If You Had to...

I have an oil burner/forced water heating a home of 4200 square feet via 4 zones. The first floor is radiant floor heat and the second is baseboard.

The current boiler is failing (it has lived a useful life). It provides our year round hot water by pumping into an 80 gallon electric ( turned off) hot water tank.

So the basic need is to heat the above described square footage in our two story home and provide our hot water needs.

We are agreeable to an outdoor of the home unit versus located in the basement as it is now, if need be.

We would prefer a dual unit (oil/coal) but this is not a deal breaker. But it would make life easier for summer hot water needs and for leaving the home unattended in the winter if need be.

If you had to make a purchase today to handle the above situation what would you? Meaning what make and model boiler would you seek? And why.....

As usual, thank you ahead of time.

You would be hard pressed to find a " bad stoker boiler" today. Assuming a healthy chimney, there is really no need
to go to an outside unit. The duel fuel option pretty much limits your options. Keystoker is the one to run with. Beefy
and simple, it is the one I would buy, assuming you can get one!

More answers about your home. Insulation? Windows? Doors? Basement? Walkout? Garage? Chimney situation? What is the Gross BTU is your old boiler? Do you need a brand new stoker, or will a quality rebuilt on do the job? Are you in Coal country or somewhere where it is readily available?

An answer: A coal stoker boiler. AA, AHS, EFM, Keystoker, Harman. BTU loading? If 130 K is enough, you are in luck with the base models of each company. EFM 520's are realistically good up to about 180K of continuous loading, so that is the largest output of the above listed models. The EFM can easily be regulated from 50K to 186K using air and fuel setting. No need to install or replace anything on the machine. They are very adaptable.
I can strongly suggest that you might not want to add an oil option to your coal stoker. It will work, but not as efficiently as an oil boiler. Having said that, AA. AHS do not make a dual fuel, only EFM, Keystoker, and Harman do. Looking forward to your answers and comments....
:pepsi: :discuss: :bsod:

Thanks everyone thus far...some answers to the questions asked....

Southern NH, good insulation and windows and doors, home built in 77 and addition in 84...bulkhead and stair access to basement, not a walkout. good chimney. Current BTU's on the old boiler 178,000 Peerless Boiler

In general I would not recommend a dual fuel unit. I would suggest:

1. Stoker boiler properly sized or slightly undersized.

2. Second non coal fuel boiler, for backup and/or makeup on the coldest of days.

3. Indirect hot water heater.

There are a lot of good coal stoker type boiler manufactures. Consider refurbished units. Most important is coal storage and ash removal considerations. Above all get the "system design" right first.

Keystoker and EFM both make a "dual" fuel, the oil can be used as the primary however it is essentially a add on and really meant for emergency or temporary use. I believe on both uses it comes with a cover so there is a little bit of work involved to switch between the two fuels. From my understanding they are not nearly as efficient when using oil. It is a nice convenience. If you're going to get a coal boiler you should be ready to commit to using the coal in it even with the optional oil burner unless of course oil drops to some ridiculously low price which is not going to happen.

If I was you I'd be looking at either an EFM, AHS, or Axemane Anderson with an auger. They all make units capable of providing what you need.

Al F wrote:But it would make life easier for summer hot water needs and for leaving the home unattended in the winter if need be.

Actually you can run the coal year round, the larger boilers are insulated or so efficient they do not put too much excessive heat into the basement. Actually recommended especially if you are in an area close to the coal source, it might actually be cheaper. By running it year round you will cut down on maintenance (sounds weird but that is the way it is) and you'll extend the life of the unit greatly. We go through about 1 ton in 3 to 4 months. You'll have to take care of it about once a week during this period...

I should have added that windows were upgraded in the mid 90's.

No problem being committed to the coal....i already use it for my business. The intent to have oil was so we could go on the occasional trip and not need a person to take car of things...so even if it was in the winter and the oil part is not as efficient. And in general I was assuming oil to heat hot water for the non heating season would be the smartest thing to do..maybe I am wrong on that. If so, then my only need for oil would be for use during a vacation...

