Here’s my first post after much reading on this very helpful site…

I just solved one of my fossil fuel crisis’ with the purchase of a sweet 1980 Chevy Chevette.  36k original miles, one owner, no winter driving ever, 4 on the floor, marketed at 43 MPG when new...I’m up to 30 so far with some tune-up work pending.  This solves the problem with my vehicle fuel consumption...now I need to solve the problem with my heating system!

I’ve answered a lot of questions already from other posts but would like to confirm a few things and ask some more questions.  Thanks in advance for your help and patience as I try and figure all this out!  If you need help with your Chevette, just let me know!

I would like to install an Add-On Wood Boiler to my existing Oil-Fired, FHW System.  The existing unit is in the basement and exhausts into 1 of 2 flus in my tile lined, brick chimney.  The other flu supports a nice 1980 Garrison wood stove located in our first floor living room.  I have located a slightly used Thermo-Control 500, Boiler Model for a price I can afford but don’t think I can use it without additional expense for a new chimney or giving up the woodstove in the living room which we don’t really want to do.  Here are my questions.

Is there any way to use one of the existing flus for the boiler with the other appliance?

Is my chimney type even adequate to use with the wood boiler? (assuming it’s (chimney) in good shape, of course)

If I need a new chimney to gain a flu, is there a type I could somehow run out of my basement and up the side of the house?  If so, about how much would that cost?

Is it clearly advantageous to have a water storage system or is that just a nice to have?

It seems like without the water storage, the wood fuel energy would be wasted unless the baseboard loop was calling for heat...I think this is the purpose of water storage...keep heating the water even if the baseboard loop isn’t circulatimg...is this right?

OK...that’s enough to get em going. - Check out the Vette!

Hope someone will want to help out!

Some of my best adolescent memories happened in a 1980 Chevette!

You need a dedicated flue for your wood burner, I am not sure if it needs to be lined with stainless steel or not.  You can power vent your oil boiler, total price would be determined by height of your house.  I would figure in about a grand.

You are correct about the water storage.  However, a lot of people add the storage later with their savings from the previous year.

Nice find on the Chevette!

Water storage is not as important with a conventional boiler like that - a 4-way mixing valve can also be installed which will help even out the heat delivery to the house - this is something I suggest with most wood boilers (or hydronic systems in general).

http://www.hearth.com/econtent/index.php/wiki/4_Way_Mixing_Valve/

Certainly you can run a new chimney up the side of the house- that is HT chimney, metal chimney.

The materials are pretty expensive- if you are DIY you might get by with $1200-1500 for an out and up.

Brands include Selkirk, Metal-fab, Airjet, Hart and Cooley, Excel and many more. Check your local stove shop, plumbing supply or even big box home store.

If the Garrison chimney comes all the way down and you can get rid of that stove, you might be able to use it for the TC. It probably does need a new SS liner dropped down for additional safety.

Thanks Sinnian!

I’ve owned the car 3 weeks...in that short time I’ve decided that that EVERYONE in America who was old enough to remember them has (had) a previous relationship with...or in a Chevette! Enjoy those memories!  (by the way...I found the car in Wiscasset!)

I figured I needed a dedicated flue.  Can someone else help me with the “is what I have for a chimney adequate for use with a wood boiler?”

OK so the idea of power venting the oil boiler is so I can use that flue for the wood boiler?...assuming the flue is adequate, of course - right?

Do power vent pipes need to go to the height of the existing chimney?...I though they just stubbed out of the wall.  I’m trying to figure out why the cost relates to the height of the house.

It seems silly not to have some water storage...are there requirements for what you can use for a tank?  Whattabout those food grade juice totes or something similar?  Probably not good with hot water… I read someone else was using 275 gallon oil tanks...would 1 of those be good or if I’m gonna do it, should I just do 2-3?

Thanks again---anyone else got advice for me?

I’d put the storage on the back burner for starters - very few people have it with conventional boilers....just with the gasifiers, since they are designed to burn hot and fast.

Also, it is important to take into account the existing system - water capacity of the other boiler as well as the piping and radiation. I think you have to solve the chimney situation first.

Pressurized storage needs to have an ASME approved or equiv pressure vessel. I would never suggest that folks go rigging up various tanks not designed for high pressure - but if you want to read more dig around the forum....some posts on non-pressurized storage, etc. are around.

Webmaster - 29 June 2008 09:39 PM

I’d put the storage on the back burner for starters - very few people have it with conventional boilers....just with the gasifiers, since they are designed to burn hot and fast.

Also, it is important to take into account the existing system - water capacity of the other boiler as well as the piping and radiation. I think you have to solve the chimney situation first.

Pressurized storage needs to have an ASME approved or equiv pressure vessel. I would never suggest that folks go rigging up various tanks not designed for high pressure - but if you want to read more dig around the forum....some posts on non-pressurized storage, etc. are around.

i would think that any boiler type,gasifier or not, would benefit from storage. they all run more effeciently at full bore dont they?

