Outdoor Wood Furnace Info
All-Purpose OWF Discussions => Electronics => Topic started by: pwdiver on February 06, 2016, 05:13:17 AM
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I had post earlier about a RTH8500D thermostat as I had stated not sure if possible would like to use the thermostat to control just the air handler for the heat and have the heatpump set as the backup heat not the Electric strip's if this is possible great, but I did not want 2 thermostat's like I had setup before. The current Honeywell RTH8500D is working great as it is setup now I just dont have backup heat if the boiler goes out. Any suggestion would be aprreciated. :-\
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Ive been in contact with Honeywell tech support on there thermostat's they say that none of there's will do what I want, I guess Ill have to canvas some of the other manufacture's about there product's I guess if I had to I could go back to 2 thermostat's but I dont want to. :bash:
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I'm surprised the Honeywell representative told you that. The Honeywell multi-stage YTH8320ZW100 has 3 heat and 2 cool source capabilities all on one programable thermostat which should do what you want.
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Thanks for the info I will look into that one. :pic:
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I want to chime in I went down this same road too (trying to eliminate second thermostat) and I also contacted Honeywell and was told no thermostats will do this. boilerman-- have you actually used one of these thermostats in this setup?
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My current Honeywell thermostat is a RTH8500D its working great for the boiler Im able to have this ramp the temp down at night and then back up in the morning. I f I have to Ill use this the way I currently have it and add another preferably Wifi for the heatpump like I had with the 2 wire thermostat I had previous. :D
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Here is how I've used the Honeywell 3 stage Thermostat I referred to. My dealer did not stock this thermostat, but ordered it from CB for me.
Just followed this wiring diagram illustration from the central boiler site. Here is the link to that diagram.
http://centralboiler.com/media/1106/c175.pdf
I purchased the DPDT relay switch (double pole double throw) from local heating supplier.
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I have a Honeywell programmable T-stat for my system but don't have the model number handy. It has multi stage and emergency heat capabilities. I used Geothermal for my primary heat source and LP for backup before I added my OWB (which was mainly for a new shed) but I decided to put all my heat loads on the OWB if I was going to keep burning wood. I didn't change anything regarding my T-stat with the exception of adding a strap on aquastat to my supply pipe set at 120 degrees which interrupts the 24 volt line to my geothermal contactor.
As long as the water temp is above 120 (or whatever temp you want) the T-stat cycles the furnace fan on as normal. It doesn't know or care that the geothermal isn't doing the heating. When the temp drops below 120 the contacts in the aquastat close and the geothermal kicks back in. Has worked flawlessly for me.
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My current Honeywell thermostat is a RTH8500D its working great for the boiler Im able to have this ramp the temp down at night and then back up in the morning. I f I have to Ill use this the way I currently have it and add another preferably Wifi for the heatpump like I had with the 2 wire thermostat I had previous. :D
The central boiler diagram that Boilerman posted with the summer / winter switch will fix the problem I mention a few days about screwing up the a/c. If you are using the programming and changing the temp a lot, it may start running your heatpump due to the temp differential between primary and secondary temps being exceeded. If you used an aquastat like Schoppy you would not have that happen.
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Thanks for the info I have more to think about now, thanks for the diagram Boilerman :thumbup:
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The nest can also be set for three heating sources, just use the * terminal for your third heat source. On mine * is used for the humidifier. From the menu you can also set G to be on for a call for heat with a heat pump.
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My brother called me today and wanted to get a single thermostat working. He has a gas furnace so a little simpler than a heat pump.
To get it to work the way he wanted, we had to go with this wiring: (Hopefully the columns line up below)
thermostat furnace
C C
RH RH
Y G
O/B Y (thermostat to energize on cooling)
W1 W
The reason we used this wiring was because he wanted to be able to manually turn on the gas heat. Using W1 and W2 it appeared to work but would have to hit the differential setting and he wanted to keep the hour delay setting before the gas furnace comes on.
