Will it work

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It's hard to answer without some info about your piping.
I'm assuming by monoflo system you mean a one pipe loop with monoflo tees to each radiator? To circulate by gravity I would guess it would have to be designed to do that from the beginning with big piping and minimal restrictions.
A pump is not a big expense. I'd pump it if it was me.
 
When I say gravity fed boiler I don't mean hopper fed but a hand fired boiler without pumps
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Gravity hot water is the simplest way to heat home or building up to three stories tall from the basement. its something that cannot be done with baseboard heating loops.
You have not said whether you have cast iron or steel radiators. You need them to make gravity hot water system work.
 
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Upon further review I do not have a monoflo system. I have a 2 pipe direct return mixed with a 2 pipe reverse return. Boiler is in basement. The supply and return manifold looks like 2 inch black iron pipe. I only have 2 cast iron rads and there on a branch that does the rear on the first floor with copper baseboard heating 2 rooms and each of the cast rads heating a bathroom and pantry. All other branches from the supply support a series of copper fin baseboard before connecting to the return line. Each branch from supply only heats 2 rooms except for that 1st one I mentioned. It is a 2 story house.
 
Was a pump used up to this point? I'm trying to gather the history of how it's been working.
 
Yes a circulator pump is on the system now withat a oil boiler. Im basically just wondering if it will work because Im putting a coal wood boiler onto the system and the boiler I'm looking at runs without electricity but ill hAve a pump installed for the coal boiler to. So my thing is I'm wondering if I build a rocking coal/wood fire then leave for work and the power goes out which it tends to do couple times a winter I'm wondering if the water jackets in the boiler would get so hot that it would damage the stove. This boiler has a mechanical run damper so it will continue to roar even with the power being out.
 
Makes sense. My guess is that if the system wasn't designed to gravity flow it won't very well. Normally with a circ you are trying not to gravity flow.
But there are a lot of guys on here who have more experience than me.
 
The boiler shouldn't continue to roar when the power goes out. The damper should close.

I have my two second floor baseboard zones plumbed thru a normally open zone valve so it will dump heat in a power outage. If power gets cut to the zone valve, it defaults to open, then the zones convect naturally. You need to keep the path to your dump zones as straight up as possible off the top of the boiler. Oversizing that circuit would help some too. But you should not rely on just that to avoid an overheat - as mentioned, the boiler should have its air cut off when the power goes out. That's 2 things to help. I assume you will still use a circulator? Another thing you could do is use a circ that doesn't draw much power (e.g. Grundfos Alpha) and power it through a UPS. I have a 2200va UPS I use with my loading unit that I plug into when I am going out, or the weather is bad, while burning. That's 3 things to help - redundancy is a very good thing when it comes to overheat protection.
 
I visited DS Machine's shop 8-10 years ago. Very nice people. Seemed like quality boilers. I bet they could give some answers.
 
Hey Bung, i responded to your other post. sorry for delay, i ski like a fool in the winter. My system works really good on gravity, but i have some pretty large pipes.The manual damper on the 3200 works like charm, but i would be concerned about a dump zone. call me or send message. Luke