Boiler replacement. Currently 142K BTU boiler, heat loss calcs say 56K BTU?!?!

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Old 02-19-17, 06:58 PM
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Boiler replacement. Currently 142K BTU boiler, heat loss calcs say 56K BTU?!?!

I currently have a New Yorker Oil fired boiler Model number S-142-AP. It is 142,000 BTU Gross Output. We have a forced hot water heating system with baseboards. The boiler has a domestic hot water coil in it. The domestic hot water coil is currently used to pre-heat water into the hot water tank. We do not need the coil though. We don't run the boiler in the summer and just use the hot water heater by itself.

Our house was built in the early 1800's but has been updated and has modern fiberglass insulation and even a spray foamed 2x6 wall in one room. The only room without insulation is the upstairs bathroom. The attics are insulated as well. The house is a two family and the boiler was used to heat the back apartment at some point, but that zone was dis-connected prior to when we purchased the house 10 years ago.

I have run the Slant Fin heat calculator and it is telling me I only need a 56k BTU boiler. It also tells me I need a total of 98 feet of baseboard. We currently have 85 total feet of baseboard. The baseboard lengths make sense to me as a couple of rooms have always been hard to heat and take a long time to warm up. These rooms are coincidentally short on calculated baseboard lengths.

I have triple checked my numbers, I even have used cold partition lengths for walls next to un-heated rooms. With this calculation I am thinking about using a Buderus G115WS3 74,000 BTU boiler. What are your thoughts on this boiler and the heat calcs?
 
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Old 02-19-17, 08:05 PM
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You only have 47K of baseboard in the home. Unless your adding baseboard there is no reason to go bigger then a 50K btu boiler.

And thats if the baseboard is in good condition with no dust or blocked by furniture. Also all fins are straight..

Whats the total sq ft of home?
 
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Old 02-20-17, 05:13 AM
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It also tells me I need a total of 98 feet of baseboard. We currently have 85 total feet of baseboard. The baseboard lengths make sense to me as a couple of rooms have always been hard to heat and take a long time to warm up. These rooms are coincidentally short on calculated baseboard lengths.
These problems are not related to boiler size, they will persist if not remedied as a part of the new boiler install. Is it your intention to add more baseboard?

The boiler has a domestic hot water coil in it. The domestic hot water coil is currently used to pre-heat water into the hot water tank. We do not need the coil though. We don't run the boiler in the summer and just use the hot water heater by itself.
Something to keep in mind is that, during the winter months, a stand-alone hot water heater/tank is more often pushed to its limits (because it takes more BTUs to heat up the colder incoming water).
 
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Old 02-20-17, 06:17 AM
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Than you for the replies! I appreciate the questions/feedback.

lawrosa, the total heated area on our side of the house is 1717 ft^2. This is what I measured for the calculator. It doesn't include closets (which I put in as cold partitions), the upstairs hallway, or the partially heated/non living space basement. The apartment in the back has it's own separate heating system. Do you need the closets and hallway added in?

Rockledge,

I do intend to add baseboard in those problem areas. I am also finishing the downstairs bathroom so part of the 98ft that the calculator is giving me is due to that. So I will most likely end up being at 98ft of baseboard once all is said and done. As for the water heater, it is an old Vaughn unit that is not looking too good. So I am hoping to gain some efficiency with a newer one to offset the winter losses. But point taken and I will still consider a boiler with a domestic coil for my evaluation.

I should also mention that we supplement our heating with a wood stove. In years when oil prices are high we will tend to use it more. However the wood stove works well to heat the living room/dining room, kitchen and the upstairs. It does not heat the other bigger living room, bedroom, and bathroom (all downstairs) well. Not to mention when the power goes out I like having it there as backup.

Thanks agian!
-Paul
 
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Old 02-20-17, 06:48 AM
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Cutting the firing rate raises efficiency. If your existing boiler is reduced to 80,000 BTU it may be just as efficient as a new Buderus G115WS3 74,000 BTU boiler which is rated at 86.7%. Why spend $2,000 plus parts and labor for the same BTU's?

