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EFM D-520 Furnace Control

Posted: Tue. Nov. 04, 2008 9:19 am
by army5102
Can anyone out there tell me if there is a furnace control for the D520 that will sense an out fire and shut the furnace down so that you don't end up with a fire box filled with unburnt coal ???? also if there is where can I get one I don't have a lot of out fires but once in a while I do get one. thanks in advance.

Re: EFM D-520 Furnace Control

Posted: Tue. Nov. 04, 2008 9:25 am
by Mark (PA)
Honeywell 6006A and / or 6006C model

A goes in a port on the boiler and the C version goes onto a pipe with a strap.

I have the C version. Works well. basically you set the water temp to shut down the stoker. SO if it goes below 120 deg it will shot off the stoker.

Re: EFM D-520 Furnace Control

Posted: Tue. Nov. 04, 2008 9:29 am
by army5102
What pipe does the 6006c strap on to ? and does it just sence the water temperature or does it have to go into the pipe

Re: EFM D-520 Furnace Control

Posted: Tue. Nov. 04, 2008 10:06 am
by Mark (PA)
You'd want to put it on a pipe as close to the boiler supply as possible so its getting the truest reading of boiler temp water.

it just straps onto the side of the pipe (doesn't need to go inside). Temp probe rests on the pipe itself. Senses the temp.

I believe Honeywell recommends going 20 deg less than boiler low setup with the C version. 5 deg lower with the A version

Re: EFM D-520 Furnace Control

Posted: Tue. Nov. 04, 2008 11:24 am
by stoker-man
If you go to efmheating.com and download the 520 manual, takes a minute or two, you can see the wiring diagram for this.

Re: EFM D-520 Furnace Control

Posted: Tue. Nov. 04, 2008 2:50 pm
by army5102
Thanks everyone for your help plan on doing it tomarrow

Re: EFM D-520 Furnace Control

Posted: Wed. Nov. 05, 2008 8:36 am
by slb04786
Army,

I use an L6006A aquastat for outfire detection. Mine has a SPDT switch which has 2 sets of contacts. 1 set opens on a temp drop and the other set closes n a temp drop. I use the contacts that close on a temp drop to supply AC power to my oil boiler. This works as an automatic switchover to oil as well as shutting down the stoker. Seems to work OK. You will need to wire bypass switches around the aquastat so you can bypass it when you are building a fire or want to supply AC to your boiler for testing/maintenance. I don't have a picture of my setup but I bought a single metal outlet box and a dual switch that was the size of an AC single recepticle. I used a nipple to mount the box on top of my aquastat and then ran my conduit out of the top of the box. Wire one of the 2 switches across one of the contacts on the aquastat and the other acros the other set of contacts. When the sitches are "off" or open the aquastat automatically controls the AC and when they are "on" or closed then it is in manual overide mode. I labeld my switches as Oil/Coal and Automatic/Manual for each switch. I hope I didn't confuse you too much.

I haven't tested the automatic fallback to oil yet as my coal fire hasn't gone out since I lit it 2 weeks ago. It did however work as planned to automatically turn the AC off to the oil boiler when the water temp in the coal boiler reached it's preset. I assume the reverse will work on an outfire.
Questions or comments are welcome.