high efficiency gas boiler - brand advice

Jris

Folks, I'm in the midst of purchasing my first home (1.5 stories, unfinished basement, approx. 1300 sq ft) in Boston. One of the upgrades I'm executing is a new high efficiency gas boiler & indirect water heater; the current boiler is a 30+ year old Burnham (water heater has a few years left, but when in Rome...). I'm tying to gather data on reliable brands for a >= 95% efficiency unit. I've had one plumber recommend Burnham (again), another Lochinvar, and - unfortunately - I'm out of my depth here. Any advice on what brands to focus on or avoid? This being Boston, I'm comfortable paying for quality.

EBEBRATT-Ed

You will get many different answers. The best decision is usually the best installer using a boiler he likes. The best boiler installed by a slob is a poor choice.

Viessmann is usually considered the Cadilliac
Lochinvar
HTP
The list goes on

Jamie Hall

Installer first. Then worry about the boiler. If the installer is good, the boiler will be. If the installer is so-so or bad, it doesn't matter what the boiler is -- the result will be ... unfortunate.

Steamhead

What model Burnham is in there now?

Jris

Thanks, all. I'll grab the Burnham model that's in there now later this week (next time in house - stupidly blurred the photo I took at first, but it had a 1988 install date...)

Zman

When you look carefully at the residential condensing boilers on the market today, you notice that at least 90% of them are using the same 2 stainless steel heat exchanger designs. Models like the Lochinvar KHB series utilize a "water tube" design which has a proven track record of over 30 years. The Lochinvar WHB series utilizes a "fire tube" design which has been on the market for at least 15 years with great results as well.

As for the other < 10%, proceed with caution. Some of the "tube in tank" models from HTP perform quite well, Aluminum heat exchangers can be problematic.

When you look at the brochures for most models available, you will notice that most are either firetube or watertube. In fact, many of the manufactures source their heat exchangers come from the same factory.

When you are looking for recommendations, don't get too hung up on the brand. A correctly sized boiler which is installed per manufactures instruction is the most important part. The contractor should be performing a heat loss calc to size the boiler, they should install per instructions and tune the boiler with a combustion analyzer.

SweatHog

Although no boiler is perfect, I don't get the love for Lochinvar:

https://forum.heatinghelp.com/discussion/comment/1586451#Comment_1586451
&
https://forum.heatinghelp.com/discussion/180178/lochinvar-recall

Jris

Yeah, I noticed the Lochinvar recall - definitely a red flag, and others have hinted at some difficulties with the brand before.

Zman

@SweatHog @Jris
I am going to have to go ahead and uh... disagree with you on that.
All condensing boilers occasionally have issues with harmonics from combustion and sometimes gas piping. It usually can be eliminated when the instructions are followed and combustion analysis is performed.
As for the recall, we are talking about 7 cases out if approx 40,000 units. I respect Lochinvar for erring on the side of safety. It should be a pretty simple fix.

flat_twin

Highest efficiency comes when the boiler water returns to the boiler at less than 140 degrees and lower is better. A survey of your emitters, baseboard fin or cast iron rads should be done to determine if this is possible. Sometimes the simpler, less expensive, slightly less efficient boiler is the better choice.

SweatHog

@Zman. Yes, boilers occasionally have issues with combustion. But in Lochnivar's case the problem was compounded by the absence of combustion adjustment directions in the service manual discovered by @OaklandNS where he said the Lochinvar manual: "provided no provision for adjusting low-fire combustion. It appears that the service manual has since been updated on Lochinvar's website to recommend adjusting the offset on the gas valve by very minor amounts to dial in low-fire combustion." Lochinvar's have nice features. However, they update their product lines so often it's become and invitation to quality control issues.

Zman

@SweatHog
We can agree to disagree on this one.

I like that Lochinvar is constantly improving their products. The modulating control over the boiler circ for example has been a long time coming. Personally, I find the controls very intuitive.

You seem to be basing your judgment, at least in part on a homeowner's post where they are confused about how to adjust the offset on one of the most common gas valves on the market.
To me, it makes sense to discourage homeowners and most techs from playing with the offset screw. Improper adjustment can make a hot mess of things.

mazz

Thanks so much for all of your comments & advice ,my wife & I are currently having inspections on a 23 year old log home we plan to purchase that has 2 Weil-McLane boilers w/ 1 indirect tank , each boiler is 175,000 BTU’s ...cast iron with stainless steel venting & only 80-82 % efficiency. They are both located on 2nd floor & used to heat a radiant PEX tubing 4,200 sq ft bottom slab concrete floor with 4-5 zones.....we had a bid of approximately 20,000 $ to replace both with Lochinvar boilers & new pumps ECM ‘s , which the contractor said would save about 250-500 per month in energy cost. Both original Weil-McLain’s are LP . Would appreciate any advice on this .
Thx Mazz

hot_rod

I'd sure get that $250-500 per month savings in writing

Ironman

mazz said:

Thanks so much for all of your comments & advice ,my wife & I are currently having inspections on a 23 year old log home we plan to purchase that has 2 Weil-McLane boilers w/ 1 indirect tank , each boiler is 175,000 BTU’s ...cast iron with stainless steel venting & only 80-82 % efficiency. They are both located on 2nd floor & used to heat a radiant PEX tubing 4,200 sq ft bottom slab concrete floor with 4-5 zones.....we had a bid of approximately 20,000 $ to replace both with Lochinvar boilers & new pumps ECM ‘s , which the contractor said would save about 250-500 per month in energy cost. Both original Weil-McLain’s are LP . Would appreciate any advice on this .

Thx Mazz

What's your locale?

mazz

Wei-McLain 175,000 LP boiler 23 years old non condensing