It may be possible to get a heatpump to work by using 2 stage heat pump settings. I think it would require adding a relay and may not have an option to turn on the heat pump manually without raising the thermostat temp.
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My brother called me today and wanted to get a single thermostat working. He has a gas furnace so a little simpler than a heat pump.
To get it to work the way he wanted, we had to go with this wiring: (Hopefully the columns line up below)
thermostat furnace
C C
RH RH
Y G
O/B Y (thermostat to energize on cooling)
W1 W
The reason we used this wiring was because he wanted to be able to manually turn on the gas heat. Using W1 and W2 it appeared to work but would have to hit the differential setting and he wanted to keep the hour delay setting before the gas furnace comes on.
It may be possible to get a heatpump to work by using 2 stage heat pump settings. I think it would require adding a relay and may not have an option to turn on the heat pump manually without raising the thermostat temp.
I quite farting around with it, getting the Nest fooled into thinking my wood heat was a heat pump that is. Just about time I think I had it fooled it would still kick the gas furnace on just to be contrary. Installed a line aqua stat and took the W wire from the nest to the common on the stat, above 130 and the W gets connected to the G terminal on the furnace, below 130 the W wire connects to the W wire on the furnace. I may just manually adjust the aqua stat once in a great while to exercise the gas furnace once in awhile.
One distinct advantage to the two thermostat system is by a bit of programming I could have the gas furnace run once a day even if only for 5 minutes.
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Thanks for all of this info, I even contacted Nest and got a reply saying that there thermostat would not do what I wanted. Im still looking :thumbup:
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Thanks for all of this info, I even contacted Nest and got a reply saying that there thermostat would not do what I wanted. Im still looking :thumbup:
With the clever use of a relay or two and maybe an aqua stat it should work, Nest meant most likely directly out of the box it won’t do what you want.
I’m not overly impressed with who I spoke to at Nest or her supervisor about troubleshooting why I had an intermittent use of my humidifier. No matter how many times I explained normally my Orange wire which is connected to a relay to close the for the humidifier to kick on is hooked to the * on the Nest and it won’t do nothing now and hasn’t for a week, but if I disconnect the White wire going to the W connection and hook my humidifier wire to the W connection and turn the thermostat up, then the humidifier would kick on.
Took 15 minutes to get em to send me a new back plate.
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New back plate didn’t fix problem, wasted twenty minutes with em again today, I finally actually set them a picture straight from the Autoflo manual on what the orange wire is supposed to do on a call for humidification. They can’t seem to grasp the concept of an isolation relay. They also can’t seem to grasp the concept something is fubared in their product when I can hook my humidifier wire to the W1 terminal and turn the heat up then the humidifier works…..
Also can’t seem to grasp the concept of if the humidifier wire has zero voltage on it from the unit, it ain’t gonna work. No juicie, no workie.
I hate calling tech or customer support for any reason of any company.
Usually starts out with did you make sure it has power/fresh batteries/is turned on/hooked up correctly/etc etc etc.
After a few minutes of being treated like an idiot I usually interrupt them and tell them I’m not an idiot and don’t appreciate being treated like one, usually after repeating this two or three times they finally quite treating me like a mouth breather then something usually gets accomplished.
On an occasion or two I’ve handed the phone to the wife, told her this is so and so keep em occupied a few minutes, goto the fridge and power slam a beer, then go outside and take a power lap or two around the house then come back in and finish the torture session.
I do realize that sometimes people in tech support really do have to deal with for the lack of a better term, idiots.
The few times I’ve called Apple I’ve always had good luck, especially after a few minutes of discussing previous gaming PC’s I’ve built and why I used what I did.
However, how some people ever got a job in tech support just amazes me to no end.
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My brother called me today and wanted to get a single thermostat working. He has a gas furnace so a little simpler than a heat pump.
