Boiler quote advice?

jpod3311

Hi All,
I have a 68 series Weil Mclain oil boiler (151 MBH output) that was installed in 1992, and is starting to show its age. The heating is two zones, one for the hot water and one for the house. I'm considering getting it replaced before winter (I live in Maine), and reached out to two companies for quotes. Both are locally owned, fairly small companies. I received quotes for vastly different amounts (~$ different), and was wondering if anyone out there could help me make sense of the "better" value. I want to make sure what I put in is going to last, and that it will be easy to maintain in the coming years.

Company A:
-Replace boiler with Pensotti Quatech DK-2-5 boiler (151 MBH output)
- install circulators on supply instead of where they currently are on the return
- Install brass circulator flanges with shut offs
- Various plumbing to install new boiler

Company B:
-Replace boiler with Biasi B10/4 (94 MBH output)
-various plumbing to install
-install circulators on supply instead of return

I guess my main question is, is Company A ripping me off, or is Company B a hack job that I'll pay for in the long run?

Thank you!
Joe

Intplm.

Hello @jpod3311

First. Please know that we do not discuss pricing here. So, please edit your post.

Do you have a service company relationship with either of these two companies? If so, talk to them a bit more about what they are offering. Total package!? Service warranty items etc.?

If you have a service company already and it isn't one of the two you mention give them a call.

Maybe get a third quote from another company and really sit down and ask them what they are offering in a total package.

Can't say that one company is ripping you off or another is a hack. I agree that a large difference and costs can send up a "red flag".
Try getting more information and go from there.

JakeCK

Ask them how they sized those boilers. There is a 57k btuh difference between the two. That difference could almost heat my house on the coldest day of the year. That'll be a big part of the cost difference right there.

jpod3311

Hi both,
Thank you for the thoughts, I appreciate them!

@JakeCK - The current boiler is sized at 151. I have a ~1200 sq ft home, single story, basically a big rectangle. Before I bought it it didn't have insulation in the walls or attic. Insulation has been put in the walls, and 40" of cellulose insulation in the attic.

I did ask both because it's a big difference, you're right! Company A said "it's currently 151 so that's what we went with" even though I pointed out the difference in insulation when that one was installed. Company B said "I have 30 years experience and have no doubt a boiler with 94 output can heat your home."

@Intplm. - apologies for pricing, I've edited my post to (hopefully) make it acceptable. Thank you for the thoughts. I do have a service relationship with company A, and to be honest was hoping to use them for the install. Company B has good reviews but I have not used them, and reached out to them for the purpose of a comparison quote, didn't expect it to come in so much lower! I've contacted a third company to see where they fall, which hopefully will be helpful, as well.

Much appreciated,
Joe

STEVEusaPA

Proper heat loss is the only way to determine the proper size of the boiler, and I can tell you don't need 151K btu's. Oversized is always wrong. It's the mantra of this site, stated over and over.
I wouldn't hire either one.
Does a 'professional' really think you need 125 btu's per sq ft?

It's also a good time to upgrade the near boiler piping and components, and to add double filtration at the oil tank, OSV if a gravity job, and sleeved oil line (if you still have the original oil line under the concrete.

Tell me your town/zip and how many gallons you burned last year and I could give you a pretty good guess. I assume you have an indirect for your domestic hot water zone?

Some reasons I wouldn't do a heat loss for an oil fired boiler:
-I'm in a neighborhood of identical homes and did one on another house.
-In one neighborhood of row homes, heat losses are in the 11-14k range-the smallest boiler is 3x-4x too big.

I'd probably recommend an Energy Kinetics, or a Burnham MPO 84, which with a easy change in nozzle, pump pressure and baffles could easily be a 115, if 84k btu's isn't enough-which is probably too much anyways.
The smallest oil fired boilers don't go much below 60k btu's. Some of the cheaper mainstays offer 3 firing ranges.

JakeCK

Get a third or fourth quote. Don't even consider contractor number one. A heat loss must always be done to ensure proper sizing. And he doesn't even seem interested in entertaining the idea it might be over sized. That'll cost you big bucks. While Maine is a good bit further north then Northern Ohio a 1500sq ft house is a moderately sized house. Seriously doubt it needed 151k btuh in 92' even before insulation. 94k btuh is probably way too big too. My 1470sq ft colonial needs only 65k btuh with a design temp of 0f and it has no insulation in the walls and 6" in the attic with original wood windows with storms.

JakeCK

Also I have over 25 windows in my house.

