Indirect DHW tank up and running tons of hot water Oil Free!

[mpilihp]

I got our Indirect DHW tank up and running this past weekend. Its been heated with wood every evening and plenty of hot water the next morning, even the next evening it still had enough for several showers.

Two runs of 3/4" pex supply the heat loop and the white pex is the DHW side.

With this setup its cut the time the oil boiler runs to keep DHW and itself hot in half.
Next on the list now is to hook up relays to keep the oil boiler from running till a zone calls for heat!

~ Phil

 

[Nofossil]

Sounds great! Make sure you use a mixing valve on the hot water tank outlet if there's any chance of getting it too hot. Once you do that, of course, you can overheat it on purpose to make it last longer. I heat mine to 160. With preheated water coming in, I can get 3 days out of a 40 gallon tank - and that's with a teenaged daughter.

 

[MrEd]

Is that 3 people, taking a shower everyday? and you get three days out of 40 gallons? thats great.

With a family of 6 I will probably go with a 60 or 80 gallon tank, but I can see how the supercharging of the temp would really stretch out those gallons.

 

[mpilihp]

Hi Nofo I have the 3-way valve you recommended, its in the upper left corner, set at 120 deg

Because of how my system is plumbed, when the wood boiler circ is running its heating the indirect dhw tank, pump on dhw is only for when the oil boiler needs to kick on and heat it. So the tank gets up to 170 but as the wb runs and cools it goes down to about 160.

So you get with one firing 3 days of showers for 3 people with pre-warming your water right? I have the opportunity to get my hands on an 80 gal elect hot water tank and was wondering if I could set that up in front of my indirect dhw tank to pre-warm the water using a side-arm on the return temp water to the wood boiler would that be worth the effort and space it will take up??

In the summer I would look to do it with some form of quick and cheap solar like you talked about in another link IE black hose on the roof...

 

[wantstoburnwood]

Ok guys explain this to me . I don't have any hot waterin the morning as I just heat domestic with the coil in my oil boiler which is heated by my woodl boiler. I have a 40 gallon electric water heater for the summer. Diagrams would be great.

 

[mpilihp]

Do a search on this forum for 'sidearm' there are several threads that discuss how to build and set one up with a DHW tank. Basically would allow heating of the water in an electric hot water tank with the wood boiler hot water. I considered doing that but I could not come up with an automatic way for DHW to be supplied by my oil boiler when the wood boiler doesnt get run.

The Indirect DHW tank is an easier solution. You may be able to find one cheap like I did, its a cheap brand, armotrol boilermate I bought used for $250, no where near as good as the name brand ones but about 1/4 the cost.

~ Phil