A good cleaning and smaller nozzle might be far more cost effective.

http://www.supplyhouse.com/Buderus-G...00_SupplyHouse

While you never want less, boiler BTU output is typically far more than an existing hydronic heating systems can deliver.
 

Last edited by doughess; 02-20-17 at 07:26 AM.
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Old 02-20-17, 07:05 AM
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doughess,

Thanks for that idea. I hadn't thought of that. However, the current boiler needs to be replaced. For the past two years when I have had it cleaned I have been told it needs to be replaced (these are friends of mine so I trust their opinion). It is rusted pretty bad and it is weeping water through the rust by the domestic water inlet (not in the copper pipe but in the stove). Within the past week smoke has started to puff out from in between the sheet metal cover on the side. I have had to seal this up to prevent this from happening. I haven't taken the sheetmetal cover off yet but I imagine there is a small hole straight into the firebox somewhere on the side.

-Paul
 
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Old 02-20-17, 08:50 AM
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Along with good efficiency, a key reason I hang on to my 50 year WeilMcLain, is that with two big doors, it is easy to clean and work on. Irrepairable leaks are the only reason it would be retired.

A major factor in buying a boiler should be how easily and effectively it can be cleaned. Some boilers require a long tooth brush to clean and it is usually hard to access many places to do a good job. Others have plates to unbolt and remove to clean. A real pain... As they get dirty the efficiency goes down and down.

If you get a new boiler, measure the stack temp and use it as a benchmark for future cleanings and how effective they were.

Never had an exhaust leak in the combustion camber but have used furnace cement fill in gaps in the cast iron segments.
 

Last edited by doughess; 02-20-17 at 09:20 AM.
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Old 02-20-17, 06:07 PM
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doughess,

What do you recommend for a boiler that is easy to clean? I will take your advice on measuring the stack temp.

-Paul
 
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Old 02-20-17, 07:29 PM
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Am not really up on new boilers. The one with the removable steel plates was actually easier to clean than others but do not recall the brand. Those with burner mounted on swing out doors are a plus.

Just be aware of the issue when shopping.

A side issue is to use flexible fuel hoses to the burner. Makes it a easier to pull out and service burner without an oil mess.

Also see some of my posts on wiring a digital elapsed time clock to the burner. It is a good way to monitor actual performance and provides data to tweak the system.
 
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Old 02-20-17, 08:33 PM
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Get the smallest oil boiler you can... But you will not find one lower then 60K btu I believe... This condensating unit would maybe be my choice over cast iron.


Peerless® Pinnacle® (Oil)
 
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Old 02-21-17, 09:06 AM
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If hammerpe33 buys a boiler 60K boiler and over a few years it looses efficiency, it might not be adequate for the estimated 56K load on a cold day. Better to buy a bigger boiler and use smaller nozzle for higher efficiency. Then if he need more heat put in bigger nozzle.

The higher efficiency of condensing boilers is worthwhile for radiant heating systems. There 80F, 90F or 100F water is usable. On baseboard and other types of radiator systems 180F may be required to meet heat load.

Try crunching the numbers on your existing hydronic system. My 1” copper tube system is 100K btu max, yet the boiler is rated 145K btu ??? Now firing at 80K btu and burner runs 8 hours/day at design temp.

Condensing may be 92% efficient when 80F hydronic water is adequate in baseboards. On a cold New Hampshire day it will be in the non condensing mode at 88% or less.

There have been articles in trade magazines about the poor payback of high efficiency systems for some applications. Unfortunately may see the 92% and and think no further.
 
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Old 02-21-17, 01:43 PM
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On baseboard and other types of radiator systems 180F may be required to meet heat load.

On coldest day of year..


it might not be adequate for the estimated 56K load on a cold day.
He only has 47 K of basboard..

