

Leo

Tim Gardner

increasing oil usage to save the boiler?

My oil company hooked up my new Burnham V84 steam boiler to the oil tank and fired it up for the first time this morning. They then CHANGED THE WIRING to the new 53 gallon Burnham Alliance indirect.

So far everything's working great! I'm thrilled!

But I can't keep myself from being curious about the oil company's rewiring. The indirect was and is wired to the T-T terminals of a Honeywell R845A relay (DPST). They didn't change that. But the pump was wired to 2 and 4 while 5 and 6 went to the terminals of the house thermostat on the boiler with one leg through a Honeywell L4006A, as suggested by Glen Stanton in this thread:

http://forums.invision.net/Index.cfm?CFApp=2&Message_ID=10880

In Dan's book, in the topic "Condensate Hot-Water Heating, in response to the question: "How should I control the zone? ", Dan recommends this method as well, if I understand correctly, although not expressly for an indirect:

http://www.heatinghelp.com/heating_howcome6.cfm

But the oil company changed the wiring dramatically. The jumped 1 to 3 in the relay so that the indirect's aquastat now just runs the pump. Then they removed the 5 and 6 wires from the relay and instead wired them to the house thermostat/boiler terminals directly. Then they lowered the L4006A from 185 to 160. Essentially, this boiler aquastat is now a year round thermostat keeping the boiler water hot all year round.

The oil company's wiring is simpler, but is it better? Their justification was that this arrangement will produce hot water faster because the boiler doesn't have to start from room temperature. They also said that keeping the boiler hot during the summer is healthier for the boiler. They can always tell, they told me, when a customer turns their boiler off for the summer and then switches it back on the week before they service it in their yearly maintenance.

Their argument makes sense to me, and I trust the oil company, so I doubt I'll change it. But I'm curious whether this is the best way to wire an indirect, especially in light of what seems like contradictory advice.

Big Ed

Dammed if you do

If a boiler has a chamber or a coil plate its not a good Idea to shut off for the fact of detearation.

The other side ....A hot sitting boiler looses energy. The higher the boiler temperture , the faster the loss..

A compromise.... Install a second L4006A. Wire it to burner control and set it down to 120* to matain min water tempature.. .. The first L4006A set it to 180* and wire it back through the hot water relay for hot water producton..

Tim Gardner

Great idea! Thanks!

Tim Gardner

double aquastat

Is there a double aquastat that breaks two different lines on two different temperatures so I can use the single tapping to function both as a low limit and high limit for the boiler?

If not, is there another kind of double aquastat which could be used along with another kind of relay than the R845A to both keep the boiler above a low temp and cut if off before steaming when the indirect is calling but the house isn't?

Tim Gardner

Honeywell L6081A

The problem with adding another L4006A is that it uses an extra tapping AND it could actually cool the indirect when the boiler is between 120 and 140.

Here's what makes the most sense to me now:

Boiler Temp	nothing calling	indirect only calling	house only calling	both calling
180-220		circ	boiler	circ and boiler
140-180		circ and boiler	boiler	circ and boiler
120-140		boiler	boiler	boiler
below 120	boiler	boiler	boiler	boiler

I'm considering switching the L4006A to a L6081A.

The L6081A has one SPST which breaks on high and one SPDT snap switch which makes one line and breaks another on low. This seems perfect for what I want. I would still wire the indirect aquastat to the R845A T-T. I would run the 5-6 of the R845A to the boiler/house T-T with one leg through the high limit of the L6081A so that the indirect would turn on the boiler but not make steam. As before, I'd run the circulator off #4 of the R845A, but this time I'd run it through the L6081A make part of the low limit with the L6081A differential giving me the 120-140 range. Finally, the T-T of the house/boiler would also be wired to the low limit of the L6081A, keeping the boiler at 120.

This would mean that the L6081A was breaking 24V on the high limit while both making 110 V and breaking 24V on the low limit. Can it do this? Is there a better way?

Tim

Unknown

Tim , what about

the Honeywell 8124 control ? You can use the T - T terminals to connect to the indirect aquastat in low voltage . Use the C-1 terminal to power the indirect's circ , and B-1 for the oil burner . The relay you currently have will power the burner separately on a call for steam heat only . With this control you can set the low limit at the minimum till there's a call for hot water , then it'll ramp up to the high imit . I do agree keeping some temp on an oil steamer is good practice too .

brucewo1b

I'm with Ron

but I would look at the electronic control L7224U, is more accurate and set your HL and LL and diferentials where you want Honeywell L224U

Tim Gardner

Thanks for the pointer. That looks promising.

Tim Gardner

oh no!

I thought I was going to be able to stay low tech by buying a good old fashioned cast-iron boiler. Now you're telling me I need one of those new-fangled techno-gizmos on it to make it run?

But thanks for the link. I will consider it. It looks like a nice controller.

Leo

Try Low Tech

Crank the Aquastat down a few degrees to keep a minimum temp on the boiler but high enough to make hot water. It is an experimenting process. Being this is a brand new steamer did it replace an old beast? That in itself will reduce oil consumption. If this doesn't work try having it wired back the original way. I work on oil and can tell when they have been shut off but your unit should run often enough to keep the harmful effects of condensation away NOTE for home readers this doesn't work for every brand. Now at my house the aquastat is set at 180 and I have a tankless coil on steam. It is an old beast and as the money is there I will up grade it. I'm like a kid in a candy store, I don't know what I want yet becazuse I work on and like so many different brands.

Leo

Leo

Tim Gardner

the new beast replaced an old

GM Delco with an internal coil. With the new beast and the new indirect my family is now able to waste hot water at much more mind-blowing rates. I'm expecting the increased usage to offset any savings from efficiency.

Also, that 180 degree water was great for rinsing the dishes, wasn't it? I can't do that no more. Now I"m down to 140 and now I have to scrub them clean.

Such is progress.