Check out the Vette!

Hope you keep the Chev in the garage come wintuh. Maine roads would love to chomp on that one. There are various clearance issues with side ( power ) venting. Mostly related to fumes being exhausted into windows or vents above. I would have a local certified sweep check out your existing chimneys and get a price to line one for your new boiler.

All that sounds very logical, practical, and like good advice Craig...thanks a lot!

I read the mixing valve story and that clarifies things there too, sounds like a no brainer.

Guess I was missing the “under pressure” thing...no need for the storage with the valve anyway.

I am a professional DIY’er...I’m thinking a new chimney is the way to go...the placement of my current boiler at the base of the existing chimney is on an elevated slab due to ledge under our house.  This means low clearance to the ceiling, up and down all the time for filling etc.  A new chimney on the opposite side of the basement with full height ceiling and plumbing back to the oil boiler to tie in sounds like a better idea...would you agree?  Clearance from the top of the wood boiler to the bottom of the ceiling on top of the elevated slab would only be about 3.5-4 feet...that’s probably too little anyway...?

Here’s my big question...my foundation is very low in the ground so I’ve only got about 1 foot above grade before I get to my siding...how the heck would I run a HT (assume this means high temperature?) chimney out in that scenario?  Could I dig out a hole similar to a window well and then blow through the concrete there?  Do these chimneys go right through the rim/band joists and siding or concrete?

I’ll say this...this is a very challenging project...harder than the Chevette by a longshot!

Willman...I’ve got bad news...that poor Shove-ette is doomed. 

That gray, solid substance in the form of a rectangle behind her car IS my garage and won’t be protecting anything just yet...too many projects.  In addition, the overly complex spreadsheet I used to justify the purchase in the first place says I’ll need to drive it in the winter or the payback will come too late.  I’m going to look into another undercoat before snow but don’t know if they even do that anymore.  I’ve got very mixed feelings about driving it in the salt as I come from an antique Ford family and to drive a car like that in the salt is a horrible sin...even if it is a Chevy!  (if it was a Pinto...I probably couldn’t do it!)

So I may have to vent it higher than the lowest window...which on that end of the house is 1st story only...I’d better get a pro sweep down here.  Is a good sweep qualified to answer every single question I might have about what I’m trying to do here?

Thanks - Bill

Yeah, I think the best way would be to dig out a well and line it with PT wood or something like that to hold the dirt back.....you might have to do some rigging to stop snow from filling the thing.

All things being equal, it would be nice to locate it near your existing boiler.....but the 3.5 feet above it is probably fine anyway.

Storage is always good....but again it depends on a lot of things. Do you know the water capacity of the thermo-control?

I’d have to rig something up...I’d probably just use rock with a stone floor for the chimney hole.  What is the advantage of locating it near the existing boiler...I’d be about 30 feet away with a new chimney.

I can’t find the water capacity of the thing but it’s not much...it’s just the coils on 2 walls and ceiling of the thing.  Their website tells me the coils equate to 11.5-feet of heating surface area...if that tells you anything.

It’s cool you guys are so active/responsive on a site about heat in the off-season - thanks!

OK, time for me to be honest.....I don’t like those boilers with the coils like that! The same company now makes fully water jacketed models. There are a lot of down-sides to such a boiler....including easier overheat, bad heat transfer, etc.

Personally, I would keep looking.........

Advantages of locating near the existing are mostly less plumbing - copper is expensive these days. Also less heat loss from the piping, but that can be fixed by insulation. There are some various diagrams around on the ways to plumb these things - you can often download another brands manual...or the ones from the TC web site.

But, again, I would keep looking. If you are going to use older technology, I would suggest a higher water volume unit with wet legs, etc...which means water around most or all sides of the boiler vessel.

Craig - Thanks for being honest...it’s a lost art!  I hear what you’re saying…

Chances are good someone else is going to buy the thing before I’m ready to pull the trigger anyway based on all the leg work I need to do to figure it out - I’m not the type to “buy now and figure out later”.  I was looking at units on the net for 4-5 grand last week then I saw this one and had to check it out...I love a good deal but at the same time, like to do it as right as I can afford.  I’ll keep working on the project and see where it takes me.

If you were going to spend no more than 5k and knowing my situation...what would you do?  I’ve got a terrific chance to pay something off in record time but I need to pull the trigger soon...like before winter or I’ll miss it. 

Similar to the Chevette purchase, I don’t want to look back 2, 3, 4 years from now and say..."I should-a pulled the trigger on a wood boiler in 2008!”

hey Bill I saw this on craigs list, check it out. Craig is the resident expert on all things Tarm.
http://maine.craigslist.org/for/707694867.html
Will

That boiler is owned by a friend of mine. It is an orange Solo but it is the short one with the small firebox, which makes me think it was primarily intended for coal. I can get more info if anyone is interested.

A reminder for all open system boilers, especially open storage with a steel tank. Don’t forget to treat the water for pH balance and O2 scavenger. Both spell rust big time if out of range.