Ask Caleffi

We’re diving deep into the practical mechanics of thermostatic and digital mixing valves, featuring the Caleffi 521 Series and the 520 AngleMix™. Moving beyond the spec sheet, we break down how these valves actually behave in the field, and why sizing design flow rather than pipe size is critical for performance. 

What we cover in this session:

Ever stayed in a hotel where you have to turn the shower on, go grab breakfast, and come back just to find "warm" water? In this episode of Ask Caleffi, the team dives deep into the "why" and "how" of domestic hot water (DHW) balancing.

Water is inherently lazy, it takes the path of least resistance. In a DHW system can mean that  the furthest risers in a building can be cold  while the closest ones hog all the heat. The crew breaks down the symptoms of an unbalanced system and compares the most popular so...

Which pressure reducing valve is right for your plumbing system? Sometimes PRVs require two valves in series. Hear how the guys get the pressure right in all sorts of applications, from sea to shining sea. 

Steady plumbing system pressure is the goal, what do you need to check if the pressure is creeping up? The team discusses the different types of municipal and private systems that bring pressurized water to buildings. Each water service is unique and PRVs can smooth out the delivery. Also, hear what type of debris the guys have found in the inlet screens in the field. 

There are always rabbit holes in hydronic startups. Find out how the team deals with the tricky task of keeping a hydronic system in good shape. Fluid quality and high-performance separators are key. Over the years, the guys have built 1,000 machines that will help in the process, tune in to hear what they are. 

Zoning options can be overwhelming, because there are so many choices and no two projects are the same. The team walks through the different zone valve and zone relay technologies you will run across in the field. Hear how you can set yourself up for simple installation and service.

The team is in the lab to talk about the best way to fill a hydronic system. They break these fill valves down and share stories from the field. Find out what questions you should ask your customer to determine if you should leave the AutoFill on or off. 

What happens in the field when you need to loosen a union to service a valve?  Do you always need to replace the sealing elements?  How can the Posi-Stop™ embedded O-ring union system help?  Which products are shipping now with Posi-Stop?

 
Former service plumber and current Caleffi tech. support ace Matt DeLuca joins the guys today to talk about Posi-Stop as a first-time guest on the podcast.  There are many tips and tricks that plumbers use in the field to get fittings to seal.  No need for creativity or guesswork with Posi-Stop.  An EPDM O-ring seal compresse...

In this episode, Greg and Dan talk to "the man, the myth, the legend" of zone valves, Mike Schreiner, Caleffi CTO.   Mike has been working with zone valves for his entire career and is pleased to share his wealth of knowledge to help our Ask Caleffi audience learn:

What's important when considering a zone valve?  How do you properly size?  What is the flow coefficient (a.k.a. Cv or differential pressure) and why is it important?  BTW:  there is a BIG difference between close-off pressure and system pressure!  Zone valves and actuators... say what?  In which applica...

What drives the adoption of solar hot water systems?  Are there specific factors that signal the beginning or end of a spike in system installations?  Which applications are always a good fit?  What qualifications do you need to work on these systems?  How do you evaluate a site to know if the location is good for solar?

In this episode, Greg and Dan are joined by Carlson-Holohan Industry Award of Excellence winning Caleffi Training Manager Bob Rohr.  Over his career, Bob has been all over North America to help install, commission and educate about solar...

Why should installers care about BIM (building information models)?  Could BIM help you avoid working around other trades in a crowded chase?  What efficiency gains are there with prefabrication? Can the files detect errors, before the product is even purchased? What is a digital twin?

In this episode, the guys are talking to Woody Dickinson.  Woody knows Caleffi's technical details like the back of his hand.  With BIM, he is able to take a career's worth of engineering knowledge and integrate it into three-dimensional construction files.  While BIM is often only used to make sure...

Do I leave the air vent cap open or close it?  Do you leave the AutoFill(TM) open or closed?  Where should you put the expansion tank?  Do you pump into the boiler or pump out of it?  Hydro separator or closely spaced tees?  Where should you put the air separator?     

In this episode, the guys have put together a few of the trickiest topics that come up often on the tech. support lines.  The questions are simple, the answers are more complex.  Dan and Greg will help put the questions into context, so you can un...

