OWB + Oil Forced Air furnace

[Mb80]

New to the forum, but after looking around...I'm glad I found it! Wish I would've found this years ago!

On to my question/issue...

Heatmaster G200s plumbed through several grundfro pumps to a hot water coil then to a heat exchanger in the plenum of my oil Thermopride. I currently have a honeywell aquastat on the feed line from OWB before the HE which is wired to a fan relay inside the oil furnace. This is all wired to a heat/cool 2 stage thermostat (which I hate). Having issues getting the oil furnace to fire when the OWB isnt burning. I'm guessing because the aquastat is in the equation...

I would like to wire up a second thermostat and get rid of the 2 stage thermostat ( I do not have a/c).

If I were to use a second thermostat, can I wire the aquastat in that scenario to only run the fan for the OWB if the temp on the aquastat is high enough? That way the fan wouldn't run if the fire was out, and the oil furnace would fire once the house temp drops below set temp? I'm assuming I would have to run a second tstat wire?

Would this get rid of the issue of the fan continuously running if the OWB fire goes out? The fire rarely goes out throughout the winter (I work in the oilfield and sometimes dont get home early enough to keep it burning), but it does happen...

Any help is GREATLY appreciated!

 

[al-k]

Welcome to the forum, wish I could help.

 

[H-Ranch]

There are several system wiring diagrams on Central's website that may help. Not sure if they show one that will do what you want.
https://centralboiler.com/explore/furnace-installation/

 

[Iaff113]

Not sure if this would help but couldn’t you put a thermodisc some where on the furnace to cut it off and on for whatever temp range you want?


Sent from my iPhone using Tapatalk

 

[rancher2]

Mb80
Welcome to the forum. I am doing what you want to do on my Garn. I have a propane furnace would be the same set up as a oil furnace. I run two thermostats. One runs the propane furnace and the other runs the wood boiler {Garn} I have another relay down in the blower compartment on the furnace that is hooked to the Garn's thermostat to turn the blower on and off. Relay is wired to the green terminal on the furnace board to run the fan. The Garn's thermostat also turn's on the pumps to get the water moving when there is a call for heat. Now here comes the part you want to do I also have a Ranco brand temp controller hooked up that the probe senses the water temp on the Garn and if its down to 120 and won't heat the house it inter locks the Garn's thermostat in the house and won't let the furnace fan keep running and as the temp in the house drops the thermostat for the propane furnace turns it on and keeps the house warm.
I used to have the same problem as you when I was working in town I would be gone 16-18 hours at a time and my Garn would be out of wood so the propane would needed to run until I got home to get the Garn going again. Sorry I don't have a drawing of the set up. If you know a little about wiring and controllers its not hard to set up what you want to do.