MPO-IQ84 or WGO-2??

dmk

Looking to replace my existing Burnham oil boiler and am looking for some professional opinions from installers (not salesmen) on which is the better product. Same goes for a Riello vs Beckett. Thanks!

BobC

The Megasteam is as good a boiler as you can buy for a cast iron unit.

I'll leave the oil burner selection to others.

Bob

kcopp

Is the system for Hot water or Steam?

STEVEusaPA

If you don't need a coil for domestic hot water, use the MPO. Triple pass is more efficient and a breeze to clean. The 84 with a Riello F3 is a nice combo.
Just make sure...
1. It's the right size as verified by a complete heat loss.
2. You install it properly, using best practices.
3. You have someone who really knows how to set up and tune a Riello.
4. If you use outdoor reset, you pipe the boiler for protection from low temperature water return.

Steamhead

The Weil-McLain boiler that is comparable to the MPO series is the Ultra Oil boiler, but they don't make one that small. Go with the Burnham.

As for burners, you can't go wrong with either the Beckett or the Riello.

Robert O'Brien

If those are my only choices, MPO by far.

dmk

I have water. I believe the WM steam model is SGO? Is the WGO not 3-pass? These 2 models (MPO-IQ and WGO) are comparably priced. 2000sqft 25 yr old Cape with all new windows and very well insulated. I did the u.s. boiler heat loss calc in came up with approximately 47,000 BTUs so I believe any boiler is going to be oversized? Trying the justify the extra cost of an indirect dhw tank...

Steamhead

The Slant/Fin EC-13P is a 3-pass boiler that's a bit smaller:

http://www.slantfin.com/wp-content/uploads/2015/11/Eutectic-Series-Catalog-Sheet-1115.pdf

Terry O

SGO is the steam version of the WGO water boiler - same castings - both are pin type boilers.

rick in Alaska

Both are good boilers, but the MPO is a three pass which has better standby loss. I don't know what kind of room you have for exhaust, but most of the places I have to deal with, the boiler room is so small you can't get a boiler in the room with the exhaust coming out the back , such as the MPO, and get the chimney clearances. In that case, the WGO is the correct answer.
As far as burners go, make sure whoever is servicing them can work on them. Almost anyone can work on a Beckett, but not many on a Riello. That said, I have only had about 6 problems with a Riello burner in about 10 years. Seems like the sealed bearings on the motor are not that great, and will go out on the pump end. Other that that, like three primary controls, of which 2 got flooded. VERY reliable burner.
Rick

dmk

Thanks for the feed back all.
Plenty of room for the flue Rick. Regarding flue - specs say minimum flue to be 6". Is bigger better when it comes to flue size?

STEVEusaPA

MPO84 flue pipe is only 5", need a 6" chimney. Bigger isn't better.

dmk

Thank you Steve. Bigger flue gets pricey!
Any thoughts on the US Boiler heat loss calc??

STEVEusaPA

I like the Slant Fin one better, but it's all about what you put in determines what you get out. But if you're in the 47K range, the smallest boiler is the best you can do. If it short cycles, then you may have to add a buffer tank.
I wouldn't increase the boiler size for an indirect. If you found the boiler couldn't keep up on the coldest day when needing dhw, you could set the control for dhw priority. But that's only going to happen a few times a year.

I don't understand this statement:

dmk said:

Trying the justify the extra cost of an indirect dhw tank...

Are you trying to compare having a coil in the Weil CantClean to an MPO and an indirect?

The only major differences will be:
-----------Positives-----------
-Ease of cleaning (MPO)
-More efficient (MPO)
-Ease of cleaning (MPO-yeah I said it twice)
-Probably unlimited hot water
----------Negatives-----------
-Expense of indirect and additional piping/installation-plus it takes up some room (MPO)
Once again, just comparing the 2 you offered up.

dmk

Yup.. Comparing the WM tankless vs. MPO with indirect. And i only mention those (2) models because the MPOIQ was highly recommended to me, but the WM seems to be the popular go-to boiler within my circle of family/friends and they are close in price. Another recommendation was a NewYorker, but I haven't seen much discussion on them. I currently have a 25 year old Burnham still chugging along but gave me some troubles last winter, and the wif don't want to be left in the cold this year. Trying to do whatever work i can myself - is the "IQ" any more sophisticated than your average boiler, that any oil tech cant handle?
Open to other suggestions/manufactures...

STEVEusaPA

Any competent pro should be able to handle it. It comes with full instructions.

rick in Alaska

Not sure why you are referring to a coil on the Weil Mclain. The WGO does not have a coil in it. The WTGO does though. So, as far as the difference between the two, they both would require an indirect.
Just clarifying.
Rick

dmk

My bad Rick, I had it wrong from the get go. That's why I'm here I guess! WTGO. The reason for this comparison was for the opinions on quality of the boilers as well as to justify spending an extra $2k on the indirect. I hadnt understood that the tankless boilers aren't 3-pass which will help with my decision.