Wood boiler not keeping up with demand

[buck0123]

My wood boiler has a 9 gallon water jacket hooked up to my oil boiler for back up. The problem is when the house calls for heat the water temp drops to about 130-140 and will not rise.

This is the way I hooked it up. mine is all one zone and after the circulator pump on the oil boiler is a flow control valve.


my house is around 3000 sq feet.

the outside temp was around 55-60 degrees.

Anyone have any ideas how to solve this problem?

Thanks
Bill

 

[__dan]

Hey Bill. The longtime posters who responded to your other thread probably saw something that they themselves tried and fought with for a long time. Then they swapped out to a gasification boiler and would never go back.

Basically, without a gasification second stage burner, half of the fuel and half of the btus are going up the stack as smoke. So you can heat your house with such a unit if you are prepared to move 8 - 10 cord annually through it. Roughly doubling overall system efficiency by going to a modern gasification boiler with storage, the fuel appetite could go down by half to 4 - 5 cord.

That's why you saw the guys responding in your other thread with 'good luck but plan for a gasser'. That's pretty much what I saw in the other thread. It was obvious to the longtimers who had already tried that. Second stage combustion temp needs to get up over 1200 deg F to burn the remaining fuel components in the smoke. You have to look at the unit you have to see if it has that capacity to run in that manner. Single stage burners with the water jacket surrounding the fire just do not burn hot enough to burn all of the fuel that is contained in the cord wood fuel.

 

[buck0123]

If I turn down the thermostat I don't take long for the water temp go get back up to 185. What I was thinking is that my heated water loop is smaller than the heating loop that heats the house I thought if I had water storage it would make my heated water loop bigger than the house loop that way it would not empty the hot water so fast. All of the outdoor wood boilers have a couple hundred gallons of water. You don't think more water storage would help?

Thanks
Bill

 

[PassionForFire&Water]

If I turn down the thermostat I don't take long for the water temp go get back up to 185. What I was thinking is that my heated water loop is smaller than the heating loop that heats the house I thought if I had water storage it would make my heated water loop bigger than the house loop that way it would not empty the hot water so fast. All of the outdoor wood boilers have a couple hundred gallons of water. You don't think more water storage would help?

Thanks
Bill

Research: boiler loading valve, LK820 or LK810

You need a device that allows the boiler water to come up to temperature gradually, rather then being quenched all the time with to much cold water returning to the boiler.

 

[BoiledOver]

Hey Bill:

Sounds like you jumped right in. I did the same with an inefficient set-up that I thought would work. After biting the bullet and throwing the money out there, I am running a gasser and very pleased. The total investment, (actually just $7,000 total including the logs purchased), will be at the break even point of propane after its 5th winter.

With that said, hot water heating systems operate under strict rules. The rules are known to man already but it is a lot to learn. Have you done a heat loss analysis? Did you figure the head of your piping to correctly size your circulators? Do you know the output of the stove you are using? And many more questions need to be answered before designing the proper system.

Right off the top is a question about head on the wood boiler loop. If the head is low and you are using the 1542 circulator, it is pushing way too much water through and over cooling the stove. Water circulating through a wood fired boiler will cause problems if below 140F.

It appears you may need to take some time over the summer months to become educated to the principles involved in heating with a wood fired boiler. After that maybe you can make what you have work or decide that some other appliance is in order. There is just about everything you will ever need to study right here on this sight. All it takes is time to sift through the threads.

Hope ya get a handle on it.

 

[buck0123]

I am using taco. 007 circulator pump from lowes

 

[maple1]

Fundamentals: how dry is your wood, what is your chimney draft, and what are your stack temps?

If the boiler can't keep the water you have up to temp, adding more will not help.