Harmon SF-260 in Tandem With Peerless Oil

I am going to be Installing a Harman sf-260 in tandem with peerless oil furnace. I was told by the dealer I need to find a place to "dump" Heat because unlike a oil furnace it stays burning. But I can not find a diagram or how to install a system like this. Harman gives you simple instructions. I Would like detaled drawings of how to plumb this in and, also where do I wire the second circulator pump? If any one has a stup like this can you send me some Pics so I can work off of them.

Thanks,
Nick

I just went to Harman's page the Harman sf-260 is a nice looking setup. I guess you want to use it to heat the water inside your boiler. It shouldn't be too difficult to plumb. I'm not an expertt although I worked with my dad as a plumber for a few years. I think you simply run one line from the coal applicancer into the RV on your oil burner and then another line from the coal appliance to the drain on your oil furnace. On one of the runs you would install a circulator, and shutoffs. I wouldn't use check valves because the springs int hem become corroded easily. Anyway, if your not omfortable hire a plumber they shouldn't charge but a few hundred. Good luck.

Thanks, I was hoping someone here has a coal boiler piped in with there forced hot water oil boiler,so they can tell me how they did it and post some pics.
Please someone help me!

Each boiler is plumbed different, Can you take a photo of your oil boiler showing the plumbing inlet and outlet, circulator pump and zone valves ?? This way we can make recommendations on your instalation instead of trying to interpret someone elses system to your settup.

For example, my boiler is outside in a separate building, about halfway between my shop and the house, I use the boiler to heat both the shop and house, I use burried pipes and water/water heat exchangers to transfer the heat from the boiler water to the shop and house systems, the water doesn't mix.

For a generic answer, I would find the plumbing that is returning the cool water from your baseboards or radiators, and before this water gets to the oil boiler plumb the water to the inlet of your coal boiler. Then from the outlet of the coal boiler, plumb the coal heated water into the oil boiler inlet. install shut off valves and a connecting valve between the two pipes running from the water return to and from the coal stove.

Give us a photo or two and we can make specific suggestions.

Hope this helps. Greg L

.

Thanks Greg,
I will take some pics.

The attached pdf is a schematic of the general plumbing required. Depending on the open or close settings of valves A, B, C & D you can have your coal boiler in series with your existing boiler or isolated from it. The schematic also shows the piping need to "power purge" the air out of a new installation. There can be any number of zones which can be heat zones or indirect hot water heaters. There are many other details to consider which might include an additional pump in a primary/secondary type plumbing loop. Useful when the boilers are located in an outbuilding or in very large home installations.

here is my boiler

Hi Extreem, this will be pretty easy. Under your circulator pump, there is a length of black pipe. You need to remove it, and install a short nipple, a tee, short nipple, ball valve, short nipple,tee, and short nipple. Make the combination the same length as the piece of pipe removed. At each tee install a ball valve.

From the first tee under the pump connect this [after the ball valve] to the inlet of the coal boiler. Connect the outlet of the coal boiler to the lower tee.

When using the coal boiler, close the ball valve between the tee's and open the other two ball valves. The return water comes through the pump, is pushed to the coal boiler, heated , returned to the oil boiler and sent on to the house using the exsisting valves, thermostats and plumbing.

You need to set the target temperature in the oil boiler lower than the target temperature in the coal boiler. This way the coal boiler will provide the heat to the house, and the oil boiler will run only if the coal can't produce enough heat, or you stopped at the pub on the way home from work, and the boiler runs low on coal.

You can install the tees and valves above the pump if you wish, then the pump will pull the water through the coal boiler.

Hope this helps and makes sense. Greg L

I am attempting the same set up with the same two furnaces. my Harman dealer told me that my coal furnace could heat my domestic hot water, using the domestic coil in my peerless boiler - my plumber said he wanted to install a domestic hot water coil in my Harman - then feed the domestic coil in my peerless... I'm a little confused.. - I looked at the schematic that yanche posted and it was what I had in mind... I trust my furnace guy but I don't think he has worked on too many Harman stoves. any help is appreciated... Nothing is hooked up yet.. Also - how much oil do you use in the summer to heat your water? I was guessing 300 gal - family of 4.... Am I far off???? I have 4 zones in the house 2400 sq ft. I burn 1000 gal/yr Hoping to cut that as much as possible.... Also thinking of using nut coal - it says it will burn pea or better... any recomendations..
thanks in advance....

Just a stupid question. i'm going to put in a coal boiler next year, if I can get one. Why would you put two expansion tanks an feed w ater pressure regulators in. Wouldn't one be enough?

Either one much larger expansion tank or two smaller tanks.. the amount of expansion capacity needed is dependant on the amount of water in the heating system.. So when you add a second boiler you greatly increase the water in the sytem and you need to increase the expansion tank capacity as well.

Greg L

.

Yanche wrote:The attached pdf is a schematic of the general plumbing required. Depending on the open or close settings of valves A, B, C & D you can have your coal boiler in series with your existing boiler or isolated from it. The schematic also shows the piping need to "power purge" the air out of a new installation. There can be any number of zones which can be heat zones or indirect hot water heaters. There are many other details to consider which might include an additional pump in a primary/secondary type plumbing loop. Useful when the boilers are located in an outbuilding or in very large home installations.

Would this design keep the oil boiler too cool for the DHW coil ? Would the oil boiler fire more even with the aquastat temps way down? This will be easier for me rather than cutting in to my return. Any feed back will be helpful Thanks Ed

When the valves are set so that both boilers are in series the non-coal boiler is normally disabled from firing. The boiler water temperature is controlled by the coal boiler's aquastat. So if there is no demand for heat, and hence no water flow, the non-coal boiler's water temperature will drop, perhaps below that acceptable for the domestic hot water coil. How much it drops will depend on the heat loss of the non-coal boiler and the frequency of heat demand by the zone thermostats.

As you suggest the non-coal boiler could be fired to raise only it's boiler water temperature. It would be a difficult analysis to predict how often that would be needed. It would be less than the summertime use to heat domestic hot water only. In my installation I have a indirect hot water heater so your concern doesn't apply.

In effect what you are doing is using the non-coal boiler as a tank for heating hot water. I guess you could come up with a piping and control method that would treat the non-coal boiler like a zone. This way when ever it's water temperature falls that zone would come on, re-heating it with coal heated boiler water. I have to think more on it.

If I sent my return water from my 3 zone (Pumps) system to the coal boiler first then back to the oil boiler return, then add add a pump (extra zone)from the supply manifold to the return on the oil boiler and control it with strap on aquastat mounted to the supply pipe on the oil boiler to maintain a min boiler temp for my dhw coil. I do understand about heat loss up the pipe on the oil boiler with this set up. I know auto stack dampers are not legal on oil units. There has to be safe way to run a stack damper on a oil unit. I have had a couple delayed starts on my oil boiler and smelled them right away. I would think if the auto damper did malfunction the famly would run from the house from the smell before the co killed us.