Storage not getting up to temp

[Rob186]

I have a vedrolux 37 with 1000 gal of pressurized storage and it is piped as a primary secondary lop system I can't get tanks up past 170 I'm burning 3-4 full loads of wood a day for a burn time of 6-8 hours the wood is dry it has been covered for 5-6 months and then goes in side 2 weeks before to finish drying I keep a fan blowing on the wood and a dehumidifier on all the time need to find out what the problem is soon getting sick loading this thing stack temp is 350 f pressure is at 11 psi

 

[flyingcow]

Not any help, but curious...has your wood been seasoned for over a year?

 

[flyingcow]

Do you have a big heatload?

 

[mikefrommaine]

Are your storage tanks insulated?
Is the boiler idleing at all?

 

[stee6043]

I'm curious about how long your wood has seasoned too but my first real question is what is the normal output temp of your boiler toward the end of a burn? Where are you measuring your "storage temp"?

If your boiler output is never above 170 your storage top temps will never be above 170. And if your storage bottom temps never exceed 140-150 +/- your boiler output probably wont exceed 170 if it's properly pulling from the bottom of the tank.

 

[Rob186]

The wood has been cut and split for 1 1/2 to 2 years the boiler isn't idling at all the house is 2700 square feet and my domestic hot water using a coil in the tanks I am pulling off the bottom of the tank and returning into the top then my zones supply off the top and return in the bottom that is boiler temp the bottom of the storage is 150 when boiler is at 170

 

[Rob186]

Today my wife lit the boiler at 9:00 am and it is still running at 7 pm and boiler temp is 150 with the bottom tank at 127

 

[woodsmaster]

Sounds like your losing heat somewhere. Do you have underground lines or is this in the house ? Is the house insulated decent ?

 

[BoilerMan]

What kind of return protection do you have? Can you read the return into the boiler and the output from the boiler. Am I understanding that the boiler supply will never go above 170 either? Is the boiler piped directly to the tank or is it the primary loop and the tank is just another take-off from the primary loop. Can you draw up a diagram of the piping. Is there a way to valve off all the loads and just let the boiler heat the tank?

TS

 

[Rob186]

Yea I can turn off the valves to the heating loops and it is piped the supply and return are piped into a loop with 2 tees close to each other and that loop goes into the tank the low return temp is controlled by delta t pumps the return and supply temp never get less than 20 degrees away from each other

 

[BoilerMan]

Indoor or outdoor setup?

TS

 

[stee6043]

The lack of periods makes my head hurt.

 

[Gasifier]

Anything new on your situation? I see your temps are not very cold in N.J. Just around freezing right now in Atlantic City. If the boiler is clean throughout and there is not much heat demand, is it possible your circulation pump is running too fast and the boiler does not have enough time to heat the water all the way to temp? What type of circulation pump? Does it have different speeds? How long have you had the boiler? Were you heating the storage before and bringing it up to temp without problem? I am curious what type of wood you are burning.

 

[maple1]

You definitely have something not right. That boiler should heat your house & your storage to 190 on a couple loads of wood no problem. I was just away from home for two days - when I got back yesterday around 4:00pm, the house (2700sq.ft. two storey) was at 14c and storage was at 140 top & 110 bottom. By 7pm the house was up to 20c and storage was 165 at top. 10pm storage was 180/170, threw another small load in & this morning I was still over 180 on top. My boiler has a lower output than yours. I'm not sure about adjustments on yours though.

We need more info. Plumbing diagrams, pictures, etc..

Is this a brand new setup?

One quick thing - two loads of wood will last me 8 hours (4 hours on a full firebox). Sounds like you're at half that - not sure what that means though. You should be getting way more heat out from all the wood it sounds like you're putting through it. Are you sure your wood is dry? Might be hard to tell for sure without a moisture meter on a fresh split surface - how much sizzling do you get? Right now I'm suspecting your wood - frequently filling with wet wood will dampen your fire.

 

[Nofossil]

I'll echo that something isn't right. We had some Eko owners with similar stories a few years back and it turned out that the secondary air was way off due to a manufacturing defect - easily remedied. Given how much wood you're burning, the heat has to be going somewhere, and we need a bit more information to help figure out where. Here are some possibilities:

1) Up the chimney as unburned hydrocarbons. I'd look for soot / creosote / visible smoke from chimney during the fire.
2) Up the chimney as hot flue gas - partially open damper, dirty internal HX, or some such. I'd look for high flue temps.
3) Lost to environment - poorly insulated buried lines or external storage tank. Need plumbing schematic and more complete system description.
4) Way higher than expected heat load - teenage girls taking long showers, open windows and doors, whatever.

