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[Roger2561]

Hi all - Remember back in April I reported an annoying problem with the oil furnace running occasionally for about 30 to 40 seconds but then not again the remainder of the season?  Well, it did it again this morning at 3:30am.  The OWB has been running for a couple of weeks now.  The high set-point on the triple aqua-stat on the oil furnace was lowered to 150 so the oil furnace doesn't come on prematurely through the heating season.  I checked the water temp coming into the house from the OWB and it was 190+ due to the low heat load.  The temp on the oil furnace was ~180.  The fire in the OWB was going strong.  This spring I flushed the HX really good, until there was no more "junk" coming out of it.  This spring the oil furnace was serviced by a professional.  When the pro serviced my oil furnace I mentioned that I noticed the water temp in it would go well above 200 degrees.  The tech who serviced it said that's normal operation.  It bugged me to see the water temp that high (at one point it read above 230 degress) because I'd never seen that high before, but I really have to trust his knowledge of the system; I do not know everything.     He mentioned that the triple-aqua stat MAY be the problem, but he highly doubted it.  I let it go all summer (it provides me with my DHW).  It did not appear to boil the water BUT I'm no pro, so I'm looking to you folks for assistance, AGAIN, with this.  Thanks.  Roger 

[slimjim]

How old is it Roger, the issue may very well be the Aqua Stat or it's probe, there is a sure fire way to stop it from firing when the wood boiler is up to temp, would you like for me to post a drawing of how to accomplish the task?

[Roger2561]

How old is it Roger, the issue may very well be the Aqua Stat or it's probe, there is a sure fire way to stop it from firing when the wood boiler is up to temp, would you like for me to post a drawing of how to accomplish the task?

Slimjimn - I believe the oil furnace was installed in 1993/94 making it around 22 to 23 years old; everything is original equipment including the triple aqua-stat.  Please, post the drawing, I'm always willing to learn something new.  Roger 

[slimjim]

Here you go, if the TT wires are jumped out at the burner simply remove the jumper and attatch the two wires to each terminal, otherwise snip the burner power wire and wire nut the ends the the Honeywell Aqua stat wires, done! This allows the burner to fire on a call for heat if the wood boiler is below 140 degrees and above 140 it interrupts the signal or power!

[hondaracer2oo4]

That is how I have mine. I used the Ranco off my old hardy and zip tied the sensor wire onto the incoming owb line. I interrupted the burner motor power with the ranco if the temp coming in is above 150. If it drops below that the oil burner will kick on and take over. The oil boiler automatically kicks back out when I reload the wood boiler and the temp comes back above 150. I have a primary/ secondary loop system. The oil boiler and heating loops are on a secondary loop off te primary. The order of the loops is oil boiler, heating zone loop then flat plate hx then back to oil boiler loop. This allows me to send the hottest water from oil boiler to the heating zone first, then through the flat plate working to heat my owb water a little to keep that well above freezing. The primary loop pump only runs when the heating zone thermostat calls for heat. This keeps the flat plate hx from sucking a lot of heat out of the oil boiler constantly. Since the oil boiler is on a secondary loop it really shouldn't pull any out of it when the oil boiler pump isn't injecting water into the primary loop.

[Roger2561]

Okay, I'm back - running errands.   Thanks, Slimjim.  That drawing should help out a lot.  Do you have recommendations for a quality strap-on aqua-stat?  Roger   

[Roger2561]

Okay, in the pic, is the jumper to which you referred?  This is where the wires from the strap-on aqua-stat go, correct? 

[hondaracer2oo4]

Roger, while using the ranco probe zip tied to the incoming line and then insulating around it isn't "ideal" it works great for me. The temp probe reads about 20 degrees low but I just set the aquastat to 20 degrees lower. You can grab a ranco offline for as cheap as $40. The strap on mechanical aquastats are pretty pricy, like $80 bucks or so.

[Roger2561]

Roger, while using the ranco probe zip tied to the incoming line and then insulating around it isn't "ideal" it works great for me. The temp probe reads about 20 degrees low but I just set the aquastat to 20 degrees lower. You can grab a ranco offline for as cheap as $40. The strap on mechanical aquastats are pretty pricy, like $80 bucks or so.

Honda - please educate me on this; the Ranco has an external "probe" that's tied to the incoming water line from the OWB; the mechanical strap-on is just that, a strap-on device that makes physical contact with the water pipe from the OWB, correct?   

[slimjim]

Yes Roger to both questions, remove the jumper and connect the break on rise terminals of either aqua stat