Pump paranoia

January 30th, 2015
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I am still obsessing about the boiler shut down. And now, after I have explained the heating system setup, I can share the development of my pump paranoia without making it too abstract.

The error message (“174 Lockout safety relay feedback incorrect”) on our Trinity LX 150 indicated that something in the pre-ignition testing went wrong.

I cleaned the flame sensor rod and electrical spark ignition – both standard maintenance items. But neither of them showed much oxidation and both were pretty clean to begin with. The condensate drain, which could also be part of the problem, was clean and free flowing.

In search for a rational explanation, my mind wandered over to the pumps. As shown in the previous post I have three pumps:

  • The domestic hot water pump


  • The boiler pump


  • The main pump (system pump) for the hydronic heating system


In addition to that I have three pumps, each feeding one of the heating zones:

  1. The basement
  2. The first floor
  3. The second floor

I was under the impression that the main pump (system pump) for the hydronic heating wasn’t running and as such may have contributed to the boiler lockout.

Maybe I had been playing a little too much with the touch screen on the boiler, which showed the status of the three main pumps. But whenever the boiler was running, the pump status on the touch screen didn’t correspond to which pump was actually active.

With a little more research, I discovered that I can run a diagnostic test on the pumps.

Only one out of three pumps passed the test! Time for panic?

Well, it turned out I was barking up the wrong tree – and that I have an installer, Mariusz, that puts up with my nerdiness.

Related posts:

Mechanical system explained

Breaking a cold sweat

Utility room installation

The heat is on!

Wrestling the unruly…

Connecting the unruly…

Baseboard radiators delivery

Radiator connection preps

Radiator installation

Peak stress

Radiator déjà vu

Radiator start up


Mechanical system explained

January 27th, 2015
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While writing the last post about our boiler going into lockout mode, I realized that after all these years I never fully explained our mechanical system.

I have posted a time lapse showing the utility room setup and described the PEX and radiator installation, including the difficulties we encountered along the way, but I have yet to show the components of the mechanical system in the utility room and how they work together.


The diagram above does exactly that, except most of us will have some level of difficulty deciphering it. Let me try to put it into a format that is easier to follow, starting with a list of the main components (I won’t list all to keep it reasonably simple):

Boiler (Trinity LX 150)


This pieces of equipment is basically heating the water for the hydronic heating system (radiators and radiant floor slab) as well as indirectly heating the domestic hot water (DHW).

Boiler pump


This pump is moving the water through the boiler into the buffer tank while the boiler is firing.

80 gallon buffer tank (insulated)


This tank is feeding the hydronic heating and also (indirectly) heating the domestic hot water system. The tank temperature is set to 140 degrees Fahrenheit.

Due to our low energy load on the space heating and DHW side, we run the risk of short cycling the boiler. The buffer tank prevents that by providing the initial thermal energy. In that process, the temperature in the tank drops and is elevated again through hot water supplied by the boiler. But at this point the energy load is large enough for the boiler to run efficiently and without short cycling.

Main manifold


This is a three zone manifold supplying hot water to (1) the radiant floor slab in the basement, (2) the radiators on the first floor, and (3) the radiators on the second floor.

Zone pumps

In the manifold are three zone pumps, supplying hot water to each zone once the thermostat of that zone turns on.

Mixing valves

Also in the manifold are mixing valves for each zone. The mixing valves reduces the temperature from 140 degrees Fahrenheit to the supply temperature of 120 degrees Fahrenheit.

System pump


Whereas the zone pumps push the hot water into the hydronic heating system, the system pump sits right under the manifold and pushes the water from the system back into the buffer tank. This pump is activated whenever there is a heating signal from any of the three zones.

120 gallon domestic hot water storage tank (insulated)


This tank supplies domestic hot water to the kitchens and bathrooms throughout the building. The tank is heated with hot water from the buffer tank that flows through a double walled heat exchanger. This way, the non-potable water from the hydronic heating system does not mix with the potable DHW. Because the tank has no gas or electrical powered heating element, it is also referred to as an indirect water heater.