What has Steve Steve learned about the plumbing and heating industry since 1990?  What happens at the MCE Mostra Convengo trade show in Italy? What part of the Caleffi factory reminded Steve of Raiders of the Lost Ark? How do you, "automate for the best?"  What was Steve's favorite meal? Why has nobody interviewed this guy before?  

In this episode, Dan and Greg sit with Steve Smith to hear more about his recent trip to Italy to visit the Caleffi factory and visit Mostra.  He details some of the most memorable sections of the tour, on t...

How does Caleffi support a rapidly growing plumbing product offering?  What makes a great troubleshooter?  How do you train an apprentice in the first place?  Where is the best place to work if you are a Brewers fan and also a journeyman plumber?     

In this episode, the guys introduce the newest member of the Ask Caleffi team. Straight from the field, Matt DeLuca is a Journeyman plumber and expert troubleshooter. He talks to Dan and Greg about his background in the trades, starting in 2008.  He also shares the topic that has come up the most on...

Where does the water come from?  How do you know what pressure you need in a building? Are you over 80PSI?  Are mountain states the only ones who have big fluxuations in municipal water supply pressures?  What is a "noisy little guy?"

In this episode, the guys are throwing paper airplanes and talking about pressure reducing valves.  Our PresCal is sold all over the world, so we have seen some crazy applications.  Dan, Greg, and Cody discuss what pressures you should shoot for when adjusting a PRV.  They also explain why two pressure reducing valves...

How do you fill a radiant system with the least amount of headache, in order to get the air out?  Should you flush through the boiler side?  What takes the least amount of time? When is a fill cart helpful?  Is street pressure water enough to properly purge?

In this episode, the guys share their field experience filling manifolds.  Just like toppings on a hot dog, there is no one specific way to do it that everyone will agree on.  Dan and Greg go over the hows and whys for the different approaches.  They mention the specifics for th...

DHW recirculation systems can cause a lot of headaches, if not operating properly.  Quick troubleshooting is essential, especially in the multi-family sector.  How do you know what needs to be fixed?  What questions do you need to ask occupants and building managers?  Are all shower valves the same? Do you need x-ray vision?  

In this two-part episode, the guys interview Mark Eatheton.  Mark is a licensed Master Plumber in Colorado and an ICC licensed Master Mechanical Contractor.  He has worked on a variety of troublesome, multi-family DHW recirculation projects over the years and off...

DHW recirculation systems can cause a lot of headaches, if not operating properly.  Quick troubleshooting is essential, especially in the multi-family sector.  How do you know what needs to be fixed?  What questions do you need to ask occupants and building managers?  Are all shower valves the same? Do you need x-ray vision?  

In this two-part episode, the guys interview Mark Eatheton.  Mark is a licensed Master Plumber in Colorado and an ICC licensed Master Mechanical Contractor.  He has worked on a variety of troublesome, multi-family DHW recirculation projects over the years and off...

An expansion tank is a very simple hydronic system component, yet it can cause complex troubleshooting woes.  Improper charge expectations, waterlogging and sizing can all play a role.  How can you determine if the expansion tank is the culprit for nuisance relief valve discharges? 

In this episode, Cody Mack tells you how to whisper to an expansion tank in this service-focused conversation between three former field techs.  Should you trust a factory precharge?  How do you avoid "bear-hugging" an expansion tank to relieve an over-pressurization?  The guys cover the ways to put your best foot f...

There are a lot of boxes to check to install and maintain an ideal DHW system.  Don't worry!  The guys can walk you through it.  How do you verify a DHW system has been balanced properly?  Which circulators pair best with thermal balancing valves?  How do you find out if you are meeting your minimum flow rate for a point of distribution mixing valve?

In this Episode, Greg breaks down the components needed to operate the perfect DHW system.  Pipe size, recirculation pumps, balancing valves, point of use and point of distribution mixing valves all pl...

Pioneering high-performance magnetic separation, Caleffi North America has recently introduced DIRTMAG PRO.  Do you know what's new about this device?  Why is it essential to remove BOTH ferrous and non-ferrous debris from your hydronic system?

Greg and Dan discuss the technology behind this device, where it's located in a system and what's the difference between a DISCAL air and dirt separator and DIRTMAG PRO.   Need help sizing the PRO?  We're are here to help you at techsupport.us@caleffi.com.

Thanks for tuning in.

