We are doing a major home renovation - half new, half updated old construction. We are going with an underfloor radiant heating system. We need to finalize our selection of combination (gas) heat source. We want the same boiler to do both domestic hot water + hydronic heating. We are tight for space, and the heater will be located in a utility closet close to the middle of the house, so noise is a factor.

We've found Buderus, Munchkin, and today learned about a "Phoenix" unit from the same folks who make the Munckin (Heat Transfer Products - http://www.2hsc.com/residential/manufacturers/phoenix.html).

There's apparently a pretty significant cost difference between the Buderus (top shelf as far as we understand) and the Phoenix. The Munckin seems to be in the middle.

The Buderus and Munchkin would form the heart of a similar (heater+tank) system, and the Phoenix would be a rather different solution (all in one).

Does anyone have any experience / recommendations / warnings about any or all of these?

We are trying to save money where we can, but don't want regret going with the cheaper alternative.

I look at the Phoenix and see "old school" design, whereas the Buderus, and to a lesser degree the Munckin, seem like better engineered, more modern solutions. (I'm a mechanical engineer by training, so that's a strong factor for me.)

Any advice would be greatly appreciated.

Thanks a ton,

-Bruce
San Francisco Bay Area

Geothermal has the highest initial cost but the money goes directly into the value of your home. Geo also has the lowest operating & lifecycle cost and highest user satisfaction rate.

Did I mention GREEN?

SR

I would stay away from the munchkin with its Gionanni Ht Exh and it's inherent heat exchanger problems, cleaning requirements and high head waterway design.

Buderus is a fine boiler along with the VIESSMAN (The Mercedes) but, for the best value and functionality, you should also look at the Triangle Tube Prestige boiler, coupled with a Smart indirect tank.

http://www.triangletube.com/

Based on recent developments with problems of aluminum boiler block designs having problems dealing with acidic condensate, requiring proper PH, and difficulty with higher temps (producing domestic hot water), I would stay away from those designs if given the choice.

Besides the minimum turndown being 40,000, way to much for most residential homes with multi-zones to benefit, and it weighs over 500 lbs., is only 93%+ efficient missing Energy Star requirements for rebates, what else am I missing?

I've not heard of Viessmann - from the little research I just did, it does look to be the "Mercedes" (Porsche?) option - people seem to have consistently high opinions of it, and consistently high sticker shock as well. Have you heard one of these units firing - is it quiet?

It looks like dealers are few and far between out here in CA (like, Reno NV) - which probably explains why I haven't seen it locally.

I'm not familiar with the "Ray" - I'll research that one as well.

ZL700 - I've read some posts about the Munchkin boiler regarding corrosion - however I read on the manufacturers website that it is "Durable all stainless steel 316L heat exchanger design" (from: http://www.htproducts.com/products/munchkinvwh/index.html ). Are there Aluminum parts that corrode that aren't actually in contact with the water? Did Munchkin change their construction along the way?

Off the top of your head, do you have a list of which boilers use which construction? I'm a big fan of 316 SST, so I clearly understand the advantages of that type of construction.

Thanks all!

Bruce

The Triangle Tube Prestige uses a downfired self-cleaning fire-tube heat exh with about the largest mass and lowest pressure drop out there. Mine and most peoples favorite, beside Viessmann. Viessmann offers mixing controls integrated with the boiler which is appealing to high end radiant installers.

Stay away from Weil McLain Ultra (aluminum) along with Monitor, Baxi, Trinity, and a few others that dont come to mind. (IMO)

Utica/Dunkirk,Burnham/Crown & HB Smith make OK hi-efficiency boilers, just not as popular.

The Viessmann, Triangle Tube and Buderus are all bullet proof boilers and yes are quiet. You could be standing next to it and have to put hand on pipes to know it's working.

Care to share in greater detail your comments re: Lochinvar? We are looking to replace our 1970s boiler and Lochinvar had been/is tops on the list. Certainly want to go into this knowing all that we can, so if you can further elaborate I would appreciate it.

If I was to buy a floor boiler this would be my first choice but not my favorite overall when weighing price, features, value, service and space required.

As all installs, proper install is key. The installer must understand piping, 9 times out of 10, primary/secondary piping is required to allow boiler to maintain proper flow, irregardless what the heating system or zones are doing.

I spoke with a helpful guy at Pacific Energy Sales here in Santa Cruz CA today - he ballparked the cost for a Viessmann Vitodens (WB28-32) at about $10K, the Buderus (GB142-45) at about $7500, and the Lockinvar Knight (I didn't scribble down the model number fast enough) at about $5K. I hadn't researched the TT Prestige at that point, but might call back to see if he can ballpark that one as well. But clearly, there's a pretty significant difference. Do those numbers sound anywhere near right for those out there in the know?

I'm going to check with my contractor and see if the TT Prestige is a possibility. If not, then it's probably the Buderus. If I win the lottery in the next month, then I'll take the Viessmann.

Judging by the lack of any opinions on the "Phoenix" all-in-one unit, I think I'm going to back away from that option. I couldn't find anything out there on the interwebs on it either....

-Bruce

Sayde, what size tank?, unless you have a big draw demand a indirect can be the same size and usually smaller because of the higher input of the boiler resulting in recovery rates 2-3x of a standard tank.

Adding an indirect involves the tank, accy's, circ pump and pipe/fittings. A 50G located next to boiler shouldnt be over a $2000 adder.

That price would be around right with the usual old house install and mammoth boiler removal.

no experience w/ the Ray, though I'm partial to the cast iron heat exchangers. Seems aluminum can have problems if water is poor quality...these are just our observations when talking w/ installers. also like some of the onboard controls, seems similar to the EK. it must be the yellow! I think AFUE is bunk and doesn't measure true system performace, though, can't argue about the rebate issue.

AFUE is needed as a baseline, whether the selection or install can hit it is a diff story

http://www.fueloilnews.com/uploads/newstrends/2007/0907_trends1.asp

actual report

http://www.pubs.bnl.gov/documents/41399.pdf

If you install a condensing boiler in a radiant panel application, or large mass radiation or convection that will allow lower temps, have considerable operation times and it is installed optimally, you will see the efficiencies published or higher with the lower water and operating temps. If you raise the temps to 170-190 as so many copper convection baseboard systems were designed around, absolutely not will the efficiencies be achieved, but as good as or better than the rest. The bigger value here is the significant less standby loss associated with a larger cast iron boiler that was fired, is now full of hot water and sitting idle, with ambient and stack losses occurring.

The most important thing to gain by installing the mod/con boiler in any application and to obtain near or at published efficiencies is too run it at a temp to satisfy the space requirements and no warmer. This is done with an outdoor reset. The handicap that most cast iron boilers have is the minimum advised run temps, in order to avoid, condensing, shock and low flue temps resulting in draft and chimney problems.

I am curious why you don't like the Trinity boiler? One of the quotes that I got is for that boiler running two hot air zones with hot water coil and a third zone with radiators.

Also, can anyone recommend good installers in Central/North Western NJ? (Rt 78 Corridor) Thanks.

Plagued with numerous problems in the past, requiring excessive cleanings and gaskets required to open up heat exchanger is gets costly, and the combi units were the worst out there.

They say they have fixed all their problems, but then again I don't know anyone using them anymore to substantiate that claim.

Option 1 - Munchkin MC80 boiler
Option 2 - TT Prestige Solo 110

I'm walking in an area I'm not too familiar with and would greatly appreciate any insights from anyone who has gone down this path.

They both said that in addition to the boiler I will need a separate hot water heater for the domestic use. Is that accurate?

Thanks, Michael