Replacing Condensing Boiler

led

I need to replace a 200KBtu/hr Trianco condensing boiler.  I have researched a number of models and believe the Crown Bimini BWC-225 is my best bet -- any comment on that choice?

A second question -- the hot water feeds a 100 gallon storage tank that feeds 4 heating zones using hot water coils in air handlers and domestic hot water.  I have contemplated separating the heating water from the domestic by installing a domestic coil in a smaller tank.  Looking at the ratings of the domestic coils I can find I am concerned that they are not large enough to serve our needs -- 5 bathrooms, kitchen & laundry.  Any comment?

Thanks for your help.

Charlie from wmass

Are you using a buffer tank?

the domestic water is usually heated by way of an indirect water heater. Are you running a hotel or inn? If a 100 gallon indirect does not supply enough hot water with a 200 kbtu boiler powering it you are using a heck of a lot of water.

tim smith

What about condensing, ? Triangle or new Lochinvar wall mount

Is there a reason you are not looking at the condensing. Look at the new Lochinvar wall mount, 199,000 btu. Or Triangle 175 wall mount. Could be a good pick along with a 80 or 119 indirect.

led

Buffer Tank

The 100 gallon tank is a buffer tank which is kept at temperature by the boiler.  Water is drawn from that tank by a circulating pump to the four heating zones.  It is also the supply of domestic hot water driven by the well pump.  I have been concerned about cross-contamination of the systems and have taken some steps to minimize the likelihood of there being any.  We have had the system for 11 years with no problems.  Since we have to replace the boiler I am investigating whether I should make the mods to separate the heating system from the domestic.  Thanks for your comment.

led

Wall mounts

The Crown Bimini is a condensing boiler as is the Trianco.  I have looked at several wall mounted boilers including the ones you reference.  I considered installing two -- one for heating and one for domestic.  I am concerned with the capacity and ability of the units to keep up with the heating requirements.  In reading comments from people that have these units I find that there are more problems than good things said about them.  That may be because people generallly only report problems and not good experience but I am still leary of them.  They are also very costly.  Thanks for your comment.  

Charlie from wmass

You could pipe an indirect

directly off the boiler not going through the buffer tank.

tim smith

Re: Triangle

The TT prestige has been virtually bullet proof for us, install right and she runs. We have a bunch installed and have just been great.

Gordan

Ever run any on LP?

Have you seen any issues with ignition after the combustion parameters are properly tuned? Just can't get it to light...

Tim McElwain

Gordan, how is the LP piped to the unit?

Typically it makes for better light off if there is about a 10 foot run of pipe horizontally to the unit with a minimum pipe size of 3/4" pipe.

Gordan

From the boiler on out...

About 15" of 1/2 to the tee with the drip leg (horizontal), then about 5' vertical of 3/4", then horizontal 3/4", 1", 1 1/4" going all the way back. This is only a 60kBTU/hr appliance, so the gas connection on it is only 1/2". LP pressure was good during light-off - is there something else to consider?

Tim McElwain

Yes with LP on these

new Mod/Con units we have had problems when they first try to start up when there is not a sufficient manifold pipe on a horizontal run directly to the unit sized 3/4" or larger.

Gordan

So the main kind of acts like an equivalent of a starter capacitor?

How come it needs to be horizontal? From a lay perspective, it seems like having a drop to the appliance should help matters, so that the suction at the venturi is assisted by gravity, but I guess that's not right?

Ironman

Installing Two

If you're installing 2 boilers, why are you not considering piping them together in parallel and staging them? I'd recommend that you look at Buderus, Viessmen, ECR, Triangle Tube, Lochinvar Knight, etc. The all have multiple boiler options.



Also, running heating zones off of domestic is an open invitation for legionella.

Chris S

bimini boiler

We've installed the Bimini, and Triangle Tube.  Of course Crown is a great company with excellent product support, and parts availability.  Triangle as mentioned above is bulletproof.  The main difference in my mind is aluminum vs. stainless steel,  high head loss vs low head loss.  The concentic chimney system that crown has is very nice, and reasonably priced.  The roof termination is really sweet.  Traingle uses PVC, and a roof boot at the penetration.  I won't comment on your piping etc.  except to say that both of these boilers purr when they're tuned into a heating load, but then quickly step up to a DHW call.  Size it by the numbers, you won't be dissapointed.