DHW mixing valve

The temperature in the DHW tank can also get up to 140 degrees Fahrenheit, which is dangerously hot. To prevent scalding, the temperature is mixed down to 120 degrees Fahrenheit, which is also the supply temperature to the various faucets and showers.

DHW pump


This pump is feeding the water from the buffer tank through the heat exchanger in the DHW tank whenever there is sufficient hot water demand.

To make things a little easier to follow, I put a simplified diagram together that is animated and shows how the system is working. I hope this will do the trick.

Related posts:

Utility room installation

The heat is on

Wrestling the unruly…

Connecting the unruly…

Baseboard radiators delivery

Radiator connection preps

Radiator installation

Peak stress

Radiator déjà vu

Radiator start up


Breaking a cold sweat!

January 18th, 2015
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A week and a half ago, during the nice, crisp cold snap, I woke up in the morning and felt like something wasn’t right. Still half asleep, I touched the bedroom radiator, which was barely warm. I found my way from room to room touching radiators – all barely warm.

Some kind of subconscious decision making process led me to the thermostat, which showed that the heat was on.

That woke me right up, plus I broke a cold sweat! Something wrong with the heating system in this weather is bad news – well insulated building or not. I skipped the first cup of coffee and instead found my way into the utility room.

I heard a couple of pumps humming, but the boiler (Trinity LX 150) was dead silent. The temperature gauge at the buffer tank that feeds the hydronic heating system (the radiators) registered a mere 90 degrees Fahrenheit, whereas it should have been close to 140. That explained the barely warm radiators.

The small touch screen on the boiler had a message for me: “174 Lockout safety relay feedback incorrect.” Great! If I only knew what that was supposed to mean – other than that something in the pre-ignition testing went wrong.

I don’t know why, but “The IT Crowd” came to mind. So, before making any panicked phone calls, I decided to turn the boiler off and on again. Et voila – once it booted all the way back up, it also fired up and I again had hot water running through our radiators.

That is where the story usually ends – but not so in the world of nerds. Why did I have a safety lockout with a code # 174? What could have failed in the pre-ignition test? Now was the time for phone calls.


My installer pointed me to the two items that usually cause the boiler to shut down. The flame sensor rod and the electrical spark ignition. Both of these components need regular cleaning and he recommended that I check the oxidation levels on the rods and polish them with fine sandpaper.

There wasn’t much oxidation on either the flame sensor nor the electrical spark ignition. I have the nagging feeling that something else may have caused the lockout.

Related posts:

Utility room pipe insulation

Tracking the unruly…

Connecting the unruly…

Wrestling the unruly…

Utility room installation

Utility room preps


Major milestone

January 10th, 2015
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Today was a big day. After five years, Cathy and I feel that we finally got a big step closer to one of our goals: Getting information about our project and information about energy retrofits into the hands and minds of our neighbors in North Lawndale.

This was a long road, but it wasn’t for lack of trying.

Yes, we had a number of open houses, with the last one (open house #4) being the best attended event. Visitors came from all over the city of Chicago and suburbs, which was also the case for the preceding open house. But almost no one from our community attended.

Yes, there is this blog. I have fun writing and publishing it and I am always amazed when I run into people who recognize me because they’ve read it. I am still surprised by how popular it is. But it doesn’t necessarily reach the demographic I want to reach most – the North Lawndale community.

And yes, our adventures have been published and featured elsewhere, such as on Chicago Public Radio. Did that help us connect with our community? Not in a noticeable way.

We have reached out to local community organizations whose missions clearly overlap with our deep energy retrofit goals, focusing on indoor air quality, material reuse and repurposing…you name it. Nothing panned out, despite numerous follow-ups.

It was only in the past couple of months that I came across a group right here in North Lawndale calling themselves “Men Making a Difference.” One of their goals is to help young adults from our community to enter into trade training programs.