Condensing may be 92% efficient when 80F hydronic water is adequate in baseboards. On a cold New Hampshire day it will be in the non condensing mode at 88% or less.
Shoulder seasons he will save. And with condensating if he over radiated he can run lower temps..

His 1700 sq home requires a boiler from 43 K btu ( well insulated home to ) 60 k btu with a drafty home.

That oil boil I kinked to is 64K btu..

Doing the math he can add 32 ft of baseboard to his existing system if he needed. So if rooms are under radiated add 5 ft here, 10 ft there, etc.

That peerless is pricey.. If you want to save on cost then install something else..

Biasi..

B-3 - Biasi B-3 - B-3 - 58,000 BTU Output Oil Boiler w/ Riello Burner
 
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Old 02-21-17, 05:32 PM
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Thank you guys for all the feedback. There is one variable that I neglected to enter into the equation.

B + DHW = HWHL

The right side of the equation = Happy Wife Happy Life.

So I think I need to stick with a DHW coil. My wife is boderline about the hot water in the summer (without the boiler and just the hot water heater) so in the winter, when the incoming water temp drops my life and wife would not be happy. This limits my choices but this one is at the top of my list:

WTGO-3L 99,000 BTU Output Gold Oil Boiler w/ Tankless Heater

The question I have is: What is the difference between the WTGO-3L and the WTGO-3LR? The Mclain website says it is a reduced burn rate. It says that I will need a smaller nozzle. So I am assuming I can buy the WTGO-3L and reduce the nozzle size to get the lower burn rate??

Also the website lists this Burner as optional equipment. What is the advantage to using this burner?
 
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Old 02-21-17, 06:03 PM
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H,
The WTGO-3LR fires a .80 nozzle for a net rating of 85,000 BTU'S
The WTGO-3L USES A .95 nozzle for a net rating of 100,000 BTU'S

It is exactly the same boiler you just use a different nozzle for the lower rating which you can change at any time and only have to adjust the air setting because of the higher fuel rate. Very simple but should use gauges. The boiler has 14.9 gals. of water.

It does not come with a burner from Supplyhouse.com but is sold separately. Generally you can choose what burner you want but you would have to call them to see what they offer.

The Beckett if the most homeowner friendly but you can also use a Carlin or Riello if you prefer.

If you get this boiler from a contractor it will come as a package with the burner installed. These are things that people don't see or care about but the contractor will use the burner he is familiar with. Some people have a preference but they are all good.

If you go on that sight you mentioned click on the boiler, scroll down and then click on user guide and keep scrolling and you will find al the info on the boiler. Scroll almost to the end to find the specs for different size boilers to compare.

Hope this helps a little.
 
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Old 02-23-17, 05:50 PM
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You can also look at the MPO-IQ rated at 64K. Very serviceable due to the entire front swings opens. Add ODR plug in card for even higher fuel efficiency. They can be ordered with a wired or wireless OD sensor at the same price. No up-charge of the wireless sensor.
If LWCO is required in your state also a plug in card.
Very similar to the Buderus design as both are a 3 pass boiler but the MPO-IQ can return cooler water (100F) without special controls. Bypass piping protection built into the boiler.
Get the Beckett, Carlin or Riello burners. Beckett is usually burner of choice but Carlin is quieter and easier to adjust.
I would not do a coil as it is the most expensive way to make domestic hot water. If water heater goes replace with an IWH tank.
The boiler is also available with a Grindfos Alpha circulator at no extra charge. These pumps will use much less electric.
MPO-IQ84 - Burnham MPO-IQ84 - MPO-IQ Series 64,000 BTU Output Oil Fired High Efficiency 3-Pass Boiler
 
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Old 02-23-17, 08:28 PM
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hammerpe33 has not said what type of burner is on the current/old boiler.
Maybe it could be used on new boiler? Even old Beckett AFG's can use nozzles from 0.50 to 3.00 gph.

