Plumbing that OWB

[myleakywooddoctor]

I have thrown together a straight tube heat syphon for my domestic hot water tank!

This syphon consists of a 4' 1.5" black iron pipe with a 3/4" copper pipe (tube) going straight up the center of it. At each end of my black iron pipe I have a 1.5 " female threaded black iron "T" reducing down at the top using a 1.5" male threaded to 1" female threaded black iron sleeve, then a copper 1" male threaded to 1" female soldered, then a copper 1" female to 3/4" female soldered onto my 3/4" copper tube.

Coming off at 90 degrees on each of these 1.5 " female threaded black iron "T" (top and bottom) I am reducing down using a 1.5" male threaded to 3/4" female threaded black iron sleeve and then a brass 3/4" threaded male to 3/4" compression fitting for the Kitec pipe from my Wood Doctor.

This setup heats my domestic hot water very quickly, but I found that the finishing touch was a mixing valve installed at the top to prevent cold water from the bottom of my tank from surging up threw the syphon and cooling the hot water leaving the top of my tanks every time I opened a hot-water tap! :-S

I installed my mixing valve with the hot side capped and the cold side delivering hot water! Now, when cold water rushes up my syphon, the valve shuts down allowing 100% hot water to be delivered when called for! :coolsmile:

No advise was provided by the Wood Doctor Dealer on any of this!

I will put up another picture showing how I piped the bottom end of my straight tube domestic Hot water syphon so that I could just open a valve to feed water directly into my outside wood furnace thereby topping it up when it starts running low on water, which is very often of late I'm afraid :down:


Leaky :smirk:

 

[myleakywooddoctor]

In this pic of the bottom of the syphon, you can see that the 3/4" iron to the syphon and the 3/4" copper to the bottom of my hot water tank are separated by one 3/4" brass ball valve.

When I open this valve, water comes out the bottom of my Hot Water tank and straight into the boiler feed lines to the outside jacket of the syphon.

So, I just have to open the valve for about a minute, to top up my boiler which could be anywhere on my property, from the nice warm comfort of my basement! :coolhmm:

The 3/4" iron line has a screen clean out in-line and the 3/4" copper line has a one-way valve in-line to prevent boiler water from moving backwards into my domestic hot water tank!

The orange Kytec line you see is where my Wood Doctor boiler water normally feeds in to the bottom of the syphon!

This sure comes in handy if you own a Wood Doctor! :gulp:


Leaky :smirk:

 

[Eric Johnson]

That's an interesting variation on a classic sidearm heat exchanger. I have one on my system. I avoid the problem of cool water getting in the way of the flow of hot water by using the sidearm hx to constantly circulate hot water into the water heater. Cold water enters the water heater through the regular cold water feed tube, and I draw it off of the regular hot water supply tube. Here's a diagram.

Sorry to hear about your leaky OWB, by the way. Continually putting oxygenated fresh water into the system is going to accelerate any corrosion that may be going on now. Have you tried Boiler Stop Leak or some other liquid remedy?

 

[myleakywooddoctor]

I have a thin plate heat exchanger separating the open and closed side of my heating system with fine wire mesh screens on either side of it to stop it from getting clogged!

I don't think puting a stop leak solution in my boiler water would work too well for me! :gulp:

Besides, Wood Doctor would probably invalidate my warranty, not that it matters! >:-(

Leaky :coolsmile:

 

[Eric Johnson]

If you have a warranty, then why don't you have a new boiler?

You can isolate the boiler and run stop leak through it until the leaks quit, then drain it and start with fresh water if you're worried about the flat plate hx getting fouled.

Not that stop leak is a great thing to do, but in my mind it beats living with leaks and a constant influx of oxygenated water.

 

[Sting]

I don't see any thermal protection limiting temperature out to code of 125 degrees!

I see you rigged the protection valve to stop cold Quote: I installed my mixing valve with the hot side capped and the cold side delivering hot water! Now, when cold water rushes up my syphon, the valve shuts down allowing 100% hot water to be delivered when called for!

Am I missing something?

 

[myleakywooddoctor]

My syphon also has a zone control on the boiler loop to shut the outer jacket loop off when my DHW tank comes up to temperature! So my DHW does not over heat!

My mixing valve is not installed as a mixing valve. It is installed to serve another purpose and that is simply as a loop shut off (when cold water rushes up the inner tube). The volume of DHW in the 3/4 copper inner tube of the syphon is very small and does not pose any risk. :coolsmile:


Leaky