Heating season is here!  Don't panic.  Dan and Greg shine a light on the components that keep your boiler running well.  A clean and check should include more than a speedy look at the heat exchanger.  How important is communication with the homeowner?  How do you set expectations for future repairs?  What components can be cleaned or repaired easily?  Who do I call for help?  The guys answer these questions and more. 

Want to hear YOUR QUESTION on Ask Caleffi? 

Take this quick 4 question survey for your chance to hear your question in a future episode. ...

John 'Siggy' Seigenthaler guest stars on an episode dedicated to all things heat exchange.  How do you know which type of heat exchanger is best for your application?  How do you keep them clean and operating efficiently?  What is a convection coefficient?  Why is turbulence important?  Siggy answers these questions and more for hydronic and domestic hot water system.

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for your chance to hear your question in a future episode.

Survey:
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Our Ask Caleffi team phones a friend to talk about PEX connections and manifolds.  Where do you locate a manifold?  Which fitting systems work with which types of PEX?  What is the difference between plumbing PEX and heating PEX?  

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for your chance to hear your question in a future episode.

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Our Ask Caleffi team encourages you to think outside of the box on that next service call.  They share tips that work at getting YOU to the root of a service problem without wasting time and money.  They share their favorite technique:  "Phone a Friend" and why it's so important.  You'd be surprised at how much WE learn from YOU while walking through a service concern.  

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for your chance to hear your question in a future episode.

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Max Rohr, "a long-time listener and first-time caller," joins Greg and Dan during this Episode of the Ask Caleffi podcast.  Max shares his well-earned experience with radiant heating and cooling systems, placing a magnifying glass on PEX.  He discusses radiant heat sources, the benefits and versatility of these systems, and then dives into PEX variants.  Greg and Dan chime in to talk about maintenance, system protection, and tips.  

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for your chance to hear your question in a future episode.

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Energy metering.  Is that EASILY accomplished?  Are there well suited applications for metering AND can a building owner be confident about energy consumption?  (YES!)  Greg and Dan, our Ask Caleffi gurus, talk about energy metering during this episode of the podcast.  They talk Modbus-to-BACnet (say what??) and what applications are perfect for calculating BTUs in a specific space.  Interested in a real-life example?  No problem!  Dan digs into an actual case study of successful tracking of energy usage with the 7504 Series CONTECA heat energy meter in action.

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quic...

Straight from the Ask Caleffi Podcast studio, Greg and Dan dive into boiler protection.  Let's face it when high-temperature, mid-efficient boilers condense... it's a mess!  How can that be prevented?  Greg and Dan talk about solutions, including a "Swiss Army Knife" approach.  They discuss how the ThermoProtec thermostatic mixing valves work and where they should be piped with steel, cast iron, and copper tube style boilers to ensure that they automatically control the return water temperature, preventing condensation of water vapor contained in the flue gas.  Familiar with a soot vac?  Don't forget maintenance!

Want to hear YOUR Q...

A return guest joins Greg and Dan during this Episode:  Cody Mack, Caleffi training and education manager.  They get right to the point as they dig into perplexing PRV behavior.  You'll learn:

1.  Got noise?  How to size a PRV CORRECTLY.

2.  Step down pressure and how to manage.

3.  PRV maintenance

4.  PRV configurations

5.  Familiar with 5 Things You Need To Know?  Check it out on YouTube!

Thanks for joining us today.

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question su...

Greg and Dan share commonly asked questions from the Ask Caleffi Blog.  During this episode, they will zero in on plumbing products.  You'll learn:

→ Can you install a 121Series FlowCal upside down?
→ What is the maximum flow rate of a thermostatic mixing valve?

→ What battery is used for in an electronic mixing valve/control?
→ How do you clean a balancing valve?

Watch for MORE plumbing questions in the near future.  And... thanks for tuning in!

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 ques...

Greg and Dan share commonly asked questions from the Ask Caleffi Blog.  During this episode, they will zero in on heating products.  You'll learn:

→ Can I add an air vent onto a Caleffi dirt separator?
→ How do I determine head loss in a hydraulic separator?  
→ Can I order your Z-one zone valve with differing connections on the 2-way and 2-way bodies?  Any tips on how to order?
→ How do I clean an air separator vent?

Thanks for tuning in!

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question surv...