To get it to work the way he wanted, we had to go with this wiring: (Hopefully the columns line up below)
thermostat furnace
C C
RH RH
Y G
O/B Y (thermostat to energize on cooling)
W1 W
The reason we used this wiring was because he wanted to be able to manually turn on the gas heat. Using W1 and W2 it appeared to work but would have to hit the differential setting and he wanted to keep the hour delay setting before the gas furnace comes on.
It may be possible to get a heatpump to work by using 2 stage heat pump settings. I think it would require adding a relay and may not have an option to turn on the heat pump manually without raising the thermostat temp.
I quite farting around with it, getting the Nest fooled into thinking my wood heat was a heat pump that is. Just about time I think I had it fooled it would still kick the gas furnace on just to be contrary. Installed a line aqua stat and took the W wire from the nest to the common on the stat, above 130 and the W gets connected to the G terminal on the furnace, below 130 the W wire connects to the W wire on the furnace. I may just manually adjust the aqua stat once in a great while to exercise the gas furnace once in awhile.
One distinct advantage to the two thermostat system is by a bit of programming I could have the gas furnace run once a day even if only for 5 minutes.
Older thread but had to comment. Your comment got me thinking.
Benefit of two thermostats: Your gas furnace can be programed to fire up once a day for 5 minutes to keep the burner and igniter functioning. Mine starts hard initially each season. always has. Usually takes several cycles and sometimes a lighter to start it initially. No one knows why even though we have replaced igniter, etc.
Benefit of 1 thermostat and an aquastat: You can use a Wifi thermostat and control the temp from an AP remotely. also know at any time what the temperature is.
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Gunpowder, saw your last post about hard start ups on your gas furnace at the beginning of the season.
I don't know if you have LP or natural gas but it is actually quite common for this to happen. I have worked for a natural gas and electric utility for39 years servicing heating equipment also. If you do not have other appliances that use gas in the home during the off season or have a long run of piping to the furnace, the gas in the line can go stale (LP or natural).
There are also certain problems specific brands of furnaces have, we worked on all brands, that depends on your brand. Not sure what you have tried but let me know your brand and I may have some additional ideas for you.
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Gunpowder, saw your last post about hard start ups on your gas furnace at the beginning of the season.
I don't know if you have LP or natural gas but it is actually quite common for this to happen. I have worked for a natural gas and electric utility for39 years servicing heating equipment also. If you do not have other appliances that use gas in the home during the off season or have a long run of piping to the furnace, the gas in the line can go stale (LP or natural).
There are also certain problems specific brands of furnaces have, we worked on all brands, that depends on your brand. Not sure what you have tried but let me know your brand and I may have some additional ideas for you.
Furnace is in our nonprofit's nature center/office/restroom building. It is a Bard High Economy IH60D36B Furnace (highboy) with LP conversion. 58,000 BTU. Installed 94/95 time frame.
Trouble occurred at initial firing at installation. Installer put in a loop in the LP line thinking the LP was backing up-didn't work. Called the factory. They had no clue.
Over the years we have cleaned or replaced igniter, spark ignition controller etc. Still had to use a log lighter this year after pulling igniter out and cleaning it.
Has a gas water heater so should have had gas cycling. Just supplies heat to sinks/water closets so probably not large flow. That gas water heater heater has been out of commission for 4-5 years but this issue has been occurring from the beginning.
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Hi Gunpowder and Merry Christmas. I looked up the model you listed and it appears it uses a pilot, lit by a sparker, to light the main burners (3) via a burner cross over tube. Does the pilot light but not the burners or doesn't the pilot even light (or does one burner light but not all 3)? I have converted literally thousands of furnaces and all types of appliances over the years. Usually it was from LP to natural but the process is the same either way. One of the things technicians forget is that the air shutter needs to be adjusted in addition to changing the burner orifices, pilot orifice and regulator spring (or the entire regulator or gas valve if not convertible) and setting the manifold pressure once it is converted and running. When converting to LP the air shutters for the main burners need to be closed down for proper ignition and burning when lit (assuming they have adjustable air shutters). I have had to order air shutters for some furnaces I have converted as they did not come with them from the factory (all furnaces are manufactured for natural gas from the factory). When the main burners are on the flame should not be lifting off the burners and you should be able to see a defined inner blue cone above the burners within the taller flame itself. The flames on this type of burner should not sound harsh at all as compared to an in shot type of burner. The flames should also cross over smoothly to all three burners when set properly.
