Questions about radiant heat system

[mx842]

You might be able to use the old burner control, as you mentioned. But be sure it is designed for line voltage on both outputs. Sometimes you can jumper the relay power supply terminals to power them with line voltage. From the factory, they might be set up to control a 24v circuit. Not sure why you need that control anyway as you cannot turn the heat exchanger pump off just because the room has gotten warm enough to turn off the thermostat. No room thermostat should be used here or you'll have run-away temps in the HX.

Your aquastat logic seem OK to me. Just be sure the bulbs are in the right places to sense the heat under any circumstances. I don't know why you need an additional controller. Just power the aquastats and they will turn on whenever there is heat. A simple wall switch that feeds them and provides a service disconnect should be fine. Since they are doing two separate jobs their run times will overlap but not start or stop at the same time. That's fine. I guess the only reason you even need two of them is to regulate the heat exchanger temperature more accurately and keep it hot to keep soot down. But I'm not sure that will make much difference. There is a lot to learn here.

Did everyone get through turkey day alright? I ate so much yesterday that I felt so full I couldn't take my usual after dinner nap and decided to go out and split wood for a couple hours and to work through it. The only problem with that was once I worked it off I was hungry again and had to eat one of the chocolate pies my wife made for the crowd we had over. It's amazing what a chocolate pie and a couple bud lite's will do to induce nap time.:licking:

The last post you made made it clearer as to what you were saying and now I know what you were talking about with regard to filling and purging the supply and return lines from the manifolds. I need to add another tee on the supply side to the loops for another hose bib. Before I was trying to fill the system by closing valve number 2 and opening hose bib number two then adding water through the hose bib on the bottom of the tank. I was having problems there because the T&P valve on the HX kept popping off, not letting me purge the manifold side completely. I tried it several ways with little success and today I plan on fixing that with adding that other tee and hose bib. The funny thing is I had that setup the way I had piped it the first time before I re-piped it the third time.:laughing:

Oh I wasn't planning on using that burner control I was just wondering if it would work. But the circulator and burner terminals are set up for line voltage. It does have a relay that switches to 24v but that is for the thermostat side of the control. When I was thinking about trying to use this control I was thinking about using an aqua stat rather than a thermostat to operate the control. Then I found this other high limit aqua stat I had on a shelf and decided to use it instead. I run into this a lot when I am doing projects using pieces and parts that I have on hand.

I have the aqua stat on the HX about dialed in. It cuts on the HX pump to the tank at 160 and off at 140. I've been watching it for a couple days now through many cycles and it seems pretty consistant. I may have to bump it up to around 180/160 once I get the wire run for the other pump and aqua stat for the loops on the other side but we'll see how it goes once I get this other tee installed so I can get the air out. It's been running a couple days now and I can tell that it has gotten rid of a lot of the air by itself. The pump sounds happier but I can still hear water rattling around the manifold supply lines at times. Oh and that 3/4 line I added between the supply and return at the manifold seems to be working nicely as I can feel it mixing the hot water with the colder return water by feeling the return pipe. Thanks for taking time to help me work this out. I took some pics yesterday when I was out in the shop but I have been too lazy to go back out there to get my camera so I can post them this morning. Hopefully I'll get over that half a chocolate pie I ate for breakfast this morning so I can get going soon because I still have two and a half pies to go before they are all gone. :dance1:

 

[Raspy]

mx,

Sounds like you're just about there. Good news.

I like aquastats and I'm assuming you're using the old ones with the bulb and the mechanical switch. They are extremely reliable. I have a number of them sitting around and like to use them in cases like yours. I'm also happy tour bypass is working as needed.

Since your setup is operating and clearing itself over time, maybe you don't need to cut into it again to install the purging tee. At least not now. That point was where I also thought it would be nice to install the fill regulator, so where did you end up putting that and the expansion tank?

What are the flow meters reading? Are you getting noticeable heat in the floor?

