New Boiler config options help

[xdanimalx]

Hi all,

I have a 1960's American Standard 180 btu boiler with a built-in coil for domestic water. The boiler needs to be replaced and I'm just looking for a general "thumbs-up" that the option that has been presented to me by the plumber makes sense or if there are any potential gotchas here. Here's the beef:

3 level home w/2400 square feet, old casement windows
replace w/ Laars Mini Therm copper boiler 160 btu, 2 stage
build new side arm w/50 gallon tank for domestic

My questions are:
Is it generally better to build a side-arm or are there options / benefits for having a tankless boiler system? Do they make them still?
Is the boiler presented a good option or are there other mfg's I should look at - how about an iron boiler?

Thanks in advance for any education & insight!!!

[meplumber]

I prefer to purchase an indirect dhw tank.

180,000 btu's is huge for 2400 sq ft. Are you in Fairbaks, Alaska?

Did the guy do a heat loss calculation? There are far better boiler options out there.

[xdanimalx]

The 180,000 is old to be replaced with 160,000. The calc was done if that was the calc that includes the linear fr. of the radiant heaters.

indirect dhw tank....That's not the same as a "side-arm" tank?

Also what other boilers would you recommend?

[BaldLoonie]

You better find you a HEATING PROFESSIONAL not a plumber. The proper way to size a hot water boiler is to the do a heat loss calculation to see what heat the house loses. Sizing to radiation is for steam only.

An indirect tank is for water heating. Side arm sounds like something from the good old days.

Cast iron boilers get upwards of 85% with gas and no special controls. Then there a big price jump up to the 90+ condensing boilers.

[ascj]

You better find you a HEATING PROFESSIONAL not a plumber. The proper way to size a hot water boiler is to the do a heat loss calculation to see what heat the house loses. Sizing to radiation is for steam only.

An indirect tank is for water heating. Side arm sounds like something from the good old days.

Cast iron boilers get upwards of 85% with gas and no special controls. Then there a big price jump up to the 90+ condensing boilers.

Also may I add....an indirect water heat load shouldn't be added to the required heat load of the house. That's what priority is for.

[xdanimalx]

Then may I ask - without specifics that would be required from the calcs - what would be the most common arrangement for this scenario?