Boiler choices and sizing.

Oldranch

Boiler choices

House is 1950's build, open floor plan. Half brick, low pitch roof with no attic. 2/3rds crawl space and 1/3 slab. All windows replaced 2016 – double pane low E, high quality vinyl. New roof (2017) w/1-1/2” insulation board (this really tightened up the house).

132' of BaseRay cast iron base board radiators. These seem smaller than the 9A model, only about 6-3/4” tall. One BaseRay slenderized radiator 5 tube, 1-3/4”ctc, 25” tall with 14 sections in kitchen and one BaseRay slenderized radiator 6 tube, 1-3/4”ctc, 32 tall with 6 sections in the utility room.

Currently have a 25-some year old Lochinvar RBN 135. I don't know what the Lochinvar replaced but I remember it had to broken up into pieces (gigantic cast iron) to get it out of the utility room.

My own boiler sizing by the radiation method says I need about 55.5MBH.
The Slantfin contractor by manual J method says I need 53982MBH.
The Weil-Mclain contractor says by manual J (different software, I asked) that I need 57556.

I believe both of them. Pricing is similar for both.

Which boiler will be the most reliable for the next 10 years?

Gas fired, chimney vented SlantFin Sentry S-90?
Or
Gas fired, chimney vented Weil-Mclain Cga4?

NY_Rob

Why not consider a mod-con like the HTP UFT-80W?

It would be a great match with all the cast iron radiation you have. You'd probably condense most of the year at 90% + efficiency due to all the mass in your system.

Oldranch

I guess I'm not too keen on cutting holes in my roof for the air and exhaust pipes. Also, it seems like you get a longer warranty with a conventional cast iron boiler.

NY_Rob

10 yr warranty on the HTP UFT boiler.

Lochinvar also offers an excellent series of mod-con boilers with additional feature over the bare bones HTP UFT series.

Most side vent their mod-cons with inexpensive PVC, but you can get a chimney kit to exhaust through your existing chimney if you'd like. You can also use indoors air vs. outdoor air for intake/combustion if you don't want a 2" or 3" hole in your wall.

Did your contractor mention that your present chimney would need a ($1k) liner if you replace your current boiler? Many areas require that nowadays on boiler replacements.

Oldranch

You know what, neither contractor mentioned or priced a chimney liner. What is the reason for lining it if the current boiler is exhausting properly out of the chimney?

I think through the wall is a no-go because the boiler and water heater are in just about the center of the house. Nearly flat roof w/no attic access.

Steamhead

I agree, in your situation chimney vent is the way to go. Either of those boilers should be fine. If that were my job, I'd also look at the Burnham 304- it has a nicer control system.

If there's any way to add insulation under the roof, you could probably get away with the next size smaller boiler.

EBEBRATT-Ed

@Oldranch
I like the Weil Mclain but that's just me. You could use the chimney for a chase for the mod con flue and intake if you go that route.

1950s the flue probably has a clay liner. If it's an interior chimney in good condition you may not need a liner unless the chimney is oversized for the new boiler (which it could be oversized) newer equipment has higher efficiency and runs with a lower flue temp which may require a liner to prevent flue gas condensation. You contractor should know this. If not, find a certified chimney sweep to do the liner after the boiler size is picked

newagedawn

peerless makes a nice gas boiler

Tinman

Buderus cast iron is really good. I'm also a big fan of Burnham and Peerless.

Oldranch

1950s the flue probably has a clay liner. If it's an interior chimney in good condition you may not need a liner

Yes the chimney is interior and has orange tile sections that are all intact. The brick portion on the roof was tuck pointed and had a new concrete cap about 6-7 years ago.

So I gather from everyone's comments that most of the well known boiler companies put out a decent product.

As to sizing, can anyone comment on the models I've gotten pricing on so far? OK or maybe too big.

HVACNUT

Look into the EK Frontier and Resolute. The Resolute is 90+% non condensing. Sleeve a polypropylene liner through the existing chimney. It does require outside combustion air so maybe you can cut out a bay space for 2" PVC.
The Frontier can use your existing chimney, but if it was me, I'd install a liner.

delta T

Out of the two you proposed I would choose the WM. Really it comes down to the contractor, and what kind of installation you are getting. You actually got two different contractors to do a real heat loss! Congrats, it is all to rare these days!

Oldranch

Still getting estimates and many different choices of boiler. How about opinions on a Carrier BWB cast iron boiler as a replacement?

HVACNUT

I believe for boilers, Carrier is a rebadged Dunkirk.
IMO, there's better choices.

Steamhead

HVACNUT said:

I believe for boilers, Carrier is a rebadged Dunkirk.

IMO, there's better choices.

That is correct.

