boiler piping

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

mikes67

Member
Sep 1, 2009
32
SE PA
Hi everyone,
First let me say I have been following this forum for six months now, and have gotten tons of useful info from it.
This summer I purchased an EB 150 after reading many many reviews of all sorts of boilers on here.
After getting it down the basement which was a project in itself I am ready to start the piping I am quickly realizing that i need some guidance on this. Heres what I wasnt to do. Can someone direct me to some diagrams. I have looked on here at a lot of info on this topic but its a bit overwhelming.

I have an existing gas boiler I want to use as a back up. I want the gas boiler to switch on automaticly if the EB 150 burns out. I would like to put in storage but the budget doesnt allow this year. The house uses 12 cast iron radiators for heat transfer.
Im sure this is not enough info but im trying to learn so please bear with me.
 
Congrats.
I suggest piping the supplies and returns together (t'd). Set your gas boiler to come on at 140 or less, the Econoburn control starts the primary pump @ 150. This way if the fire goes out the wood circ. stops @ 150 & the gas takes over below 140. When no zones are calling & wood is up to temp. flow through the gas boiler will actually be in reverse, this is not a problem & will give the zones the hottest water when they call. It will also maintain temp. of the gas boiler which will satisfy your tankless domestic coil if you have one. Good luck.
 
mikes67 said:
Hi everyone,
First let me say I have been following this forum for six months now, and have gotten tons of useful info from it.
This summer I purchased an EB 150 after reading many many reviews of all sorts of boilers on here.
After getting it down the basement which was a project in itself I am ready to start the piping I am quickly realizing that i need some guidance on this. Heres what I wasnt to do. Can someone direct me to some diagrams. I have looked on here at a lot of info on this topic but its a bit overwhelming.

I have an existing gas boiler I want to use as a back up. I want the gas boiler to switch on automaticly if the EB 150 burns out. I would like to put in storage but the budget doesnt allow this year. The house uses 12 cast iron radiators for heat transfer.
Im sure this is not enough info but im trying to learn so please bear with me.

There are three fundamental approaches that I can think of for plumbing two boilers. There are nearly an infinite number of variations, and the comments below don't necessarily apply to all variations:

1) In series - all the water goes through both boilers. This is the simplest and may be desirable if you have a hot water coil in your gas boiler. This is also the least efficient and lowest performance, since you always have to heat both boilers.

2) In parallel (supply / return) - there is a hot water (supply) line and a cold water (return) line. The output of both boilers is connected to the supply, and the inlet of both boilers is connected to the return. This is a reasonably simple and efficient approach. It requires check valves (usually in the circulators) so that you don't get reverse flow through the inactive boiler.

3) Primary / Secondary - there is a loop that connects all heat sources and all heat loads. Each source and load draws water from the loop and returns water to the loop. This provides ultimate control of flow at all points and scales well to large and complex systems. It consumes more electricity and may involve more complicated plumbing.

Both the primary / secondary and parallel approaches are well documented in stickies at the top of this forum page. In both cases, just ignore storage if you're not planning it at the moment.
 
Congratulations--

I second the comments above, with one possible exception regarding storage, as follows:

Consider designing and plumbing your system so that there will be an existing spot intended to "tie in" storage later. You may not add it for a while, but having the provision will not only make it easier when you do- it may avoid having to pull-apart and re-do and end up spending extra time, materials, etc.

When I first plumbed my system last winter, I put in a pair of ball valves with pipe unions where storage was intended to tie in. Now that I am back to work on my storage, I was able to "pick up right there" without even needing to drain the boiler and existing plumbing.
 
Mike67:

I was where you are 3 years ago when I installed my LDJ boiler. After a bunch of research, I paralleled my boilers. After a season of heating that way I ended up taking the leap and removing my oil boiler all together. When I did that, I also re-piped to a primary/secondary system with a pumping away module.

I highly recommend these books by Dan Holohan:

http://www.heatinghelp.com/products/Super-Deals/14/131/Go-With-The-Flow

They really explained the principles well and allowed me to design a piping arrangement that is now so efficient my boiler almost never goes off idle fire and runs on the boiler's minimum temperature. I am not a plumber, just a clueless homeowner, and they were well worth the $80. Good Luck!
 
Don't sell yourself short here ODH! Your a home owner that knows how to follow lucid advice. :)
 
The duck strikes again %-P
 
Status
Not open for further replies.