Security Seal Facebook Twitter GooglePlus Pinterest Newsletter Sign-up
The Wall


Joined on January 18, 2012

Last Post on July 30, 2014

Contact User

Recent Posts

1 2 »

new info.

@ July 30, 2014 4:09 AM in Slant-Fin Monitron 2 problem

not sure if this helps, but homeowner informs me that the alarm usually starts up in the morning, when they first turn the heat on for the day. non-programmable stats. Last week, I asked him to try turning on a different zone each morning, leaving the others off (4 in total).
what we found is that the system alarms no matter which zone calls first. I may come back to take a closer look at the field wiring. I can't see why a thermostat circuit would trigger a "return sensor-open circuit" type fault code.

one other thing to mention

@ July 26, 2014 11:14 AM in Slant-Fin Monitron 2 problem

The digital controller has 8 operational modes. Mode 4 is parallel piping (trunk & branch, supply/return manifold with zone valves), which is what this boiler is operating in. It's worth noting that this mode doesn't utilize the inlet temp sensor, just the supply sensor and built-in ODR. Both of these sensors check out OK too.

Slant-Fin Monitron 2 problem

@ July 26, 2014 11:11 AM in Slant-Fin Monitron 2 problem

One of my customers has a Slant Fin Monitron 2, installed last year by a different contractor, which has been alarming on a fault code. The code indicates Inlet temp sensor - open circuit.
Naturally I first checked for correct field wiring of the sensor into the board, which looked OK, then tested the inlet sensor by measuring ohms, which checked out fine. I called Slant Fin's tech support line, they said if the sensor checks out OK, it must be the digital controller (model em-10). They sent me a new digital controller and I replaced it. I changed some of the factory settings to cancel the pump post-purge (because they don't have a diff. pressure bypass installed, and I noticed the circulator was deadheading).
Next week the customer called and informed me that the alarm was still going off. Having tested all the usual suspects, I called their tech support line again. The guy was stumped, went to discuss it with their engineering department, and got back to me. The engineering department didn't have an explanation either, but they suggested a complete swap-out of the electronic components. I replaced the PC board, digital controller I mentioned earlier, and the wiring harness that connects the two.
I contact the customer a couple weeks later to see how things are going....The alarm is still going off, the fault is still Inlet temp sensor - open circuit.
Anyone have any ideas on what to do next? This is my first issue with a Slant Fin....usually their stuff is pretty reliable. Not sure what to do next.

Thanks Eugene!

@ May 8, 2014 10:38 AM in figuring CFM required


no AC

@ May 5, 2014 8:11 AM in figuring CFM required

The system in question is a forced air, oil-fired furnace. Definetly no AC plans for the future, main system is designed for heating only.

have the btu

@ May 5, 2014 6:04 AM in figuring CFM required

Hi  Techman,
I already have the btu of the room. The home is already heated by a furnace, but I need to install a duct into a currently unheated room. Want to make sure it is sized properly. I have all the parameters except for the temp differential typically used in this formula.

figuring CFM required

@ May 4, 2014 1:57 PM in figuring CFM required

Hi guys, I am attempting to figure out the CFM required to heat a 300 sq ft room using the formula CFM=btu / (1.08 x delta T)
What is the typical delta T used in this calculation?
Thanks !


@ February 6, 2014 9:14 PM in Singing diverter-tee system

The burner is oil-fired, Mark. It is fed by a copper line, coiled to absorb vibration. It is louder upstairs than in the boiler room, so I don't see it being a burner issue.
Your description was right on the money though, it is very much a "harmonic whistle".

I've visited the house

@ February 6, 2014 4:52 AM in Singing diverter-tee system

I was there to investigate the sound, but it did not appear while I was onsite!
That is the most frustrating part. System seems to be operating properly. There are no vibrations that I could see/hear. Circulator is operating properly. Customer says that it happens while the system is running

file did not attatch

@ February 4, 2014 10:06 PM in Singing diverter-tee system

Looks like the file did not attach.
The sound in question is like a faint ringing. High pitched but not a squeal, more like a fog horn but high pitched. It is "constant and consistent, not intermittent" according to the customer, and is heard when the system is running.

Singing diverter-tee system

@ February 4, 2014 10:01 PM in Singing diverter-tee system

A customer sent me this audio file. Her heating system has been making a ringing sound when in operation. I went to investigate the sound but it did not show itself while I was there, hence the recording.
System in question is a diverter-tee/monoflow system, 1.25" main, Grundfos 15-42 circulator on return, steel expansion tank. Single zone with cast-iron radiation above and below the main. All radiators are bled and somewhat in balance.
On the recording, the noise can be heard faintly at 9 seconds and again at 15 and 28 seconds. At 19 seconds the burner can be heard.
I haven't heard a sound like this before, anyone have any ideas?

boiler replacement: question for one-man shops

@ January 3, 2014 6:34 AM in boiler replacement: question for one-man shops

Happy new year folks!
Looking for some advice for fellow one-man shops here.
I have a couple of boiler replacement quotes coming up. One boiler to be replaced is a sectional cast-iron (five sections), the other is steel but still considerably large. As I work alone, I'm not sure how to move the old boilers out of the basement. In previous quotes I have not priced removal. Some owners wanted to keep the old boiler, some wanted a dual-energy setup, etc. But I have lost some possibly good jobs because I did not have the means to remove the old boiler.
I'd like to have a plan in mind to remove the old, heavy boiler safely. just wondering how some of you guys dealt with the situation. Thanks!

