Wood boiler power outage protection

my solution was fairly cheap, 12V school bus circ. pump, battery maintainer, and group 31 batteries, relay to turn the 12V current on when the power drops out, the circ. is in series with my main load circ. to use my house as the dump zone, and it keeps the combine or whatever I rob batteries out of for the winter charged and going.

I had a ton of fin tube I was going to use, but did not want the clutter, and did not see a good way to keep the fin tubes from holding ash/crap that seems to slowly accumulate on every flat surface in the boiler shed. plus I had everything laying around that I needed besides for the pump, and that was cheap enough at the local truck boneyard.

poor people have poor ways I guess

Overheat loop still needed for pump failures or plugged Y strainer. I once had to clean strainer with a loaded boiler idling. It was first startup after some mods and too much pipe dope.

I often wonder if the batter/inverter setup money would be better spent on one of the newer inverter generators
that have electric start.

rkusek said:

Overheat loop still needed for pump failures or plugged Y strainer. I once had to clean strainer with a loaded boiler idling. It was first startup after some mods and too much pipe dope.

I often wonder if the batter/inverter setup money would be better spent on one of the newer inverter generators
that have electric start.

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Great if you are home to get it running.

I mean the ones that now have electric start. Granted, I don't think they are turn key for this yet. A small auto transfer type switch would be needed. It would be a smaller version of the 3-5 grand whole home versions.

In Vermont, Green Mountain Power is offering a Tesla Power Wall for $1500.00.

rkusek said:

I mean the ones that now have electric start. Granted, I don't think they are turn key for this yet. A small auto transfer type switch would be needed. It would be a smaller version of the 3-5 grand whole home versions.

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I have a 14KW generator now with auto transfer and was advised not to rely on it for protection. I took that advice and installed the NO zone valve and 32 feet of 3/4 baseboard directly above the boiler per the plans.

Redundancy

Redundancy

Redundancy

If it hasn't been suggested yet(I skipped to the end) think about a thermo syphon type of system. Old farm tractors used it before they decided to put water pumps on. Basically, you had the engine which created heat(obviously) and a connection at the top out the front of the head that led to the top of the radiator. At the bottom of the radiator, another connection which led to the bottom of the block. The heat in the block created a natural circulation. In that situation you had a fan, but I would think the coldness in winter would be enough. I would suggest a really large radiator such as one out of a HD pickup truck or larger.
A generator to keep things running would obviously be better.

I have seen the fin tube installed with a bit of slope also, to aid thermosiphon.

Use a large diameter fin tube or two 3/4" in parallel to keep that pressure drop as low as possible to encourage thermosiphon.

The old gravity powered hydronic systems used large diameter piping to assure that flow movement.

Bob Rohr said:

I have seen the fin tube installed with a bit of slope also, to aid thermosiphon.

Use a large diameter fin tube or two 3/4" in parallel to keep that pressure drop as low as possible to encourage thermosiphon.

The old gravity powered hydronic systems used large diameter piping to assure that flow movement.

Click to expand...

I thought of having a slope on mine feeding one end and returning at the other and was told not to bother I did however feed (and return) the dump zone in the middle of the run as well as add an air eliminator off a cross tee. I've tested it several times by shutting off the power to the boiler and it works very fast.

I have 40' of fin tube all pitched properly with a normally open automag valve. It must be ok, John Siegenthaler used a photo of it in one of his presentations.

@goosegunner, that is a thing of beauty.

I'm about to install my dump zone and have a questing for you guys.

What side of the zone should the hot water enter, low side or high side of the zone?

My thinking was the high side. Anyone want to correct me?
@Bob Rohr ?

@Bad LP, what was the thought behind not needing to pitch the dump zone?

Mine enters on the high side or left and is pitch to the right. The pipe on the wall below the dump zone is also pitched going back to the return.

I was told not to bother in that the hot water coming out of the top of the boiler was going to push to the return side no matter what. I did put some slight pitch on the supply and return lines leading from the boiler verticals to the fin tube but it's a horizontal run under 2 feet away. Fin tube is dead level.

It's amazing how fast the hot water pushes out the cold water into the return.

Thanks, that's what I was thinking. The initial push from the density difference is the driving factor. I'll still add an inch or so of pitch over 7'. I realized thats about all the room I have anyways after I started to plumb it.

The automag valve looks restrictive to me, doesn't appear to open very far. Maybe I'll share a picture.