In any event, more information would help. For readability's sake, here are a few extra periods ...........................

 

[Floydian]

Hi Rob,

I think another potential issue could be "bridging". Long periods of bridging would mean little to no gassification, lower flue temps, and lots of unburned hydrocarbons up the flue as Nofossil mentions.

I had my first little run in with bridging last night in my Vedolux 37 and two things that stood out to me were an 8-10% drop in efficiency from 81 lbs of wood(I am weighing wood and monitoring tanks temps, tank heat loss, btus to my infloor, etc.) and noticeably darker ash in my HX tubes. Up until this last firing all I have seen is a very light grey/brown colored ash.

Noah

 

[Clarkbug]

I have had the bridging issue that Noah mentions above, and it was mostly how I was loading my splits. I put them point down, and that was holding them up away from the nozzle. big bummer for me. Now I put the splits curved side down, and that has made a significant improvement.

What do you have the air settings at for the window and slidey-thing (tertiary air) on the door to the combustion tunnel?

A diagram of your system would definitely be helpful. From your description above, it sounds like you have a loop that goes to storage, but the house supply/return connect to that loop with closely spaced tees. Is there something that circulates that loop, other than the loading valve? If that is the piping arrangement you have, that could be part of the issue with not moving heat properly.

Also, you could give Dean a call, Im sure he would be willing to help get your system up and running!

 

[huffdawg]

Isolate your primary loop from your secondary loop. You should be able to force your boiler into idle mode. You should be able to get your boiler temps up to 195 to 200..

 

[Floydian]

Isolate your primary loop from your secondary loop. You should be able to force your boiler into idle mode. You should be able to get your boiler temps up to 195 to 200..

The Varm's wont idle. Something to due with idling not being allowed in Sweden I think. Shutdown is something like 200+ not sure, then the boiler has to be manually reset. So of course it MUST have storage.

Noah

 

[jebatty]

I pushed my storage to the very max today, 196F all the way, except for the very, very bottom, about the bottom 6", which was 175F. This wasn't exactly intentional, but the result of a small miscalculation on system draw during the burn and storage tank charging. I usually push storage to 190-193F. The extra 3-6F is equivalent to 5-10 lbs of wood.

 

[BoilerMan]

I pushed my storage to the very max today, 196F all the way, except for the very, very bottom, about the bottom 6", which was 175F. This wasn't exactly intentional, but the result of a small miscalculation on system draw during the burn and storage tank charging. I usually push storage to 190-193F. The extra 3-6F is equivalent to 5-10 lbs of wood.

Right on the ragged edge Jim! I love it, that's how we engineering types get. Start with 10% safety factor and soon we'll be pushing it to -10%...........LOL, just to get as close as we can and store as much energy in that tank as can fit, even if it's 5-10 pounds over.

TS

 

[stee6043]

I pushed my storage to the very max today, 196F all the way, except for the very, very bottom, about the bottom 6", which was 175F. This wasn't exactly intentional, but the result of a small miscalculation on system draw during the burn and storage tank charging. I usually push storage to 190-193F. The extra 3-6F is equivalent to 5-10 lbs of wood.

Wow....that is impressive. I think I'd have to try pretty hard to get it 196 top to bottom. Upper 180's is pretty typical but mid 190's is extra hard especially since I assume the Tarm is trying it's best to limit you to 195??? Nicely done...

 

[JP11]

Wow....that is impressive. I think I'd have to try pretty hard to get it 196 top to bottom. Upper 180's is pretty typical but mid 190's is extra hard especially since I assume the Tarm is trying it's best to limit you to 195??? Nicely done...

When I hit idle.. I'll get 196 top and 195 bottom temp.

LOT O BTUS stored in there.

 

[jebatty]

Upper 180's is pretty typical but mid 190's is extra hard especially since I assume the Tarm is trying it's best to limit you to 195???

It very likely was just short of the idle point, but I don't think it did idle because if it did, it wouldn't come out of idle until the boiler controller sensed about 180-185F, and the entire tank was above that, which means it never would have come out of idle and would not have shut down. I believe it coasted to this point as the last coals in the firebox burned out. As said, I didn't try to do this, and wouldn't. The target of 190-193F leaves a little "miscalculation" error factor to prevent an idle.

It sure was a surprise to see those temps. And probably a good thing, although a couple of days late. Temp this morning is -20F, "coldest day of the year," which isn't too remarkable given this is the first day of 2013! Happy New Year If us Minnesotans are lucky, we will see something in the -30 to -40F range before this winter is over. With luck like that, who needs to win the lottery?

 

[Gasifier]

Rob186. Have you had any luck bringing your storage temps up better?