hello RJ

@ September 25, 2013 9:04 PM in ac system design help

I'm doing an air system design course hopefully this winter.
Since I wrote the original post, I have acquired a ductulator and learned some useful formulas, which has opened my eyes quite a bit.
Regarding the Trane AC manual - is it available directly from Trane? I don't see it on their website.

looks like

@ September 25, 2013 9:02 PM in ac system design help

Looks like it's going to be mini-splits after all. Owner doesn't want to compromise celing height. Thanks!

ac system design help

@ September 17, 2013 5:01 AM in ac system design help

hey guys,
I have a potential customer who wants zoned AC in a small office space using a multi-split heat pump. Did a load calculation & found that each office requires 5-600 BTUh of cooling, obviously mini splits are a bad idea (smallest indoor unit I can find cools to 9000 BTUh.). So I am looking at other ideas.
The entire office suite is only 1250 sq ft and could in theory be cooled by one mini split if it were open concept, but each office/room requires its own zone.
I've been thinking about presenting the customer with other options, such as zoned ducted AC with a variable-speed air handler and motorized zone-valve style dampers. However, I'm not up on AC duct sizing. Don't want to undersize.
Is there a sizing rule-of-thumb for AC ducts, something I can do to get a basic calculation of sizing for the purposes of working up an estimate?
I am doing a duct design course this winter but this job came up too early!
Thanks guys! If anyone has other ideas on how to configure this system, I'd love to hear these also

Paul, fear not

@ February 28, 2013 4:51 PM in re-piping an old rad system...

She will get the respect she deserves.
Gutted, yes, but restored to her former glory. The GC on this job is some sort of "heritage home" specialist. First time working for him but apparently this is what he does. I looked at 2 other jobs with him today, similar heating situation. Won the bid on this one BTW, and looks like there might be more in the future.
Thanks everyone for your help. I love the Wall.


@ February 28, 2013 9:42 AM in re-piping an old rad system...

natural gas maybe in about 20 years. Electric baseboard heat is king here. A large portion of my work is converting systems from oil-fired to electric boilers.

The radiant manifold has me thinking.

@ February 28, 2013 9:41 AM in re-piping an old rad system...

It seems to me, in theory at least, that with a home-run loop from a radiant manifold to each radiator, it could be possible to zone room-by-room with an actuator snapped onto the head of each balancing valve. Once the flow is properly balanced to each rad, install the actuator and set up the controls.Or, at least pre-wire it for future room-by-room zoning as an upsell.
I'm aware of course that a TRV would do the same job a lot easier fom an installation perspective. Just thinking "out loud".
Ivanator, your idea sounds exactly like what I am trying to accomplish. You asked why zone room-by-room. It has a lot to do with culture and construction around where I live
We are experiencing the 10th year of a housing boom/suburban sprawl in which every new home is a turn-key job with electric baseboard heat. Hot water heating is perceived, sadly, as either something from a bygone era (older Victorian homes like these, with poorly-operating heating systems) or very expensive/only suitable for large custom homes (in-floor jobs).
In cases like this job, where a major renovation is taking place, I'm bidding against an electrical contractor who wants to put in electric heat. To win the job I have to offer the same features of electric heat, the most common of which is room-by-room zoning. I'm quoting for people in their 40's who grew up with oil-fired hot water heat, single zone, badly-running system, and is swayed to electric for that reason. I have to give them all the features of electric. A common sentiment is expressed "I like those big old cast iron rads, but oil heat (sic) is always so uneven, the thermostat is downstairs and upstairs gets too hot etc etc"

Thank you Chris

@ February 28, 2013 9:21 AM in re-piping an old rad system...

much appreciated


@ February 26, 2013 8:19 PM in re-piping an old rad system...

...everyone for your replies.
I've looked through a few threads on this topic (there are a few here) and it seems like a few have used radiant manifolds to successfully zone radiators. I'm pretty sure I'm going with this idea, using one manifold per zone. More than likely going to zone with circulators, so  one circulator per manifold. As for the sizing of the home-run circuits off each rad, I'll be doing a heat loss calc soon...waiting on the owner to decide what type of insulation & windows he will be putting in.
Steamhead, to answer your question TRVs are an excellent idea, but not for this particular system. The original installer tried to do a monoflo system using regular tees,  and thus very out of balance. Subsequent homeowners have put up with it because "those rooms are cold, that's the way the heat is". This house will be strip-to-the-studs renovated, so I am re-piping it entirely.
Chris- I like your suggestion but not familiar with systems using a 4-way mixing valve. How would one arrange the near-boiler piping on this type of system.
Eric - Love the drop-ear idea. Will be using it. Neatness definetly counts.


@ February 26, 2013 10:51 AM in favorite zone valve?

I'm partial to the Honeywell zv myself...readily available, easy to swap out when needed, seems to last a good long time. I've worked on systems with honeywell ZVs that must have been 40 years old, still working fine.
I wouldn't mind trying the Taco sentry one of these days though. I like most of Taco's stuff, just haven't given their zone valve a try yet.


@ February 26, 2013 10:40 AM in help with measuring airflow

a vane anemometer would be better for this particular situation?
I use the magnehelic for balancing procedures, and the anemometer for measuring at terminals such as diffusers, grilles etc. I don't use the pitot tube very much
1 2 »