View Full Version : Weil-McLain Ultra Boiler
11-13-2004, 09:11 PM
I'm thinking of replacing my current boiler with the Weil-McLain Ultra 80. Does anyone have any experience with this company and this product? I'm impressed with the ability to derate the output down to 20% automatically to match the demand. As they explain it, this also increaes the efficiency (more surface area per heat density = greater absorbtion of available heat - less out the flue when throttled down). Based on my heat load evaluation, I need a steady state 28K btu on a -10 degree day. So, the 80K unit would give enough to warm the place up and make some domestic hot water and not be stressed, and would normally run at much lower than the maximum available output except when making hot water for showers/baths, etc.
I have a hydo-air system as a backup (was the original heat system), suplimented with in-floor radiant heat system as the primary system for most of the house (actually a townhouse - my neighbors help to keep me warm!).
10-09-2005, 09:19 AM
I have an Ultra 80 installed supplying Domestic hot h20, radiant floor and baseboard heat. When it works.. it works great! Quiet, effecient. However, it has been installed for only 2 years and has left me without heat or hot water twice and everal service calls for minor things also. Not what I expected from a high end boiler!
The failures come from a poorly designed outside air intake inlet. The inlet happens to be just about the vent motor. Well, when the cold outside air hits the nice warm air inside the boiler in condenses.. and drips on the motor... shorting it out. This has happened twice and WeilMclain claims they have no knowledge of a design problem... The installer does not stock the part.. so I'm without heat or hot H20 for a week or more... :( Not good in Michigan winter! Had I known about this, I would have gone for the more expensive, yet apparently more reliable and TESTED Viessmam. Good luck. Hope this helps.
10-09-2005, 09:35 AM
Don't do boilers or such down here in sunny S. Calif. But, 28K BTU sounds like a very small number. It is not unusual to see a 70K BTu (input) furnace in a 3 BR/1800 sq. ft. house.
10-09-2005, 11:41 AM
I'm in a special situation - a townhouse with only two outside walls and not too many windows, so the heat load calculation looks funny until you see the situation. I've got a 32Kbtu water-air heat exchanger in the air handler that works fine to keep the place warm on a -10 degree day.
Weil- McCain came out with an updated version of the Ultra boiler this year, I wonder if the issue mentioned was addressed. With the cost of energy today and into the future, a really efficient heat source becomes more of a necessity rather than a luxury. WIth their modulating gas valve, they can throttle the boiler down to 20% of max, and increase efficiency (larger heat exchanger relative to input energy at low fire point) to a stated 98% - the extra 5% or so over their already high efficiency seem like a great feature.
Maybe I need to talk to the rep and see if I can find out what changed. I do know that they changed their air intake, and have one model that uses a concentric section (primarily for roof penetrations) that could help solve some of that by preheating the intake air, reducing condensation. I planned on a wall penetration, though, and I don't know if that version would be accepted or allowed.
Any more thoughts are welcomed. I wanted to get this resolved this summer, but have been away on travel (I won't be home again for any significant time until after Thanksgiving).
12-29-2007, 03:18 PM
I installed an Ultra 155 myself. It replace a 1907-vintage boiler. I also integrated it with domestic HW (indirect heating). It's been working great for a year and saving me money.
It was a fun project but probably not for a novice. You need to know plumbing and electrical, including relay logic diagrams. You need to have the required auxiliary controls. FYI, I'm a chemical engineer, not a heating contractor.
12-29-2007, 03:48 PM
You might have missed the dates on this thread.
Ironically, Jim (JdNashua) went with a Buderus as I recall..from what he says, he's pretty happy with it.
The suggested Viessman is even better..I am looking into the Weil Maclains, but I think they are basically trying to keep up with the high efficiency market.
Viessman being at the top of the list, Buderus, Baxi Luna...and Munchkin.
Also, obligatory disdain expressed for the DIY boiler, but at least you knew better....
10-25-2008, 04:56 AM
My Ultra is a huge disappointment. It intermittently shuts down. It is not much more energy efficient than the 25 year old boiler it replaced. I made a big mistake buying Weil McLain.:mad:
12-14-2010, 11:12 PM
Jim, having seen your post from a few years back, i wonder if you chose the W-M boiler at all? What was your consideration?
12-14-2010, 11:18 PM
the Buderus has been working great. the Viessman probably would have, too, but they wanted about $3k more, which I couldn't justify.