Help on Plumbing for Thermosiphon

TGMC wrote:S I M P L E . no need to complicate what has worked well

Adding a check valve isn't over complicating things. As mentioned it might not be suitable for smaller coils but if you have full boiler you might want to "check" it out.

Update: Got it finished up, and fired up last night. It didn't get as cold out as I had hoped but worked out good. Fired up at about 12:45 am checked temp this morning about 6:00 with a meat thermometer(only thing I have to check temp) and temp was about 115'. Not bad I think considering stove wasn't running flat out and probably didn't run at more than an idle for most of the time. It only had to bring the temp in the house up about 2' I added some insul. to the pipes today and will finish insul. Sat. morning. Hopefully this will help some. Also the 1st time I have run the stove using the chimney after taking off the DV. Was running about .02 on guage. Seemed to be putting out more heat. May be due to DV pumping some of the heat out of the vent. Had to run DV at full bore because the rheostat had a dead spot in it and wouldn't work except on high. Thanks to everyone for your help, it made this project much easier to complete with all of the input I have received.

Jeff

I'm glad to hear it all worked well.If in the winter you find to much hot water you can remove some of the insul on the gravity lines.

I STILL DON'T SEE ANY PICS OF YOUR SOLDER JOINTS! Jusk kiddin.

Did you use a tempering valve?
DON

Ok, now I have another question about the coil I have. It makes hot water fine and checking temp. out of tap with a meat thermometer it has been 135'-140'. This seems to be plent hot enough but I was wondering about recovery time. I know the thermosiphon method takes a while to bring it back to temp and the fact that it's not all that cold out yet so the stove isn't running full bore yet. I was wondering if having the coil bent out more ove the grate would decrease the recovery time by absorbing more heat into the coil. I will attatch a pic of current setup and see what you guys think. I know that once it gets colder out and the stove runs more it will help also. At any rate, this won't be something thats done until next summer. Thanks.

Jeff

Space out your showers and you'll be fine.

Most of the time, the coil is mounted directly over the fire, so the bottom pipe of the loop is about 6" above the grate... So yes as long as you are sure you won't damage the pipe, I'd bend it over the grate.

Greg L.

My loop is at the top of the stove. I guess the coil is about 11" from the grate.

Thanks, the coil works decent now and probably will be better the colder it gets and more the stove runs. I just wanted to ask if it would recover a little faster if it were closer to the fire. Thanks again.

Jeff

If you can bend it without stressing out the pipe I would do it but be careful. I would call the company and see if they have advice on how to bend it safely.

Here we go again, up until the other day we had only used the hot water in increments. Shower at night bath in the morning etc. I have been off this week and used more water than usual. Found out twice that the entire tank is not heating up even after approx 10hrs. Take a shower and used all the hot water in just a couple of min. Hot water is hot, and after that its just warm. Seems like the top of the tank is staying hot and lower in the tank is cooler. Do you think It's just not circulating fast enough. If so I could install a pump or any other suggestions.

Jeff

I missed this post lately.... sorry to see your back! *laughing* I'll vebture a guess that the pipe won't want to bend without heat... that is... acetylene and bring it red in two spots at once. My gut says it's thick enough that if you try to bend it cold you'll pressure the fitting and the side of the stove too hard. I'd even speak to the factory & ask. There might be some reason that it should be heated to bend it....like, if it's tempered you'll lose the temper.

As for the heating.... If you want to try a pump , try it. Is money no problem? Cheap: bronze pump, switch on wall. More: add aquastat. More: add four or five custom brazed dip tubes each a foot longer than the next and put thermometers to the bottom of each with thermal heat transfer paste. Heh heh heh....You could see the water temp at every level in the tank. *smile*. It would be interesting to know the temps at different levels in the tank. Of course if you add a pump, the temp would be even.

Even adding a pump might not give you more hot water. The tube in the stove is only going to transfer so many BTU's. Gravity tranfers them slower, but probably hotter. A pump would only mix the water. You might get some more heat, but I'll bet it wouldn't be a huge difference.

I wonder if you put wood blocks behind the coil so they push up against the back of the stove if you couldn't bend the pipe successfully. You need to get that pipe over the fire for sure.

This time of the year you're not running the stove that hot and will only get 3/4 of a tank or so.The thermosiphon slows down a lot because the temp in the pipe feeding hot water to the tank is about the same temp as the top of the tank and it slows down a lot.When you start running the stove hotter you will get hotter water and the thermosiphon will have more "power".If the tank wasn't insulated the hot water would cool slightly in the tank and start to sink letting the hotter water in the coil to keep feeding in the tank.Once you start running the stove harder you'll get more hot water volume wise and temp wise.
DON

Instead of bending, which would give part of it over the fire, how much trouble to move it?

Instead of bending, which would give part of it over the fire, how much trouble to move it?

Good point enter it from the side so it is right over the grates . Good thinkin' Freddy