With many people converting to gas there are good used ones available. Last year I bought a nice AFG for $90 on ebay as spare.

In winter I use tankless coil and circulator to feed separate water heater that is oil fired in summer. Response is good with control set at 3 degree delta. This is efficient set up that avoids issues of two burners on common chimney. Valves allow either system to run independently if necessary.
 
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Old 02-24-17, 05:47 PM
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rbeck,

That is a nice boiler. I will take a look at it in detail. Thanks for the tip.

Doughess,

I have an old beckett burner I'll get the model number and post, I dont have it on me right now.

Thanks again for all the help!

-Paul
 
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Old 03-05-17, 05:24 AM
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doughess,

Here is what I have for a burner now:

https://www.dropbox.com/s/byqfyneywz...81132.jpg?dl=0

It is a frankenstein with Beckett and Carlin parts. I had someone come and service it one fall and they replaced the old beckett parts that needed replacement with Carlin parts.

I remembered that we switched from Oil to NG at one of our apartment buildings and I told them to leave the old burner. I picked it up this weekend and is shown here:

https://www.dropbox.com/s/oy7s6536ho...81153.jpg?dl=0

Seems like this one is in pretty good shape. I haven't checked the nozzle size but imagine it is pretty big as it was for a huge old coal boiler that was converted to oil. We have a pretty big NG Burnham there now.

I will let you guys know what I go with and start another thread with install pics. I'm sure I will need some advice/help along the way!

-Paul
 
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Old 03-05-17, 05:43 PM
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rbeck, or anyone else... Can you tell me if the Burnham MPO-IQ has an aquastat built in??? Or do I need to purchase one in addition to the boiler?

-Paul
 
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Old 03-05-17, 05:59 PM
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rbeck, or anyone else... Can you tell me if the Burnham MPO-IQ has an aquastat built in??? Or do I need to purchase one in addition to the boiler?


Yes has aqua-stat. and you can get card add ons for just about anything. Outdoor reset. low water cut off, etc etc.

As stated will accept return temps as low as 110F
 
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Old 03-05-17, 06:01 PM
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Also a note I believe you will need to line the chimney....
 
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Old 03-05-17, 06:10 PM
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See brochure here

http://s3.supplyhouse.com/product_fi...4-brochure.pdf
 

Last edited by lawrosa; 03-05-17 at 06:26 PM.
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Old 03-06-17, 04:58 AM
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Also a note I believe you will need to line the chimney..
I looked in the installation manual and it said that I only needed a minimum of an 8" x 8" Chimney. The Buderus manual is even less detailed (it has no picture or drawing) and says the same. Is there something I am missing?

-Paul
 
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Old 03-06-17, 12:00 PM
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Paul,
An 8x8 chimney flu is a stanard size for a 1 flu chimney but they do come in other sizes. As long as you have an 8x8 you should be fine. I think what lawrosa might have been concerned with is the draft and stack temps.

With a regular boiler your stack temps are higher than a 3 pass boiler like you are looking at. With a 3 pass boiler your stack temp will probably be around 350, maybe less, which might not be enough to heat a large chimney flu in order for you to pull a draft. If your stack temp is not hot enough to create a draft then you must use a liner in the chimney to reduce the size to be able to heat the flu in order to pull a draft.

I have installed Buderus and have run into that situation. Buderus has baffling in there boilers that can be removed in a certain order to acquire higher stack temps to combat that problem.

Didn't mean to imply I knew what L was thinking but I hope this helps a little.
 
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Old 03-06-17, 04:12 PM
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Buderus has baffling in there boilers that can be removed in a certain order to acquire higher stack temps to combat that problem.

Didn't mean to imply I knew what L was thinking but I hope this helps a little.
Thats where I was going with it. The MPO has baffles also..

Condensation on the tile chimneys will destroy them..
 
