Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Plumbing => Topic started by: chiselchain on November 30, 2013, 07:39:05 AM

Title: running out of hot water
Post by: chiselchain on November 30, 2013, 07:39:05 AM
i have a 38inch side arm exchanger. but it seems like im running out of hot water pretty quickly. the water heater is 2 years old and when I hooked up the side arm up a bit of lyme came out of the drain. now I turned the water heat on and it seems to have plenty of hot water. think my water heaters plugging up?
Title: Re: running out of hot water
Post by: hondaracer2oo4 on November 30, 2013, 08:16:36 AM
Is this a new symptom for you? I too have had hard water issues in the past. Once in a while I use  to open up the bottom drain which was T'd off of the bottom feed for the sidearm and drain out a bunch of lyme which would plug up the bottom feed. I have installed a water softener now which has taken care of the issue. I also pump my side arm now as well.
Title: Re: running out of hot water
Post by: chiselchain on November 30, 2013, 08:26:30 AM
this is my first year with my boiler. what do you mean by pump your side arm?
Title: Re: running out of hot water
Post by: hondaracer2oo4 on November 30, 2013, 08:36:13 AM
I have a pump on the bottom intake that is thermostatically controlled. when the water in the take drops below 145* it turns on and pumps water through the sidearm for a quicker recovery. It works OK. I was hoping for faster recovery times. The problem with my sidearm when it was only thermosiphon   was the top of the water tank would be 180 while the bottom was at 60. I would get probably 20 gallons of 110* water out of it and then it would drop. My side arm is only 12 inches with many small tubes inside for the heat exchange. I would like to try one of the long sidearms that is just a tube inside a tube. Don't know if it would work better. It takes me a few hours still to bring the hole tank back to 145* even with the pump. I have the pump throttled way back with a ball valve. Doesn't move very much water very quick but is constantly moving it until it reaches 145*.
Title: Re: running out of hot water
Post by: chiselchain on November 30, 2013, 01:50:38 PM
I don't suppose it would hurt to turn my water heater back on with my boiler still running to it would it?
Title: Re: running out of hot water
Post by: cantoo on November 30, 2013, 02:41:36 PM
I have a stainless sidearm 3/4" line inside a 2" pipe (I think) supply is a 1" line coming straight from my owb approx 40' away. Hot from owb goes in the top of the sidearm, heater is set up to thermosiphon and we have a mixer valve installed. I connected the sidearm into the top side of the heater using a T for the pressure relief valve. Owb is set to 155*.  It works really well and we haven't had any issues with running out of water. If you are running out of water maybe something isn't setup right. Did it ever work right?
 I assume he means that he has his sidearm connected to the pump instead of thermosiphon to move the hot water.
 You can turn your breaker back on, it won't hurt anything. Some peope still leave their electrical hooked up they just drop it a few degrees so that the owb does most of the heating, the electricity is just a backup or for quicker recovery when using a lot of hot water. I have a 20 plate exchanger on my other house and it works good too, the more water you use the hotter it gets. ( mixer valve keeps water temperature from scalding though.
Title: Re: running out of hot water
Post by: bikeralan on November 30, 2013, 02:49:47 PM
I had a sidearm on my stove at our previous house and it never did work quite right, fiddled with it constantly.
I now have a 20 plate exchanger and love it, no problems.
Title: Re: running out of hot water
Post by: chiselchain on November 30, 2013, 02:56:23 PM
it sounds like the same side arm I have but I have my supply line from my boiler going into the bottom port of the side arm. would this make a difference? your set up sound the same as mine(T with pop off and mixing valve). its 60gallon water heater and by the time we give the kids theyre bath and my wife takes her shower its luke warm water left over for me! lol.
Title: Re: running out of hot water
Post by: cantoo on November 30, 2013, 03:14:31 PM
I really don't think it makes much difference but would be easy to change out just to see if it helps. Mine is only 40 gal and usually just 2 of us but hot water hasn't been an issue even when we had lots of people over. I have a pretty short run though and very little heat draw so maybe my water is just hotter in the tank. Do you have insulation on your hot water lines? I can hardly hold my hand on the pipes.


