Boiler to Boiler Plumbing?

boiler to boiler plumbing?

PostBy: stiffner On: Tue Nov 05, 2013 10:45 pm

I currently have a Harman sf160 boiler with two zones as my "winter heat". In the spring and fall I use a oil fired hot air furnace for primary heat. The oil furnace is 27yrs old and hot air heat stinks. I recently purchased a columbia oil fired boiler as a replacement for furnace. Which is better way to connect to coal boiler, in series or paralell? I have used this Harman for 7 yrs and have finally gotten everything dialed in and it is pretty efficient now. That being said I will only being using one or the other and don't want to change the way the coal boiler is running by adding another 25 gallons of water to heat. So can I simply tee into feed and return and add ball valves to isolate one or the other? Maybe a thread already covers this if someone can steer me there. thanks
Stove/Furnace Make: harman
Stove/Furnace Model: sf 160

Re: boiler to boiler plumbing?

PostBy: SMITTY On: Tue Nov 05, 2013 11:00 pm

I prefer parallel .. because it's both cheaper and easier (at least for me - I would've had the plumbing run in a big X in order to do series). With a circ running between the 2, you get the same effect anyway - no stratification of the water - same temp from top to bottom. Just my .02 ..

I just installed mine last week this way with lots of help from Rob R. and others, BUT I take full responsibility for my twist on the ideas to make it work. As you;ll see, my chimney connector pipe is below LESS than ideal ...

You might want to fast-forward thru the first 4 pages of my meltdown though to get to the actual install ... :lol: Jim D.'s stoker boiler install thread
Stoker Coal Boiler: Patriot Coal - (custom built by Jim Dorsey, Taunton MA - RIP 4/18/13)
Hand Fed Coal Stove: Harman Mark III (SOLD!)
Coal Size/Type: Rice / Blaschak anthracite
Other Heating: Oil fired Burnham boiler

Re: boiler to boiler plumbing?

PostBy: Rick 386 On: Wed Nov 06, 2013 11:12 pm


That is the way we have our AA 260 plumbed in right now. I open valves for coal and shut off valves to isolate the oil boiler. We had a new EFM oil boiler installed about 6-7 years ago. I forget exactly when. We ran the oil boiler the first summer it was hooked up. That fall when I switched over to coal, I never looked back. It's been coal all the year since then.

However a primary secondary setup would be making things easier. You just select the heat input device to warm the water and the controls don't know which one is supplying the heated fluid.

Rick 386
Stoker Coal Boiler: AA 260 heating both sides of twin farmhouse
Hot Air Coal Stoker Stove: LL Hyfire II w/ coaltrol in garage
Coal Size/Type: Pea in AA 260, Rice in LL Hyfire II
Other Heating: Gas fired infared at work

Re: boiler to boiler plumbing?

PostBy: engineer On: Thu Nov 07, 2013 5:20 am

Most operator manuals will show a parallel hookup. I have installed and run a series operation with a New Yorker model WC plumbed myself in series and also run a New Yorker model WC plumbed by plumber for new house in parallel. Both configerations will work. For my money a series installation with appropriate controls/isolation works a bit better in that it will always keep oil boiler warm and not running. Parallel operation will have the oil run more often unless the oil boiler is actually shut off defeating the backup feature.
Stove/Furnace Make: hoval
Stove/Furnace Model: duolyte 30