That generated the spark through which we connected, and we organized a tour of our deep energy retrofit made up completely of local residents!


Five years in the making! I have to say that this felt like one of the most relevant events we’ve had to date. And I hope we have a lot more of this coming!

Related posts:

Open house #4 – as much Q&A as we could handle

On Air with Worldview

Project featured in Medill Reports Chicago

Open house #3…

1st Open house


Salvaging graystone treasures

January 4th, 2015
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Don’t let the blog post title fool you! I am still thinking and talking about our yard and vacant lot.

We have a yard, but you can’t call it a garden – yet. So what do we use it for? In the early days, during the deconstruction process, we staged the dumpsters in the yard.



Some yard space was repurposed into a material storage depot – which brings me to the graystone treasures.

We lost two vacant graystone buildings on our block in a massive fire during Thanksgiving night 2010. We didn’t live in our building at the time. But I stopped at the house to take care of a couple of tasks the day after Thanksgiving and was shocked by sight of two burned out building shells.

The good news is that no one was hurt and the nearest occupied building was evacuated and saved.

The burned out building shells were declared dangerous and emergency demolition started within one and a half days. With the demo crew came a team of brick salvagers. Rather than having the Chicago common brick dumped into a landfill, the salvagers pick the bricks out of the piles, clean the mortar off and stack them onto pallets. That is the kind of brick I can then buy for masonry repairs.


What nobody was interested in, to my surprise, was all the graystone from the building facade. It didn’t matter whether they were window sills, steps, plain graystone, carved graystone, columns, or ornaments.

The demo crew was happy to let me pick out those pieces. Less weight for them to haul off, and with that less tipping fees.

One of the buildings had beautiful carved front porch columns that, despite being knocked over, remained intact.


But boy, were those suckers heavy! At first, Cathy and I attempted to wrestle them with a dolly. Needless to say that we decided otherwise before either of us or the dolly got crushed.

I decided to replace the dolly with the truck and recruit as many strong help hands as we could reasonably fit around the big columns. Even with the amount of muscle, it was still a daunting task. To move the columns, we had to set them upright and swivel them inch by inch towards the truck.


Two columns and a sill was all the truck could take in one load. Each column must have weighed about 800 pounds.

Back in the yard, sliding the monsters off the truck and laying them down was a little easier than loading them.

We plan on using some of the pieces on the house, like the steps and some of the facade stone. Other pieces will probably become part of the garden, like those big columns. I am just happy that I was able to score those treasures, and safely transport them into our “material storage depot.”


The big question is – for how long will it remain a material storage depot?

Related posts:

From wish list to reality

Deconstruction (or rückbau)

Rebuilding the parapet


From wish list to reality

December 29th, 2014
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Back in 2008 and 2009, when we were house hunting, we had set a high bar: A house with good solar access, and a vacant city-owned lot to the south. Despite the flush housing market in 2008 and 2009, reality set in and that high bar quickly moved down a notch. Our focus turned to finding the right building, first and foremost.

We did, and in the process held on to the option of a vacant lot for extra garden space. Our house has a vacant lot to the east and west.

The lot to the west is owned by our neighbors. With most of our windows facing east, the eastern lot was the one of interest to us. But it was more of a mystery.


Our attempt to buy it from the developer who owned it didn’t work out. He actually disappeared at one point, resulting in another lot with an absentee property owner. Because we didn’t want the lot to turn into a dump, we kept it clean and maintained it for the next few years.

To our delight, we discovered in 2012 that the property taxes on the vacant lot hadn’t been paid. That’s when Cathy did a lot of research and stepped into action. Long story short, last winter her due diligence and excellent work got us the deed to the vacant lot through a tax sale.

Although we had to pay all the back taxes that were owed, the late fees and penalties that had accumulated, and attorney fees, we feel that we got a very good deal. We ended paying about 1/4 of the developer’s asking price from a few years back.

