Do I need a boiler with a coil if I buy an indirect water tank

Diverdown

I am in the process of buying a Burnham V83c and indirect water heater. The plumber recommends that I get a coil in the boiler. I thought I didn't need one. Are there any reasons to get a boiler with a coil when I am also getting an indirect?

Robert O'Brien

No reason

If you have an indirect,no reason to buy a V8 at all,it's a single pass pin boiler. If you like Burnham,go with an MPO,it's a triple pass and don't forget the reset control!

Mac_R

NO!

There is no reason to have a coil in the boiler when you are using an indirect water heater.  All that coil will do is use up your fuel.  It will also make you use a high mas boiler in place of a low ore med mass boiler.  The less water in the boiler the better.  Sounds like the person you are using has no idea of what they are doing.  Look into the MPO IQ if you want to go Burnham.  I recommend Buderus.  Some people here like the system 2,000.  Do your self a good thing and look into another contractor and system.  Your savings will much larger with a better system.

Steamhead

I agree

the MPO is a much better boiler than the V8.... more efficient and easier to service. It might cost a bit more but the difference is worth it.

Ron Jr._3

You can use a coil boiler

with an indirect . You can control it just like a triple pass too . If someone has real world fuel use comparisons between a new properly sized pinner and triple pass ( same hot water maker and controls ) I'd love to see 'em !



The only reason you'd want to hook in the coil if you have an indirect is for backup . In case the indirect crapped out you can bide some time to research your options . We've installed a few in the past as an option .

Paul48

I Disagree

The MPO is wrong for this application. You'll have to do everything in your power to prevent it from reaching its designed efficiency, condensing and rotting the (cast-iron) heat exchanger in short order.The only other way to save, is to make the boiler a cold-fire boiler, which probably would take a third to a half off its life-span. IMHO

Charlie from wmass

Is this for steam?

or hot water? The coil may be used as a heat exchange if this is steam. If it is steam then the Burnham Megasteam is a better choice.

Robert O'Brien

Paul

How much experience do you have with cold start triple pass oil boilers?  Works just fine on baseboard,fintube and CI systems,may need P/S or a bypass loop on a large CI system but that's about it

Paul48

Robert

I'm not a pro, but as far as I know, all cast iron and steel boilers should have some sort of boiler protection from condensing flue gases.I've seen the results and early demise of cold-fire boilers. I am a big fan of cast iron boilers, I just don't think it is the proper material for boilers with efficiencies in the high 80's.

meplumber

You are way off base Paul.

Cast Iron has its place.  More so than low mass problematic mod/cons.  Your claims are not supported.  The MPO is an excellent choice in this application.



As to Ron's post about real world numbers, try saving 200 gallons over a heat season by switching from a single pass, top flue pinner (New Yorker Cast Iron 3 section with tankless coil) to a Buderus G115/21 with an indirect.  One of my customers from 2 years ago did.  This is in Eastern Maine with a -10 design temp.  Will that happen every time?  I don't know.  But it did here.

Paul48

Buderus

reallized they could not use regular cast iron for their 3 pass boilers. They use a special patented, corrosion-resistant cast iron.

meplumber

It isn't that special.

I have been to their N.H. facility and to their foundry in Germany.  It has an additive to assist with expansion and contraction, but so do all the castings coming out of Bally, PA.  Corrosion has never been a problem with cast iron.  I work on boilers that are 70+ years old and still ticking.  The cast iron isn't the problem if yours failed.  It was the installer.