A Matter of Control !

[zadwit]

I have the EKO-60 hooked up and running, supplying hot water to two 500 gal. propane tanks. Just prior to the entrance to the propane tanks, I teed off the supply(hot) and return (cool) lines to these tanks and feed a flat plate heat exchanger. From the heat exchanger I supply hot (glycol) to the inlet pump on the oil fired boiler. Just upstream of this connection at the oil fired boiler return water inlet, I have another tee for the return (cooler glycol) to the heat exchanger. When a thermostat in a room calls for heat and the zone valve opens, the circulator on the oil boiler go and feed the zone. I have connected additional wires from this circ pump to the 2 circ pumps on each side of the heat exchanger. I ran power to these heat exchanger circ pumps through a honeywell L6006 aquastat set at 80(f) so that the tanks need to be at least 80(f) of the heat exchanger circ pumps get no power. > 80(f) and the HX circ pumps get power if the oil boiler circ pump is running.
I measured the water temp flowing into the inlet side of the circ pump at the oil boiler and it is pretty close to the water temp in the 2 storage tanks. Still the oil boiler runs unless I set the honeywell L7124 aquastat on the oil boiler to 120 low and 140 high. Normally it is set at 180 low 200 high as it has an internal tankless heater.
(1) So, if I plumb the hot glycol from the heat exchanger to the OUTLET side of the oil boiler, how would I turn on the circ pumps when I needed heat in a room?If I plumb this way, and the room T-stat calls for heat, the zone vavle opens, the oil boiler circ pump runs, the heat exchanger circ pump runs and the room gets heated, however I am still burning oil which I am trying to get away from.
(2)I read in the EKO-60 RK-2001UA solid fuel fired boiler temperature controller manual, there is a way to shut off the oil fired boiler when the EKO-60 is running. It is talked about on page 7, paragraph 4.6 and also on page 10, UM-1 module. Has anyone connected this up so as to shut off thier oil fired boiler when the EKO- is operating?
(3)I am trying to keep the oil boiler system pretty much intact so that it can take over whenever the EKO is shutdown and the water in the storage tanks has cooled off. So I guess my question is, where do you tap into the oil boiler so as to shut the oil burner only off while the EKO is running and or the storage tanks are hot and then when they cool off, the oil boiler switchs back on automatically? IS this possible?I read nofossils sticky on simple pressurized system however I can't figure out how he turns the oil burner off. I think this is key to what I am trying to achive.
I have three zone, 2 of which are radiat floor heat so I can heat with lower water temp. One zone is upstair and is baseboard heat, however I can get by with lower water temp to that zone as well since it is a bedroom and cooler is better.
Enclosed is a drawing pretty close to what I did.

Thanks

 

[Nofossil]

Your situation is more complicated than either mine of they sticky. Looks like you're running the oil circ to get heat through the zones, and heating the oil in the process.

The zone valves have contacts which are usually connected to what I call the 'demand' input connections on the oil boiler controller. What I do is interrupt the zone valve contact closure so that the oil boiler doesn't see demand if either the wood or storage is hot.

If I have this right, the problem that you have is that you need the oil circulator to run any time your have heat demand. If you interrupt the zone valve demand signal, you'll have no circulation.

I suppose you could disconnect the oil circulator from the oil boiler controller and control it with a relay driven by the zone valve contact closure.

I don't have time to do a schematic now, but do I have the basic problem right?

 

[zadwit]

I think you have it. The oil boiler circ pump must run in order to get hot water to flow thru the oil boiler to the zones. I did discover something tonight. I have Honeywell L7124 triple aquastat on the boiler and it has the typical "low" and "high" limit settings. On the Low setting, if you turn it all the way counterclockwise, it says "disable" . I tried it and it shut the oil burner off, yet allows the circ pumps to run pulling hot glycol from the heat exchanger.
I have to go out of town until friday so will think about all this. I built a box and insulated the tanks with 2" blue foam and it works much better. The tanks are currently 185(f) and climbing. If a zone in the house calls for heat, it the circ pumps will ALL run and in the process hot water from the tanks will heat the oil boiler and I know from trying this the other day, the oil boiler only runs a bit then shuts off.
With a little work I can add a valve, a tee and plumb this so the boilers are in parallell. I can switch from series to parallell with the turn of a valve.
I still have the problem of DHW so I need to think about this . I may just get a superstor and pull hot water off the EKO to heat it and leave the tankless heater system intact so that the oil boiler heats dhw that way as well. Like you , I also have been thinking about an electric hot water heater. They cost about $500 for a 40 gallon heater here in Fairbanks. A 30 gallon Superstor is $1300 I think.
I don't mind the cost as I am looking at the long term picture with fuel oil hovering $4.00 a gallon, down from $4.66 this summer. Thanks for the response....

Mark