The dream of an adjacent vacant lot for extra garden space has graduated from the wish list to reality. Except that it doesn’t resemble a garden space at all – at least, not yet.

Related posts:

Dream home wish list

No vacant city lot

Here is what we bought…

Separating fiction from the fact


2nd floor perimeter framing

December 4th, 2014
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Its not just a framing job, like it was on the 1st floor. This is a framing and insulation job at the same time.

Let’s look back at the 2nd floor insulation strategy.


Because the 2nd floor exterior wall consists of two wyth, rather than the three, we have a little more room for insulation. We air sealed the building with two inches of closed cell foam. Following the foam, we planned on two layers of rock wool insulation, one layer behind the framing and the second layer between the studs.

This assembly gets us to a R-value of 40 at almost the same cost of the R-28 insulation assembly from the 1st floor.

Back to the job on hand. I decided that I should try to install the first layer of rock wool together with the framing, to keep things simple. The question was, how?

For once, it turned out to be simpler than expected. We put the framing together as usual and lifted the sections into place, making sure the bottom plate was in its final position. We tilted the top of the framing section into the room. That gave us enough space to start stacking the first layer of rock wool between the framing and the closed cell insulation.

Once all the rock wool was stacked behind the tilted framing section, we pushed it into a vertical position and attached the top plate.

The attic, the space between the ceiling joists and roof joist, was a little more complicated because it is a tight space. But we followed the same principles.

What is left now is to install the second layer of rock wool between the studs.

Once it is all done, this will be a very cozy apartment!

Related posts:

1st floor perimeter wall framing

Double duty

2nd floor closed cell installation

Blower door test – before insulation

2nd floor insulation strategy

2nd floor closed cell installation

3rd layer – rock wool insulation

Insulation preps – plugging the 3” gap

Insulation preps – 3” thermal break

Insulation update

The insulation riddle is back

Following the control layers

Insulation riddle resolved

Insulation – how much is needed

Insulation – which material cuts it

Insulation – starts with moisture management

Insulation – lots of conflicts

Insulation – how it started


Knock, knock – who’s there?

November 21st, 2014
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I don’t care! Stop knocking and let me sleep!

That would summarize my mood at the end of last year, just after we moved from the garden unit up to the 1st floor. I didn’t get much sleep, because something kept knocking, in the bedroom, right above my head.

When the heat came on, the knocks started in one- to five-second intervals and lasted for about one or two minutes. After the heat turned off, the knocking kept going for a while with a single knock about every five to 15 minutes.

No doubt the noise was coming from our hydronic heating system. My first thought was that I got something wrong with a deflection leg on the supply and return line to the bedroom radiator, which runs right next to and above my head.


After two nights of sleep deprivation, I’d had enough. I checked the exact pex tubing location and then cut a hole into the closet ceiling adjacent to the bedroom, just large enough so that I could stick my head through and inspect the deflection legs.

It turned out that the deflection legs worked fine. But where the horizontal pex tubing turned a corner from the ceiling down into the wall, it was firmly pressed against the drywall. (Image below shows the tubing before drywall installation).


The expanding or contracting pex tubing wasn’t sliding across the drywall. There was enough friction for it to jump in tiny intervals – thus the knocks.

I pushed a piece of cotton rag between the tubing and drywall, which stopped the friction, jumps, and knocking. I finally got my first good night’s sleep on the 1st floor.

The end of knocking?

With that fixed, is our hydronic heating system silent? No. We still have some knocking, although it is significantly less obnoxious.

Our steel radiators also have a certain expansion rate although it is significantly less than the PEX tubing. At the bottom of the radiators are offset bolts so that the they hang plumb.


Although the offset bolt is rounded, smooth steel, it again tends to have enough friction to jump rather than slide across the painted drywall. This is only a problem on the longer radiators. If it starts to bother me, I may take a small piece of thin fabric, such silk, and slide it between the offset bolt and the painted drywall.