Not sure if all of these things have been checked but this is where I would start. Good luck.
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Schoppy,
Getting back to your question regarding my Bard that doesn't start dependably. Not old LP as it still does it today and has been running fro a few weeks now. eventually after cycling it eventually starts.
to answer your question of last winter, the auto ignite keeps clicking (with good spark) but never lights the pilot/burner. I have had 3 guys look at it including the installer back in '95 who even called the factory. Manifold pressure has been checked in past, pilot orifice has been changed out/over sized, undersized with no change. Shutter has been slid open to max. Slid shut to closed-no effect. If I give it a good blow I can get it to ignite sometimes. We have theorized gas is blowing too fast to get to pilot, etc but no change when we played with it.
It has cycled 3-4 times without lighting. So I waited till next cycle and blew a good burst of air in and it fired right up. Crazy.
Once lit, all rails are burning with nice blue flames out of ports.
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I have a Honeywell programmable T-stat for my system but don't have the model number handy. It has multi stage and emergency heat capabilities. I used Geothermal for my primary heat source and LP for backup before I added my OWB (which was mainly for a new shed) but I decided to put all my heat loads on the OWB if I was going to keep burning wood. I didn't change anything regarding my T-stat with the exception of adding a strap on aquastat to my supply pipe set at 120 degrees which interrupts the 24 volt line to my geothermal contactor.
As long as the water temp is above 120 (or whatever temp you want) the T-stat cycles the furnace fan on as normal. It doesn't know or care that the geothermal isn't doing the heating. When the temp drops below 120 the contacts in the aquastat close and the geothermal kicks back in. Has worked flawlessly for me.
Schoppy do you have any pictures or diagrams how you have this hooked up? This sounds exactly what I have been looking for.
I currently have a heat pump with electric strip heat at a backup but want to use my OWB as the primary.
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Sorry Gunpowder and morfem but I haven't been checking the forum very frequently with hunting season on.
Gunpowder-it can be a real pisser when furnaces won't ignite like they should. I have had a few that were real pains and it was just by trial and error that I resolved them. I have had to move or bend the ignitor electrode (carefully not to break it) to better contact the flame path of the pilot. On many gas valves the pilot flame is adjustable and I have had to do this to get it to light. The manifold pressure is important for the main burners but not for the pilot burner as it runs off line pressure ahead of the regulator on the gas valve. Sounds like your on LP so the line pressure from your regulator is important and not letting the pressure build during off cycles (typically locking up around 11 inches). This usually won't happen if there are other appliances on LP in the home but if the furnace is the only appliance it is a possibility when the regulator doesn't lock up properly. You didn't mention how your pilot sounds but it shouldn't sound harsh as this would be an indicator of too much pressure which makes it hard to light. Cycling several times before lighting can be reducing the pressure to a point where the pilot may light. This is a lot harder to diagnose when you're not sitting in front of the furnace. Try these if you haven't and good luck, let me know.
morfem-I do not have a wiring diagram for my setup but it is pretty simple. I use a strap on aquastat on my incoming line just inside the basement which opens on temperature rise (set at 120). I ran a pair of thermostat wires from it to the contactor for the geothermal unit which normally energizes the compressor and circ. pump. The thermostat wires are installed in series with one of the leads to the coil of the contactor. When the OWB is above 120 the aquastat opens and the geothermal compressor and pump do not come on but the furnace blower does which heats the house through the water to air coil I installed. Hope this helps, let me know if you have any questions.
Schoppy