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Title: Re: running out of hot water
Post by: chiselchain on November 30, 2013, 03:26:10 PM
looks pretty much the same way I set mine up. my underground pipes are three wrap but in the house is just pex. when I touch the side arm ou cant hold your hand there very long either. maybe im just using to much water.
Title: Re: running out of hot water
Post by: cantoo on November 30, 2013, 04:13:31 PM
Really though it should be the same as electrically heated water. Only difference is you are heating it with water instead of electricity so the volume of water should be the same. Maybe you need another storage tank so that your incoming cold water is at room temperature instead of really cold. This would help your recovery times as you wouldn't be raising the temperature nearly as much. Just plumb in an old water heater tank or a pressure tank to your cold water supply and the water will be at room temperature to feed your hot water tank. Can't hurt.
Title: Re: running out of hot water
Post by: mikemike on November 30, 2013, 07:18:32 PM
In pic #4 is that galvanized pipe you are using?
Title: Re: running out of hot water
Post by: cantoo on December 01, 2013, 07:43:54 PM
There is a 3" galv nipple on the hot water tank, the other one is after the relief valve so no problem. I have a brass one to replace the one on the water heater just haven't changed it out yet.
Title: Re: running out of hot water
Post by: chiselchain on December 02, 2013, 03:58:46 PM
whats wrong with using galvanized?
Title: Re: running out of hot water
Post by: cantoo on December 02, 2013, 04:33:18 PM
Chisel, I think it has something to do with corrosion in domestic water. Also some people say that using different metals can cause issues too, copper, brass and galv or even black pipe on the same system. You know the old ebony and ivory story. My old water system was all galv pipe so not sure it matters much anyway. My owb is stainless so not sure if it's a problem anyway. TSC had their brass on sale for half price which was close to galv regular price so I bought all brass fittings.
Title: Re: running out of hot water
Post by: brandontravis on December 02, 2013, 06:06:01 PM
i have a portage and main optimizer 250 boiler apx 100 ft from sidearm exchanger i have the supply going to the top of the sidearm exchange with 1" pex then i have 3/4" copper from top sidearm exchange to alt pop off place on top of 80 gal hot water tank. the temp going into tank is about 175 degrees coming out of tank is about 90 degrees after 1 shower its about 60 degrees coming out. i had a taco 009-f5 pump and taco 5004-c2 mixing valve, i removed the mixing valve and replaced pump with a taco 2400-20-wb pump and still have same problem. any ideas i am running out of options?
Title: Re: running out of hot water
Post by: cantoo on December 02, 2013, 06:31:21 PM
Brandon, I don't know pump numbers or speeds but maybe you are moving the water too fast? It will take quite awhile for 80 gals of water to get hot but once hot you should have lots. My water going in is at 160 at the max and coming out(after mixer valve) is max 120. Can you post pics of your setup? Something must be plumbed wrong to loose that much heat that quick.
Title: Re: running out of hot water
Post by: brandontravis on December 02, 2013, 06:56:40 PM
 Here are some pics the supply hooks up at top of sidearm exchange the bottom goes to my supply for furnace exchanger

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Title: Re: running out of hot water
Post by: hondaracer2oo4 on December 02, 2013, 07:10:40 PM
I am not a good reference on this thread seeing as how I have had my own issues with my shell and tube sidearm but I do have a question about how you plumbed it. I have always read that with sidearms you want to ideally go into the side of the tank as to not force the water to fall back down into the tank after its been heated. Whats the reason that you didn't go in through the blow off valve on the side of the tank?
Title: Re: running out of hot water
Post by: cantoo on December 02, 2013, 07:18:06 PM
Brandon, I can't tell from the pictures but it looks like your hot go into the center of your hot water tank at the top. Some heaters have a diptube on the cold supply inside that runs to the bottom of the tank, maybe your's is like this? I hooked mine to the pressure relief value outlet incase mine had this tube.
If you look at this picture you see where it is labelled "dip tube" this would stop the water from thermosiphoning properly.
 If you look at my pictures you will see in the last picture where I hooked the hot on the sidearm to the T at the pressure relief outlet.
Title: Re: running out of hot water
Post by: cantoo on December 02, 2013, 07:28:30 PM
Brandon, this quote is from another site. "If you plumb into the hot water inlet DO NOT extend the heat exchanger any higher than 3-4 inches above the hot water heater. Try to stay as level as possible to the top of the tank. Anything higher than 3-4 inches will disrupt the thermosiphon and the heat exchanger may not work. Important Tips

Newer hot water heaters have an anti syphon valve installed in the top of the hot water exit. It is a blue plastic valve that needs to be ripped out using a pair of needle nose pliers.

 If you do not remove the anti syphon valve the thermosiphon process will not work. If the sidearm heat exchanger is plumbed into the pressure relief valve, the blue anti syphon valve does not need to be removed.

Use as few angles and turns as possible when plumbing in the heat exchanger. Keeping the heat exchanger between the top and bottom of the water heater and using a limited number of turns will assist the thermosiphon process."
"

It looks to me like you are more than 8" above the top of the tank? They recommend hooking into the pressure relief with a T the same way I did.
Title: Re: running out of hot water
Post by: brandontravis on December 02, 2013, 07:49:10 PM
i dont know much about the tank but the place on the top is a alternate place for pop off valve so i thought it would work the same as on the side. all the bends are when i first installed sidearm i didnt realize it was right in front of the tanks heating coils so as a quick fix i moved it over never thought to many bends would cause a problem but that will be my next step in trying to fix.