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Old 03-07-17, 06:52 AM
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Excellent thread, good discussion . I installed a Biasi/Reillo, and am very happy with them.
Sid
 
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Old 03-12-17, 05:41 PM
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Guys,

I measured my chimmney. At the cleanout it is just shy of 8.5" across. At the top it is 6" x 6". Here are some pics from the roof...

Pic 1
Pic 2

I will cost out a liner just in case, I know the liner for the other chimmney for the wood stove was a couple grand. I understand that liner is stainless steel and needs to be able to take really high temps, so I am guessing this liner will be less. In any event I will have to look at some non 3 pass boilers in case the liner puts me over budget.

On the baffles, if I take out baffles does that reduce efficiency? What is the down side to taking out the baffles?
 
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Old 03-13-17, 08:18 AM
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A 6” plus chimney should be more than adequate for new Burnham burner firing at 64,000k with 5” outlet.

One question not answered is what is current chimney construction? Many existing chimneys are lined with ceramic tile pipe that have no problem with condensation and were designed to handle +600F stack temps.

Many of the reviews of stainless steel condensing boilers have horror stories of the SS being eaten away. Chimney liners may not last. Saw no reason to justify one here.

Raising combustion chamber draft (lowers efficiency) to deal with chimney condensation sounds counter productive.

Removing boiler baffles is the not best way to deal with draft issues.

If the correct draft over fire draft is good, would not worry about existing chimney.
 
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Old 03-13-17, 01:30 PM
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One question not answered is what is current chimney construction? Many existing chimneys are lined with ceramic tile pipe that have no problem with condensation and were designed to handle +600F stack temps.
This chimmney is original to the house, most likely. The top 15 feet or so was re-done about 6 years ago. I have no idea if there is a ceramic liner. If I had to guess it is just brick and morter. When we had the chimmney re-done he may have put in some ceramic liner on the 15 feet he replaced, but I don't know. My guess it is 8x8 all the way to the top or to the beginning of the replaced section. The very top exit is 6" x 6".
 
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Old 03-13-17, 01:53 PM
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Terra cotta is much more likely as a flue liner than ceramic. I would think it would have to be a very old house, more than sixty years old, to have an unlined chimney. If you are not sure then spending $100 for a chimney inspection from a bonded chimney sweep might be wise.
 
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Old 03-13-17, 02:13 PM
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I would think it would have to be a very old house, more than sixty years old, to have an unlined chimney.
Yes it is very old. Early 1800's....
 
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Old 03-14-17, 07:44 AM
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Here in New York chimney sweeps do more than clean out your chimney. One found a phantom squirrels nest in mine and said it was clogged. I sent him away empty handed, no money or squirrels nest.

Hammerpe33's old 145,000 BTU system was doing OK on that chimney. With a 50% lower firing rate on his new burner there is time and room to evaluate the setup.
 
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Old 03-14-17, 09:01 AM
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That pic of your chimney shows a clay liner and is the smallest they make and is a standard chimney liner for a single flue chimney and if it is in safe working order will be fine for a 3 pass boiler or any boiler.

I once installed a Buderus 3 pass with a fairly long run to the chimney which affected the draft and stack temp. As per instruction on the Buderus manual I removed a couple of baffles which got me the readings I was looking for with no appreciable decline in efficiency.

The baffles are there to remedy different field situations and still acquire the best results.

I mention Buderus because that is one I have experience with. The Burnham at the time did not have the MPO but I'm sure it's the same situation.

A few years back Burnham had serious problems with their V7 and V8 boilers and replaced them with the MegaSteam 3 pass heat exchanger which I have installed and they are excellent boilers.
 
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Old 03-14-17, 10:39 AM
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Guys,

Many thanks for all of the help and suggestions. I have decided on the Burnham MPQ-I84. The cost of the Buderus, once you factor in the aquastat and logomatic (I am getting the outdoor reset IQ card) the Burnham is cheaper and will fit within our budget. I will start another thread for the prep and install. I may have some questions before I purchase the boiler and I will post them here.

-Paul
 
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