Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Electronics => Topic started by: golffanman on October 22, 2013, 03:36:47 PM

Title: Heat from HX turning furnace fan on
Post by: golffanman on October 22, 2013, 03:36:47 PM
I hope this isn't a topic that has been covered before, I searched but could not find an answer. Started my boiler two days ago and I'm finding that the heat from the HX is turning my furnace fan on. The furnace is an older (1997) propane Intertherm in a mobile home. The exchanger is in the bottom of the furnace. I've disconnected the limit switch (one with the reset button) and the aux limit switch by the blower. I've also turned off the pilot. The blower kicks on and runs for about 1 minute to cool down the plenum. Behind the "control box" I'll call it, there is another limit switch by the fan switch. If I disconnect that one, the fan will not come on at all. I'm not a HVAC guy, but a pretty good DIYer. I know the heat from the HX is turning the fan on, but would like to find a way to let the thermostat take control. I appreciate your help in advance.
Bruce
Title: Re: Heat from HX turning furnace fan on
Post by: yoderheating on October 22, 2013, 03:49:37 PM
 You need a three way zone valve to only allow hot water into your coil when the thermostat is calling for heat.
Title: Re: Heat from HX turning furnace fan on
Post by: slimjim on October 22, 2013, 05:51:48 PM
WOW Yoder, NICE, I thougt I was the only one doing that, now we need to convince these guys to spend the money and effort up front in order to really reap the benefits of a properly installed system, NICE.
Title: Re: Heat from HX turning furnace fan on
Post by: willieG on October 22, 2013, 06:11:59 PM
i use a manifold system in the house and run to each "appliance" seperately and use a normal (i guess i'll call it that) 2 way zone valve to let water into my exchanger as my geothermal blower is designed to run 24/7 in low speed and that speed heats the house with the hot water rad.
Title: Re: Heat from HX turning furnace fan on
Post by: smitty33 on October 22, 2013, 06:19:28 PM
If your exchanger was on top of the furnace ahead of the blower, or a three way zone valve I have one on mine works great.
Title: Re: Heat from HX turning furnace fan on
Post by: Scott7m on October 22, 2013, 07:29:18 PM
WOW Yoder, NICE, I thougt I was the only one doing that, now we need to convince these guys to spend the money and effort up front in order to really reap the benefits of a properly installed system, NICE.

Really?!

You should some that I've done where the fan blower runs 24/7, on a real low fan speed setting, we'll use taco zone valves and they'll be controlled by the thermostat so that heat only enters exchanger when it's called for.  We set up a few ac's the same way.  Folks were blown way with the comfort level in there homes, I posted pics last year of one we did and the customer has called numerous times raving he can't believe it.   

I believe doing this is a great way to really balance heat through homes especially if they have high ceilings, it allows you to keep the home right at the desired temp 24/7 without having a warm surge every now and then that keep temps up.  Every room and every floor level will feel the same even warmth or cool. 

The guy who turned me onto this said folks love radiant heat, but most of them have never seen a hvac system that was actually installed correctly.  After doing a few and experiencing it myself, I have to agree. No heat rising and cooling the lower levels and such, just even top to bottom.
Title: Re: Heat from HX turning furnace fan on
Post by: yoderheating on October 22, 2013, 09:07:30 PM
 I put 3 way valves on all my systems. Some I do with manual valves and some with 24v valves. The manual valves are $25 and the 24v valves are $150 so people have a choice. Of course in the example given here you have to have a electronic valve. But the manual valves are nice for the low budget person who may want to run the outdoor furnace and the AC in the warmer parts of the year.
 
Title: Re: Heat from HX turning furnace fan on
Post by: golffanman on October 23, 2013, 06:29:15 AM
Thanks for the replies guys. I didn't know about the 3 way valves during my install. Looks like I've got some more work to do. Is there plumbing and electrical information on these valves I can research to change my setup?
Title: Re: Heat from HX turning furnace fan on
Post by: golffanman on October 13, 2014, 10:09:47 AM
Ok, here we are again, another heating season about or has begun. I just installed a zone valve in my plumbing system. I haven't fired up my boiler just yet, but I'll update this post as I progress.
Title: Re: Heat from HX turning furnace fan on
Post by: mlappin on October 13, 2014, 10:16:32 AM
Wouldn't a typical zone valve restrict the flow too much? Especially if a person was running Logstor or 1 1/4 for the increased flow?
Title: Re: Heat from HX turning furnace fan on
Post by: mlappin on October 13, 2014, 10:18:35 AM
A local guy that seems to work on everybody's heat or AC says if you are using either, to switch the fan control on the thermostat to manual and leave it there. We do that on the AC in the summer and it does seem to help.
Title: Re: Heat from HX turning furnace fan on
Post by: golffanman on November 07, 2014, 05:50:38 AM
Zone valve is working perfectly. Thank you to all of our hands on experts. That fixed my problem and the forum works again. Thanks again!