I hope you can tear yourself away from the chocolate pie long enough to send some pix and give a performance report! :laughing:

 

[mx842]

mx,

Sounds like you're just about there. Good news.

I like aquastats and I'm assuming you're using the old ones with the bulb and the mechanical switch. They are extremely reliable. I have a number of them sitting around and like to use them in cases like yours. I'm also happy tour bypass is working as needed.

Since your setup is operating and clearing itself over time, maybe you don't need to cut into it again to install the purging tee. At least not now. That point was where I also thought it would be nice to install the fill regulator, so where did you end up putting that and the expansion tank?

What are the flow meters reading? Are you getting noticeable heat in the floor?

I hope you can tear yourself away from the chocolate pie long enough to send some pix and give a performance report! :laughing:

I haven't been burning too hard the past couple days it's been pretty warm and the chocolate pie has been holding out pretty good. Yesterday I spent the day running a wire from the manifold room to the boiler room. Hopefully I will get it all hooked up today and working. I still can't see any movement with the little red disk in the flow meters but there has to be some flow. I'm still going to add that tee and hose bib because it wont be too much trouble doing it. There is still some air floating around so it might help to install that tee and bib so I can purge the system again......it can't hurt I don't guess.

Here are some new pics I took yesterday hopefully you can tell whats going on.

 

[mx842]

And a few more

 

[Raspy]

mx,

From the pix I can't see how the manifold pump connects to the manifold. It is pumping down and I'm assuming it feeds the bottom row with the flow meters. Are the white caps on the upper section all unscrewed as far as possible?

Is the system actually delivering heat to all the loops?

 

[mx842]

mx,

From the pix I can't see how the manifold pump connects to the manifold. It is pumping down and I'm assuming it feeds the bottom row with the flow meters. Are the white caps on the upper section all unscrewed as far as possible?

Is the system actually delivering heat to all the loops?

Yes they are fully open and yes when the pump is running I can feel hot water in each loop going into the floor.

Yesterday I finally got everything wired up and both aqua stats are now operating both pumps. I'm going to have to mess with it for awhile to find the sweet spot for both pumps. I also have to do some tweeking on the stove itself and figure out some draft control system and I may also put some kind of insulated shield around part of the stove to try and keep some of the radiated heat inside where it's needed. I would like to keep some of the heat that it puts out to help heat the back part of the shop where there are no loops but don't need all that it putting out.

 

[mx842]

Oh, and I forgot to mention that it seems that the little red disk are finally moving from the top of the glass in the flow meters. The disk are not showing much flow all seem to be showing around .2 gpm but I can see water in the glass tubes now and it's at a level about 1.0 gpm. I can open and close the restrictors on the upper manifold and watch the disk and the water level rise and lower as I open and close them.

I bought a couple new flow meters from pex universe and they are not like the ones that came with the manifolds. I went to replace one of the old ones but they didn't want to screw down into the manifold. They started but seemed really tight so I stopped and put the old one back on. I'm going to check with them tomorrow and find out if I got the right ones.

 

[Raspy]

mx,

You really don't need the flow meters. They are fun to look at and do give you an initial indication of what's going on, but the real adjusting should be done with temperature on the return lines just before they enter the return manifold. Grip each one with a couple of fingers and thumb. Remember that temp and go to the next one. With all of the adjusters open, find the warmest ones and turn them down a bit until, after some time, they all feel about even.

If you are not feeling much warmth on these lines, you should get a higher head pump.

 

[CalG]

Agree with Raspy, but don't be in a hurry to make adjustments. Give the floor an hour or more after the present pump starts running. Then observe inlet temperature before being critical of the return temp.
If there is not enough heat going INTO the floor, All the returns will be cold. ;-)

 

[Raspy]

Agree with Raspy, but don't be in a hurry to make adjustments. Give the floor an hour or more after the present pump starts running. Then observe inlet temperature before being critical of the return temp.
If there is not enough heat going INTO the floor, All the returns will be cold. ;-)

Exactly.