Oldranch

The contractor said it is made by Utica. It is sold with a 20Y heat exchanger warranty, a 10Y parts and I'll get a 5Y labor from the contractor. This warranty package seems pretty good compared to most others. Oddly enough, another company gave an estimate for a Bryant boiler and it is the exact same model number as the Carrier. They even look nearly identical, the the Bryant quote was considerably higher though.

The guy who quoted the Carrier also installs Weil-McClain and Burnham but said his company is a stocking distributor of the Carrier stuff so he tends to favor that. The W-M and Burnham would add 5-7% to the job total. I really like the W-M but I also want this contractor to do the job and be comfortable with what they are putting in. So if the Carrier is a really bad choice I'll go W-M and hope for the best.

Oldranch

Went with the Carrier - best warranty of all quotes.
What about my NBP? It seems like we are pumping away from the EX tank but the air eliminator?

Should it be on the hot side?
When the tech fired it up, all my baseboards got warm within 10 minutes and super quiet so I feel OK, but just checking with you all.

HVACNUT

Umm... so either the circ is pumping north, but its on the RETURN, or its pumping south and your air eliminator is on the return which isn't right because you want those bubbles busted before they get to the emitters.
Not sure of the effect on the PONC.
Either way, call him back. Good thing he gave you 5 years P&L. I think you might need it.

ScottSecor

Looks like relief valve is upside down. Handle and rating tag should be pointed at the sky. We prefer to locate the air eliminators where the boiler water is the warmest (supply).

Steamhead

How about a view from the front, so we can see how the circulator is oriented?

Oldranch

The directional arrow on the pump points at the floor.

Good thing he gave you 5 years P&L. I think you might need it.
HVACNUT, will you elaborate on your comment?

Oldranch

Here it is.

EBEBRATT-Ed

he certainly did not pipe it right. he needs to turn the relief valve right side up.....doesn't meet code in any area.

the rest of the piping could have been done better. it would have been the same amount of work to do it right............

if the system has low resistance it will work as is

HVACNUT

> @Oldranch said:
> The directional arrow on the pump points at the floor.
>
> Good thing he gave you 5 years P&L. I think you might need it.
> HVACNUT, will you elaborate on your comment?

Well sometimes I try to find humor in things to lighten any misfortune. There's truth in laughter.
The piping seems a little atypical, but it will work, however no experienced heating contractor that I know of would pipe a boiler like that.
For forever and a day, the rule has been pumping away.
And unless it's in another room, I don't even see a purge station. Slab mono flo?
And the pressure relief valve? Why?

I understand you spent a lot of money for your system, that's why I recommend you take FULL advantage of the P&L and have them do it right.
Who knows, there might even be a piping diagram in the I&O manual.

I have to chuckle when I see things like that, (otherwise I'd go insane) but I'm not trying to slight you personally.

Oldranch

Hi Guys, two things;

1. How do I tactfully request a re-piping job from the contractor? Do I tell them that HVACNUT on the Heating Help forum says it wrong? What do you all think I can expect in response? What would your response be if you had done this work?

2. What exactly are the ramifications of leaving things as they are? Will the boiler's lifespan be shortened? Not making excuses for anything but the I&O states that, Circulators in following illustrations are mounted on system supply side, mounting on system return side is also acceptable practice. With that instruction in mind, the only other pumping problem seen is the placement of the expansion tank, right?

Thanks to all for your time and knowledge.

HVACNUT

> @Oldranch said:
> Hi Guys, two things;
>
> 1. How do I tactfully request a re-piping job from the contractor? Do I tell them that HVACNUT on the Heating Help forum says it wrong? What do you all think I can expect in response? What would your response be if you had done this work?
>
> 2. What exactly are the ramifications of leaving things as they are? Will the boiler's lifespan be shortened? Not making excuses for anything but the I&O states that, Circulators in following illustrations are mounted on system supply side, mounting on system return side is also acceptable practice. With that instruction in mind, the only other pumping problem seen is the placement of the expansion tank, right?
>
> Thanks to all for your time and knowledge.

Like I wrote the the earlier post, it will work the way its piped. There might be some air issues down the road.

The concern is the relief valve and how the loop can be purged.

DZoro

Turn the relief valve upright, yes it will work. There is 2 boiler drains not the best locations but you can flush/fill with them. Pretty basic work, seen much worse, but should to you good.

Oldranch

Any input on my first question?

hot_rod

Hydronics is a somewhat forgiving technology and even systems piped less that perfect will work. I doubt the installer will agree to completely repipe it.

It comes down to how much repiping you want to do. At the least the installer needs to correct the relief valve mounting, the instructions are probably clear on acceptable mounting positions.

And move the expansion tank connection, regardless of where the circulator ends up, the expansion tank connection needs to be on the suction side somewhere.