Econoburn Overheat relay vs. Dump Zone

I was sold a normally open zone valve with the sale of a used econoburn. Previous owner said it was wired to the over-temp factory leads and I think he had it wrong, using that valve as a "dump zone".

Does the Econoburn need not only a normally open valve for a loss of power dump zone but also a normally closed valve for use in an over-temp situation?

I finally powered up the the econoburn for the first time and checked voltage across the terminal block and I was not getting 24v from the over-temp relay. Under the assumption from the previous owner, I thought the over-temp continiously provided 24v to the valve to keep it closed and during an over-temp/power failure, it cut the power and the valve opened.

Since I don't have an Econoburn I can't say for sure BUT in a general sense, yes.

Now those two things can be the same, the overheat dump and the power off dump, but you would need both "features".

K

The no power dump zone is usually a normally open valve which is wired Independently of the boiler controller. My Econoburn has a safety aqustat that is used to interupt the fan if there is a over temp. I think it was preset at 205. The controller puts the fan in low at 5 degrees before setpoint and off at the setpoint. The boiler also has connections to energize a dump zone if the set temp is hit I would have to look it up.

This info is dependent on which controller you have. I have the newer style DFD controller.

gg

I wonder why Econoburn didn't put a relay to cut the power in an overtemp situation thus eliminating the need for both.

Does anyone know if the factory overtemp lead is for a 120v or 24v zone valve?

They are two different things. The no power dump is for controlling temp creep if power stops with fuel in the boiler.

You could use a relay to simulate that condition with the over temp circuit, or use the over temp to dump heat to a heating zone.

My controller says over temp circuit 115v

gg

I understand the need for both and I'm glad I looked into it a bit further. I have a transformer powering the three zone valves to the house. I'll wire the Normally open valve for the loss of power dump zone off this transformer. However, can I just pruchase another 120 primary, 24 secondary transformer for the overtemp relay and wire to one of my zone valves?

I can't help you with that, hopefully someone else can chime in.


I was going to use a RIB to kill the power to my no power dump zone if the over temp ever activated. The fin tube with a pump running would dissipate alot of heat. My 1000 gallons of storage protects me from over temp, storage will absorb output. I have a paralell pump installed for safety/redundancy.

gg

Did you get manual with boiler? It is available on their website. I have the newer DFD controller. If you need to determine which one you have I might be able to help.

gg

No, i didn't get a manual with the sale. I'm going off the online manual here.
http://www.woodheating.ca/EBInstalMan.pdf

I don't see 115v for overtemp relay. However, electrical schematic shows it in series with power to the circulating pump(s) so i should have caught it then. Not sure if I have the DFD controller. Not sure if they're the same with the EBW-150?

The controller depends more on the age of boiler vs model.

Gg

Typically, an over-temp circuit on a boiler would close when temp rises to setpoint, and send 24v to open a zone valve, which would in turn close it's internal end switch to close another circuit that starts a circulator. That is, it acts the same as a thermostat on your wall when it calls for heat. However, I have no knowledge on the EB circuit - does it have an adjustable setpoint? Most do in an aquastat? You could just turn the setpoint down after you get your boiler up to temp until the setpoint gets down to the boiler temp, then meter the current across the contacts that should have just closed & see what you've got. Do this before wiring anything up to it.

A dump circuit is completely separate & different, and as mentioned above the NO zone valve would just be fed a constant separate 24v current - and when the power goes out the valve opens letting water flow by convection.

So, it sounds like it might have been wired up wrong before?

I didn't think the above through very good.

I think some setups do use just one control for overheat & dump. That would be a break on rise aquastat, wired to a NO zone valve. When either the stat hits setpoint for an overheat (say 200?), or the power goes out, it would cut power to the NO zone valve. Then if it was an overheat, that would also start a circ via zone valve end switch, or if it was a power outage, the flow would circulate by gravity.

That might not help figure out what's wrong with yours.

The more I think of it, the more I appreciate the design. I belive the previous owner did have it wired incorrectly. And I'm glad I found this out now and not after it running. The design makes sense. A way to get rid of the heat without losing all those excess BTU's. And I'm going to have a seperate loss of power dump zone so I'd rather dump the hot water somewhere useful while still having power. I think the easiest way for me is to order a transformer and wire the overtemp relay to one of my existing zone valves. In doing so, it does trigger a circulator to provide flow through a zone. The overtemp relay is internally controlled by the Econoburn. I'm not sure what the temperature setting is. I'll have to send an email to confirm but I would guess it's around 200 degF? I'll also power the N/O zone valve for the loss of power dump zone off the existing 24v trasnformer feeding the current zone valves.

Sounds like you are on the right track.

Here is a picture of the DFD controller.




gg

Nope. I have the older style controller. Note sure what the difference is?

Yes I have 2 dump zones on my eb 150 . The over heat temp one is 120 volt normally closed ( so when the controller hits a setpoint it opens up the 120 volt valve.) I have a normally open 24v valve hooked up so heat can circulate by gravity in a no power situation.