Thanks for the info on the manufacturers mentioned, I will start research on those. and the pointer about possible needing to *open* up the machine to change over to oil and back to coal etc

If I did place the boiler outside the home ( 15-20 feet away), I am assuming an ease of use because even the fuel is outside ( no carrying tons to the basement or ash out) And also what are you all experiencing regarding fly ash over the long haul....do you get a hint of coal becoming integrated into your walls etc?

Hello Al and welcome,,
A few considerations.. can you make an accessable [from ground level] coal bin or hopper in the basement?? So that you won't have to hand carry your coal into the basement?? Carrying the ash out is bad enough, but if you have to lug the stuff both directions, it gets old fast..
If you can make an outside-fillable coal bin in the basement, I'd go with a Refurbished EFM,

The EFM boiler is a very good, proven design, that idles at low heat settings well, so it can provide hot water year round. It is also sized about right for your install, about 180K max output. Which should only be needed occasionally in the coldest winter weather.

Do a site search for 'rebuilt EFM' or 'refurbished EFM' or even EFM, you will find a lot of reading material.

If you choose to use an outside location for your boiler and pipe the hot water into the house. An EFM is not a good unit for this instalaion UNLESS a good tall chimney is installed. An EFM relies on a steady draft to keep that idling fire alive. Without a good tall chimney that will draft even in the summer months, you will have some 'out-fires' with an EFM..

An Axeman Anderson or AHS or the similar units do not need a strong draft to keep a fire idling, the design uses a forced draft that keeps the fire idling well with minimal draft, even in the summer.. My chimney is only ~14' high, and my AA 260 idles fine with a timer set to 'fluff up' the fire by running for 2 minutes every hour.

Get your favorite beverage, and a comfortable chair, and do some searches on the site, you will find lots of good reading.

Greg L

wow, another info packed answer..thank you Greg..i will start reading on the refurbished equipment as well as the AA etc. Thank you

initial research into the AA models show that there are only two...the 130 and the BIG one...since my current boiler is rated at 178k, I cannot see the 130 in my future

Al F wrote:initial research into the AA models show that there are only two...the 130 and the BIG one...since my current boiler is rated at 178k, I cannot see the 130 in my future

You don't need to match the BTUs of the current boiler as a solid fuel appliance has a continuous output unlike conventional fueled boilers that start and stop. If your current boiler is running 75% of the time on a cold day, you may be right. If it runs about 50% of the time or less, why buy more boiler than you need? Do a heat loss calculation first, you don't want an oversize boiler, the AA 130M may be just the ticket for you.

I replaced my 165,000 BTU oil with a AA130, no problems what so ever, and my house has very little insulation.

Al F wrote:initial research into the AA models show that there are only two...the 130 and the BIG one...since my current boiler is rated at 178k, I cannot see the 130 in my future

Thirty One years ago I built two building and did the heat loss calcs for each. I was planning on oil hot water BB, and installed an AA 130 in one with a heat loss of 197,000 btu's, without domestic hot water. The second was larger and I installed an AA 260, where the heat loss was 315,000 btu's. Thirty one years later, both of those boilers are still doing their job, and there has never been a complaint of being cold, or not enough hot water.
Are you reading between the lines yet? Solid fuel burning is constantly generating heat, unlike the intermittent burn of gas or oil boiler. Consequently, they have to be sized larger to give the 'instant recovery' that does not happen with coal.
Many an old timer always told me: 'Slow and steady wins the race'! Become a believer, and try to reeducate yourself about a solid fuel fuel burner. :bsod:

Anthracite: It's whats for winter!!!

Al,

I am easily doing 3,200 sq. ft. with my AA130, and it does not even break a sweat. It cannot be dual fueled thogh.

Mike

My post got lost! Here's a quick replay:

Yanche's right. 2 units are better. A high efficiency low mass oil boiler (check out Biasi on line). And an inexpensive work horse stoker like Keystoker. Boilers are optimized by engineers for either fluid or solid fuel, not both. Running the stoker year round is a good way to maintain your investment but not the only way. The low mass Biasi with an indirect DWH will respond faster all summer long. It will also save you about 50%. Really. I use about 60,000BTU/d for DHW. With oil that's about $1.25. No high mass boiler can compete with that. The Keystoker at idle+demand will cost $2-2.50/d. Not counting the extra work involved.

Ken