Related posts:

Unruly tech talk

Radiator start up

Radiator connection preps

Baseboard radiator delivery

Radiator déjà vu

Anne Alt liked this post

Onset of nerdiness

November 14th, 2014
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Strange things happen once one embarks onto the deep energy retrofit road. For instance, a level of nerdiness sets in.

You don’t just turn on the thermostat in fall. You make a note about when exactly you turned it on. This year, it was the evening of November 1st.

Not nerdy enough? How about this:

Back in the day, when I was more than young – when I was a kid – a hybrid of joy and eager anticipation clocked in once a week, triggered by the release of the next episode of a science comic book.

Some may argue that things haven’t really changed that much, except that the comic book was replaced by the monthly arrival of our utility bills. I devour them almost immediately, and they almost always make for some interesting reading.

Such as our natural gas bill for last month, which claims that we used more gas in October 2013 than October 2014!


Therms 10/2013: 32.51
Therms 10/2014: 22.52

Average daily therms used 10/2013: 1.02
Average daily therms used 10/2014: 0.75

That seemed strange, particularly because this October seemed so unseasonably cold.

Well, let’s separate fact from fiction. October 2013 was cooler, at an average daily temperature of 50 degree Fahrenheit, compared to 51 degree Fahrenheit for October 2014.

That still doesn’t explain away the difference in natural gas consumption. Nor do the extra two days on the October 2013 bill, although they could account for as much as 2.04 therms. To get to the bottom of this, I have to turn to the Energy Recovery Ventilator (ERV).

With an almost airtight house like ours, mechanical ventilation is less a choice than a necessity. It maintains good indoor air quality (IAQ) by removing pollutants and excess moisture, and as such protects us from what is known as the sick building syndrome.

The ERV doesn’t just ventilate the building, but it also has a built-in heat exchanger, the enthalpy wheel. This makes it an extremely useful piece of equipment, particularly during the heating season, as we get a supply of fresh air without the typical heat loss.

We had our fair share of ERV problems last year, starting in October. The air in the building got stale rather quickly, with no functioning mechanical ventilation. To maintain good indoor air quality, we fell back on the age old method of non-mechanical ventilation – opening the windows.

The problem for us was that there is no heat exchanger when you open the windows. We got plenty of fresh air – but is was cool October air. With that we had a lot of heat loss, which led us to turn the heat on about a month earlier than usual.

And that, ladies and gentlemen, probably explains the difference of 10 therms in the gas bill between this and last year.

If you find this remotely interesting, you have officially joined the club of nerds!

Related posts:

Blower door test – after insulation

Picking an ERV

Design workshop

ERV – keeping the heat!

ERV performance test

ERV croaked – Part 1


Mr. Porch doesn’t talk

November 10th, 2014
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Communication makes projects tick. Well – good communication does. The lack of communication or “half-assed” communication tends to create tensions, discontent, and even conflict. Once that has happened it can derail a project.

I am sure we all have anecdotes of individuals or companies with communication skills or lack thereof. I consider myself lucky because so far I have had contractors working on our deep energy retrofit who kept me abreast, listened to me, coordinated with me, and returned phone calls in a timely manner.

It wasn’t just all luck. I did quite some research on our contractors, relied on referrals, and often informally interviewed them.

Well, no lucky streak lasts forever, despite research and referrals. Our porch contractor, Mr. Porch (yes, that is the name of the company) confirmed the schedule for the back porch demolition, only to not show up – and not even call to let me know or reschedule.


Another start date was confirmed – and that too passed without any action. Then a substantial addendum to the contract was e-mailed to me, with no meaningful explanation. I have been calling on an almost daily basis to seek clarification. All I get is voicemail, but no return calls. Mr. Porch doesn’t talk.

We are left in the dark and may have to postpone the porch project and start building it next spring.

Related posts:

The back porch project

Back porch preps touch-ups

Drew Schmitt liked this post