JakeCK

> @STEVEusaPA said:
> Some reasons I wouldn't do a heat loss for an oil fired boiler:
> -I'm in a neighborhood of identical homes and did one on another house.
> -In one neighborhood of row homes, heat losses are in the 11-14k range-the smallest boiler is 3x-4x too big.

In low energy usage houses like that how do you guys prevent short cycling? Buffer tanks? It's annoying how big the smallest boilers are. I understand why the manufacturer is only responding to market demands but still.

STEVEusaPA

Buffer, if the customer will go for it (usually never because of the extra $$$-despite the full education), less zones. But almost always try to get mixing valves and/or aquastats with circulator hold off for boiler protection.
But it's always short-cycle city without a buffer.

Makes fall, and cleaning cold start, unprotected pin boilers such a joy.

As far as lowering firing rates, except for a condensing oil boiler, which no one in the US can seem to make work, you can only go so low with the firing rate to get a stable flame, and that flame will always have too many btu's.
Maybe lowest firing rate and larger water content in the boiler could be a start.

GroundUp

Absolutely forget about contractor A, and if Contractor B is who I think he is (out of Bangor?) I would run fast and far from that one too. Finding someone who will perform a heat loss analysis is going to be your best bet at this point, and hopefully they can shed some better light on what needs to be done. Odds are that even the Biasi is far too large for your needs at 78 BTU/ sq ft, a modern built home is typically 10-20 BTU/ sq ft via heat loss analysis and even a poorly insulated home seldom exceeds 40. If you're in a rural area, an educated installer is often very difficult to find but it may be worth paying someone who knows their trade to make the trip

jpod3311

@STEVEusaPA - Thank you for the thoughts! Yes, I have an indirect hot water zone. My zip is 04660, last winter we used 678.5 gallons of oil (five fill ups from 11/3/18 to 3/25/19). Bear in mind the current boiler is single pass from 1992.

@JakeCK - I had read a lot online about getting a heat loss done, but when I suggested it to the two companies they seemed to think it wasn't worth doing. I'm not sure if it's a product of me living in a fairly rural area (Mount Desert) or if they just didn't know how/didn't want to take the time. I appreciate the thoughts about the size of the boiler, and we're on the coast so that moderates our temperatures a bit compared to inland Maine.

@GroundUp - Actually, no, both guys are right on MDI. I'm definitely open to looking around for someone who does heat loss, I agree that looking at the numbers could be useful. I can try to call around some more, but you're right it might be tough to find someone!

Appreciate all the advice!
Joe

Intplm.

It is always, always worth doing a heat loss calculation.
You should indeed get a few more quotes.

STEVEusaPA

Assuming no other supplemental heat...
Closest city I have is Portland.
Under 40k btu's, using 7511 degree days and -1 Design Temperature.
I also put in 900 gallons as you probably used some before Nov, and after Mar.
Might be a little higher if you're getting constant wind.
But a full heat loss would be more accurate.

JakeCK

Another trick is if you track runtime of the boiler on a degree day you can get a pretty accurate picture of btu's used. If the boiler runs 20 minutes of an hour at design temp that is only a hair under 50k btuh as an example. And it has to be actual boiler run time not the tstats call for heat.

jpod3311

Okay, that's good to know. Sounds like the next step is getting the full heat loss to properly size the boiler.

Sincerely,
Joe

Jamie Hall

Actually, you can do your own heat loss, if only as a sanity check. Slant/Fin has a calculator on line which works pretty darn well and isn't that hard to figure out.

jpod3311

@Jamie Hall - Thank you for the suggestion! I just completed that as best I could. I did not take the attic or basement into my calculations, am I supposed to? Without those in the calculation, the heat loss is ~26k BTU/hr. Way less than either of the recommended ones!

STEVEusaPA

Yes you should. I actually came out with 36,642 on my little app, based on usage of 900 gallons but rounded it up to 40k. But I didn't subtract usage for DHW production.
But just using 678 gallons I came up with 27,604

jpod3311

Thanks Steve! Regardless of 26k or 40k or even 50k, I certainly don't need a 151k boiler it sounds like

STEVEusaPA

Unless you are willing to run some mains to the next 3 houses for district heat.

JakeCK

If you want good laugh play with the design temperature a bit. When I used the slant/fin app I wanted to see just how cold it could be with my oversized boiler... My 115k btu boiler wasn't fully utilized until -90f. Pretty much you could drop my uninsulated 90yr old house in antarctica and still heat. Of course this doesn't consider the EDR of the radiators but still interesting thought experiment.