Greg and Dan invite "the dynamo of donut testing" to the series, the one and only Cody Mack.  Recirc creep is something that plumbers no doubt experience.  But, what is recirculation creep, when does it occur, what are the symptoms and - most importantly - what is the solution for your domestic hot water system?   They'll discuss ASSE 1017 and thermostatic mixing valves.  Can an aquastat be installed to fix the problem?  Are certain facilities more at risk?  What is the impact of piping practices?  Can I dig deeper (show me the resources!).  

Don't know Cody?  He serves as an edu...

What tech support questions does Caleffi get over and over again? You might be surprised! What to do with air trapped in a plumbing system? Can I install a thermostatic mixing valve upside down? Why is this pressure reducing valve over-pressurizing the system? Listen to Greg and Dan explain these and more.

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for your chance to hear your question in a future episode.

Survey:
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Thanks for the sound effects!
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You're ready to install a thermostatic mixing valve.  Interested in pointers to make your install be successful?  OR... you've got a mixing valve installed and it's not working.  Now what?  From the "before" call to the "oh, no!" call, Greg and Dan are here to make you successful with your customer.  They'll dig into how flow is controlled in the valve, what causes temperature creep, and tankless water heaters and their implications with these valves.  Learn about laminar flow, pressure drop, ∆T, pressure ratios and pressure drop.  How about maintenance?  Yes, Greg and Dan discuss calcium and lime build-up, too.  Did...

Greg and Dan welcome Kevin Freidt, Caleffi Director Product Management & Technical Support (a..k.a. The Dr. of Disinfection) to the microphone.  They explore the fascinating topic of Legionella bacteria and its impact in domestic hot water systems.  Kevin starts with "bug basics":  where does the bacteria originate, when is it dangerous, what causes it to proliferate and how is it contained?  He discusses dead legs in potable water piping systems and explains how water becomes "old."  Not familiar with the ASHRAE 188 Standard?  Take note!  It's an important reference guide.  The Ask Caleffi Team completes this podcast with an interest...

Greg and Dan are behind-the-mic to discuss why you may want to select an electronic mixing valve for your next application.  They discuss how this digital valve is different from a thermostatic valve.  Why would you install a valve like this?  How about trouble-shooting... will a digital valve make a difference in problem resolution?  "This valve is electronic... wires are involved for installation.  I'm a plumber.  Helpl!"  Our Ask Caleffi team offers plumber-friendly installation tips!  Thermal disinfection?  Anti-scald?  Now you're talking!  Thanks for tuning in.

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for y...

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for your chance to hear your question in a future episode.

Survey:
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Thermal balancing in Domestic Hot Water systems.  Why is it necessary?  (hint:  water moves into the path of least resistance)  What's the difference between manual and automatic balancing valves?  Where are the valves installed?  How are these special valves maintained?  (ahem.... water quality is key!) 

Greg and Dan are back to answer these questions and discu...

Want to hear YOUR QUESTION on Ask Caleffi?  Take this quick 4 question survey for your chance to hear your question in a future episode.

Survey:
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Mark Olson, Caleffi North America GM, joins Greg and Dan during this episode of the Ask Caleffi podcast.  They discuss problems that can result from poor water quality within a hydronic system that can rob its equipment of life and reduce energy efficiency.  They discuss prevention methods to help you on your next service call or new installation.

Thanks for...

Your customer's domestic water system is not delivering heat correctly.  What do you do?  You listen into this episode of the Ask Caleffi podcast!  Greg and Dan discuss ASSE 1017  Point-of-Distribution valves (not to be confused with ASSE1070!) and how to size them.  They stress the importance of understanding a thermostatic mixing valve's minimum and maximum flow rate thresholds when combined with pressure drop.  

Greg and Dan discuss what types of products will complement existing systems that do not have recirculation loops such as a "high/low" valve assembly or an electronic mixing valve.  Their goal is to help yo...

It seems that hydronic zone valves have been around forever. They are pretty bulletproof!  But do you hear about end switches failing?  What's going on?  AND... what do I need to know before wiring a zone valve?

In this Episode, Greg and Dan discuss this common question from our Technical Support line:  what's wrong with my actuator?  Our Tech Support Gurus find that the culprit is typically a misapplication of the "end switch", a.k.a. the micro-switch.  They explain the role of an actuator that contains a micro-switch and what kind of inrush thresholds are required to ope...