Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Electronics => Topic started by: robash9608 on September 01, 2010, 04:32:34 PM

Title: Wiring Aquastat and fan relay
Post by: robash9608 on September 01, 2010, 04:32:34 PM
Just wondering how would I wire my aquastat and fan relay together?? I've bought a honeywell Well Immersion aquastat and an Enclosed Fan Relay(picture attached) . I also have a 110v/24v transformer, I was told that I needed that for the aquastat. I have no idea on how to wire this up so maybe one of yall would have advice on how to do this.. I have searched the net for a diagram on how to wire the relay but haven't had any luck.
Title: Re: Wiring Aquastat and fan relay
Post by: parkinspot on September 09, 2010, 07:34:21 PM
What are you trying to do exactly?  Are you planning to use the aquastat and relay to turn on your furnace blower and still use your gas for a backup?  If so then I have a much simpler solution.  All you need is a Honeywell 6006 (or equivalent SPDT) aquastat.  Place ther aquastat somewhere in the line coming from the boiler before it goes through any of your heat exchangers (this will give you a more accurate temperature reading).  First, connect the "W" line from your thermostat to the Common or "R" terminal.  Next, connect the "W" line from the furnace to the "B" contact.  Then, connect the "B" terminal to the Blower terminal on your furnace (Note: do not remove the existing connection from the thermostat to the furnace for the blower or you will not be able to manually turn on the blower).  The idea is that when the water from the boiler is above the preset temperature (most people use 100F) the "W" or heat signal from the thermostat will get routed to the blower terminal on the furnace, and when the water is below 100F it will get routed so your furnace will use the gas burner for heat.  This way you do not need separate thermostats.  I attached a schematic to help clarify.  Hope this helps
Title: Re: Wiring Aquastat and fan relay
Post by: robash9608 on September 15, 2010, 09:53:24 AM
Thanks for the help!!
Title: Re: Wiring Aquastat and fan relay
Post by: Pieman43130 on January 10, 2016, 11:55:07 AM
These instructions did not work for my setup.  Blew the board fuse.  I have an ecobee3 stat. 
Title: Re: Wiring Aquastat and fan relay
Post by: slimjim on January 11, 2016, 02:55:30 AM
I don't see why it wouldn't work? Perhaps somewhere the polarity got crossed? Maybe RSI or Shepard boy will chime in, they are both very good with low voltage, I typically do it with line voltage and a relay.
Title: Re: Wiring Aquastat and fan relay
Post by: mlappin on January 11, 2016, 11:53:51 AM
What are you trying to do exactly?  Are you planning to use the aquastat and relay to turn on your furnace blower and still use your gas for a backup?  If so then I have a much simpler solution.  All you need is a Honeywell 6006 (or equivalent SPDT) aquastat.  Place ther aquastat somewhere in the line coming from the boiler before it goes through any of your heat exchangers (this will give you a more accurate temperature reading).  First, connect the "W" line from your thermostat to the Common or "R" terminal.  Next, connect the "W" line from the furnace to the "B" contact.  Then, connect the "B" terminal to the Blower terminal on your furnace (Note: do not remove the existing connection from the thermostat to the furnace for the blower or you will not be able to manually turn on the blower).  The idea is that when the water from the boiler is above the preset temperature (most people use 100F) the "W" or heat signal from the thermostat will get routed to the blower terminal on the furnace, and when the water is below 100F it will get routed so your furnace will use the gas burner for heat.  This way you do not need separate thermostats.  I attached a schematic to help clarify.  Hope this helps

 :post:
Title: Re: Wiring Aquastat and fan relay
Post by: RSI on January 11, 2016, 06:03:57 PM
It shouldn't blow a fuse as long as nothing was shorted to the C wire.

There may have been some confusion due to the same letters in multiple places.

You need remove the W wire between the thermostat and furnace and  connect the W wire from the thermostat to the R on the Aquastat.

The B on the aquastat needs to connect to the W in the furnace.

The W on the aquastat needs to connect to the G in the furnace.

I usually disconnect the G wire on the thermostat so someone doesn't flip it to fan and overheat the house. If you want to keep it working, leave the G wire connected to both the furnace and thermostat as well as to the W on the aquastat.
Title: Re: Wiring Aquastat and fan relay
Post by: mlappin on January 11, 2016, 08:02:35 PM


I usually disconnect the G wire on the thermostat so someone doesn't flip it to fan and overheat the house. If you want to keep it working, leave the G wire connected to both the furnace and thermostat as well as to the W on the aquastat.

My wife did that to me shortly after i installed our first one. Was picking corn late one night and came in about three in the morning, about died two steps into the back door. Was real cold that night, had my Carharts on, a heavy hoody and insulated boots, house was 87 degrees. walked around after stripping opening windows and doors. Made sure in the AM I made it perfectly clear she was to never to touch the fan switch again.
Title: Re: Wiring Aquastat and fan relay
Post by: RSI on January 11, 2016, 09:07:16 PM
Lol.

I forgot to mention in the last post that some systems do need the G wire connected to the thermostat to work properly. If you disconnect it, try the backup heat to make sure it still works ok. Seems to be mostly heatpump systems that I have seen that need it.