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Joined on November 26, 2011

Last Post on July 23, 2014

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trenchless replacement

@ March 21, 2013 11:04 AM in Water service freezing

would be my first choice.  Do you have anyone there with the equipment?  If the line thaws, you might even be able to pull a replacement without bursting.  Surely something smaller (possibly a 1-1/4") would serve the needs of a residence?

You could pull either an electric heat trace or a pair of hot water heating lines at the same time.

just give us

@ March 21, 2013 10:59 AM in Just Don't Get Modcon Boiler Pump Charts!

a few different 00 ends and I'll be happy.  The 0010 is almost a perfect match for 399k fire-tube designs.


@ March 21, 2013 10:52 AM in Adding a secondary pump to my radiant heating system

The 0013 does not have a flat pump curve.  A 0010 does, and makes a pretty good replacement for a Series 100 in most applications.

80 to 90 KBTU

@ March 21, 2013 10:45 AM in Do I really need a Navien CH-240?

is quite a large heating load.  The 20k minimum firing rate of the the CH-240 ASME makes a relatively good match, but what kind of efficiency does the unit achieve at low firing rates?  I'm not familiar enough with the differences between AFUE and CAFUE to infer anything from those.

Bumble Bee

@ March 21, 2013 12:25 AM in Just Don't Get Modcon Boiler Pump Charts!

would be the perfect boiler pump -- if Taco would just make it in other sizes.

I size ~5F below boiler ∆T alarm level, then find the nearest match -- ignoring brand or style.  This approach has led me to selections as diverse as an ecocirc e3 and an Armstrong S25.  No disappointments so far.

40 percent

@ March 21, 2013 12:14 AM in Antique Cast Iron Boiler Information Needed

is not unreasonable given the age of the beast.  ODR will provide increased comfort as well.  What did you factor for annual fuel cost increases?

you will make money every time...

@ March 21, 2013 12:09 AM in If you were designing a heating system for dream house/dream shop, what would it be and what design tweaks would you take to maximize efficiency?

in the right climate, with a properly sized and installed system.

But you know that...

Wish I were closer

@ March 21, 2013 12:03 AM in Viessmann ECDS cast-iron boilers 4 sale

Those are some of the best built conventional boilers I know of.  Ought to be a great deal for somebody...

system re-work

@ March 20, 2013 11:39 PM in Radiant heat back up

First you want to understand you tank capacity and architecture.  You may be able to extract solar input from the boiler coil, but valving and controls could get a bit tricky.  Thermal capacity of the tank will determine how many panels it can support, but I'd worry about DHW temp dropping below safe levels.


@ March 20, 2013 9:40 AM in Viessmann ECDS cast-iron boilers 4 sale

are they located?


This is exactly why

@ March 20, 2013 9:37 AM in Just Don't Get Modcon Boiler Pump Charts!

I don't like boilers with factory-provided circulators.  Say hi to Rick for me.

nice to see another

@ March 19, 2013 11:58 PM in Sprinter look a like from Fiat

3-4 litre DIesel option available here in the US.  We've been deprived for too long...

sure, that will work...

@ March 19, 2013 8:42 PM in Just Don't Get Modcon Boiler Pump Charts!

but it won't come close to maximizing boiler efficiency.

iPad presentations

@ March 19, 2013 8:41 PM in Curious!

Have you tried Keynote for IOS?

Just looked

@ March 19, 2013 7:19 PM in Need some info.

and it's an add-in according to

I'd call HeatLink and see if they could assist with the install.


@ March 19, 2013 7:01 PM in Need some info.

will not open .exe files.  Try double-clicking on setup.exe and see what that does.

You really need

@ March 19, 2013 6:58 PM in Delta T issue

a full system analysis.  This starts with a room-by-room heat loss calculation, a room-by-room radiation survey, and a table of all the distribution piping.  From this, you will determine what water temperatures and flows will be required at design conditions.  Then each segment of pipe is evaluated to see if it will carry what is required of it.  After all that is done, the appropriate system circulator is chosen (possibly more than one.)

If this process led you to an undersized manifold feeder, the best answer would be to increase the size of the pipe.  Barring that, you might consider using a dedicated circulator for that manifold, since it differed from the other piping enough to warrant a different pump curve.  The point is that you need to deconstruct the original design and then reconstruct it properly before you start buying parts.

heat flux

@ March 19, 2013 6:37 PM in Indirect DHW tank Delta T? will give you the engineering school version.  Across a heat exchanger, heat flow is proportional to surface area, conductivity of the HX material, and the difference in temperature.  The first two don't change appreciably, so it really comes down to the difference in temperatures.  As ∆T increases, more heat will move during each unit of time.  The hotter the average boiler water temperature and the colder the incoming water, the faster heat will move into the DHW.  As the DHW gets close to the setpoint, the rate of heat transfer slows down.  A smart boiler control will "see" this coming using a thermistor in the DHW tank, and stop before the tank overshoots too much.  Keeping the tank at 140F prevents legionella growth but requires a thermostatic mixing valve at the tank output to protect occupants from scald injury.  Raising the tank temp to 150F or 160F has the effect of making the tank "larger" from a thermal capacity standpoint.  Speeding up or slowing down the DHW circulator without also changing the DHW target temp will simply move the average boiler water temp up or down a bit.  This will affect DHW recovery rate, but not anywhere near as much as changing the tank setpoint, boiler water target temp, undershoot and overshoot temps, etc.


@ March 19, 2013 9:47 AM in Delta T issue

may not be the best standard for determining complex flow mathematics.  Nothing personal, but you really need to step back and look at the whole system design.  Where are these manifolds located?  Is there any way to either increase or supplement a supply/return line or lines?   I think we mentioned splitting manifolds earlier.

deltas T

@ March 19, 2013 9:42 AM in Indirect DHW tank Delta T?

There are two different numbers at work here.  The first, which you have described, is the difference between water leaving and returning to the boiler.  The second, which the manufacturer quotes as 65F, is the difference between the incoming cold domestic water and the desired hot water temp or tank limit.  The greater this difference, the faster heat will transfer from the boiler to the DHW, but the water still has to get up to the target temp, which will take longer with colder incoming water, assuming the boiler water stays at a fixed temperature (which of course it doesn't.)  The nominal boiler water temperature is an average of supply and return temps.  If the circulator runs slower, this average will drop, but that can be remedied by increasing the supply temp (assuming the boiler can still keep up.)

Does your indirect have a mixing valve at its output?  Do you have hard water?  How long has it been since the boiler was inspected and cleaned?   Assuming you want more hot water, these are the areas I'd be looking at first.

the ultimate goal

@ March 18, 2013 10:04 PM in Adding a secondary pump to my radiant heating system

is to make you system work properly.  If we don't understand how it was designed and installed, we stand precious little chance of improving it.

Photos of the boiler and associated piping, valves, etc. would help.

The Series 100 is a wonderful high flow low head pump.  I've never used one on floor loops so I'd really like to understand the rest of the design.


@ March 18, 2013 9:24 PM in MONO FLOW SYSTEM NOISE

"same btu rating" won't ensure the correct replacement is installed.  You can pretty much count on the opposite.

Outdoor reset control of system water temp along with constant circulation on those loops should remedy your expansion issue, but we need to take a look at the rest of the design before we propose changing anything.
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