greenwood 100 Hot water

[steam man]

One important tidbit-you should use a bronze pump for the dhw side. I use a TACO 006 model to do pretty much the same thing. The problem is they are more expensive.

 

[leaddog]

I think that if you get your tank clean so the side arm can work that you will be happy. I put one on my stepsons,theyare a family of 5, and use a LOT of hot water and have never run out. With the boiler water HOT you can tell if the sidearm is working or not because the top hot water pipe going into the tank will get hot right away. If it doesn't you aren't getting a flow.
leaddog

 

[antknee2]

Some newer style hot water heaters have a built in mini anti siphon device in the 3/4'' male nipple , cold in , hot out , on top of the water heater . They cause all kinds of problems , might be worth looking into . Anthony
PS: also called heat traps.

 

[Ncountry]

We have a sidearm heat exchanger hooked up to a 50 gallon hwt and we never run out of hot water.Something you may want to check is how the top of your loop is constructed. The domestic water loop should come from bottom of tank and then travel upwards into upper part of tank .Due to the fact that my sidearm was too tall for the tank I had to elbow back down to hook to the upper part of tank.Needless to say it did not work initially .Had to install a bleeder at top of loop to remove trapped air and allow convection.

 

[heaterman]

My favorite way though not the least expensive, works seamlessly with your existing system and provides gobs of hot water. We simply pipe a 30 gallon SuperStore indirect water heater in front of the existing unit and let it reach whatever temp the boiler is running. To prevent scalding we pipe a thermostatic mix valve between the wood fired indirect and the existing water heater. This has the effect of increasing the capacity of the 30 gallon tank by a large amount dependent of course on the water temp from the wood side of the system. If you choose to let the wood side go out you don't really have to bypass the indirect as it will just act as a tempering tank to a small extent by allowing the 30 gallons of water to come up to room temp before entering the existing unit. We don't even use a circ on this setup in most cases. Just a globe valve or circuit setting valve in the main loop to induce flow through the indirect coil. A setup like this ensures that the existing water heater always "see's" preheated water and functions only to keep itself warm.

 

[steam man]

Some newer style hot water heaters have a built in mini anti siphon device in the 3/4'' male nipple , cold in , hot out , on top of the water heater . They cause all kinds of problems , might be worth looking into . Anthony
PS: also called heat traps.

Anthony has a point here. I assumed your sidearm must have worked at one time. However, if your tank has a heat trap built in I can see how it could restrict convective flow back to your tank. I have them built into the two Vaughn tanks I use. They are more like a loop from the top of the tank that goes to an outlet 1/4 way down the side to "trap" the hot water in the top of the tank. I actually removed the heat trap on my solar tank but that was just to access the tap on the top of the tank. You may be able to repipe the hot water tank so as to install a loop for a heat trap after the sidearm connection. Just a thought.