Heating DHW

[forestrymike]

I have been mulling things over in my head now for a while, and have had one question I just can't seem to answer on my own. I am planning on a new boiler for coming heating system, but don't expect to be able to have storage for the first winter (mainly the $$ required). I would like to be able to heat my DHW with the boiler. I understand that if the boiler is running I would be able to get lots of water with a sidearm on my current 40 gal electric HWH. But, if the heating system in my house is not calling for heat, and the boiler is not running, is there still a way to get DHW if the system calls for it. I have thought about adding one or two extra HWH heaters to have some stored DHW, but don't know if this would work. Any suggestions, or maybe I'm just not understanding completely how the system works?

MA

 

[Nofossil]

I have been mulling things over in my head now for a while, and have had one question I just can't seem to answer on my own. I am planning on a new boiler for coming heating system, but don't expect to be able to have storage for the first winter (mainly the $$ required). I would like to be able to heat my DHW with the boiler. I understand that if the boiler is running I would be able to get lots of water with a sidearm on my current 40 gal electric HWH. But, if the heating system in my house is not calling for heat, and the boiler is not running, is there still a way to get DHW if the system calls for it. I have thought about adding one or two extra HWH heaters to have some stored DHW, but don't know if this would work. Any suggestions, or maybe I'm just not understanding completely how the system works?

MA

One soultion would be to add an indirect DHW tank in series with and ahead of your existing tank, and set it up as a zone on your boiler, set at a somewhat higher temp than your electric. Or just use the indirect - that's what I have, and it works great. I've added a few bells and whistles to mine, but the basic idea is simple. I have a writeup on my site - link in my signature below.

 

[forestrymike]

no fossil. do you just have an indirect tank, no electric or gas heated DHW tank?

 

[BrownianHeatingTech]

no fossil. do you just have an indirect tank, no electric or gas heated DHW tank?

He's running an indirect in a rather interesting system. Click the second link in his signature to take a look

Joe

 

[Nofossil]

When I translated the hot water plumbing diagrams from my documnentation to my website, I made some serious errors. My apologies to anyone who actually tried to make sense of them....

I've updated them now. I'll start a new thread with a link and further apologies.

 

[Eric Johnson]

When the boiler is running, the sidearm will eventually fill the hot water heater with very hot water. As long as you can keep it from escaping back into the system, you'll get a day's worth of DHW in the tank after the boiler shuts down.

 

[Nofossil]

no fossil. do you just have an indirect tank, no electric or gas heated DHW tank?

Indirect. Since I have three heat sources (oil, wood, storage) the indirect tank can be heated by any of them. The storage is heated by wood, solar, and any residual oil boiler heat after the rare times that the oil turns on.