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Joined on September 1, 2010

Last Post on July 22, 2014

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Hot Water Re-Circ and Legionella

@ February 22, 2014 11:34 AM in how prevalent is this?

For what it's worth: the final report that I heard on the original outbreak of Legionaires was that the source of it was the hot water re-circ line in the hotel, not a nearby cooling tower.

The 100* temp in the re-circ line was perfect breeding ground for the Legionella bacteria.

Mr. Mustache's system would produce about the same temp in the floor and then return it to the house for distribution through its shower heads.

But, because his system will save a lot on installation cost, such evidence can be rejected out of hand.

C.I. rads + baseboard

@ February 21, 2014 6:07 PM in Can't Get Baby's Room Warm

This combo is never a good idea on the same loop as you're proving first hand.

Electric BB may solve the problem and be cheaper up front, but you'll pay much more to operate it, especially if you have natural gas. These BB also get much hotter at the element which may be a concern with small children.

C.I. BB may help, but may not be the only issue in this equation. If you have large pipes feeding the C.I. Rads and 3/4" pex feeding the baby's room, there may also be a flow issue. Water takes the path of least resistance and it will naturally seek to go through the larger pipes.

The best solution may be to install a properly sized cast iron rad with the piping sized for the same pressure drop (feet of head) as the rest of the system piping.

Some pics of the boiler, piping and rads would be helpful.


@ February 21, 2014 5:46 PM in Will boiler/pump still work if both zone valves are closed?

The pump will turn on once a zone valve opens.

Why are you considering shutting the boiler off at night? Supposed energy savings? You probably won't see 2% because all the energy that you saved during shutdown has to be used to bring the structure back up to temp in the morning.

Your tenants won't like it either, and rightfully so. They paid for a heated apartment. If you did that to me, I wouldn't pay rent until you stopped. Most states have laws against it.


@ February 21, 2014 5:33 PM in Help!! staple-up insulation foil myth

Some, maybe most home inspectors do a good job. But then there are the ones that are real fountains of mis-information, like this one. Because they carry inspector credentials, home owners, and buyers, assume that what they say is gospel. I've been called out to houses more than once to have to refute some foolishness that a home inspector told potential buyers that was holding up a sale.

Everything that Harvey told you is correct. The main issue is heat transfer plates, not foil-backed insulation. With out plates, the heat output of the floor will be less than half of that with plates. But even that doesn't settle the matter. The real question is: does the floor, and any supplemental heat source, produce enough heat output to match the heat loss of the house at design temperature?

For what it's worth: I have 40+ years experience, several masters licenses and own a business that designs, installs and services radiant systems. I carry a class "A" Virginia license.

Ask the inspector where he got his radiant training and faulty info.

I get real tired of people spouting off info that they haven't researched and confirmed by a recognized authority.

40 minutes

@ February 20, 2014 9:52 AM in how prevalent is this?

That was a new one for me also. Maybe... Maybe 40 minutes of a strong enough concentration of chlorine would kill the legionella bacteria that's free in the water? Of course, the little internet genius didn't provide the concentration or any other data or the source for this claim.

But, what about the bacteria that's embedded in the bio film coating the interior of the pipe? Like you, everything I've read says chlorination in safe levels won't touch that significantly.

Not Surprised

@ February 20, 2014 8:53 AM in how prevalent is this?

I just went to his site and your comments still aren't posted. In fact, there are no new comments since the 2/18.

I can only surmise one of two things:
1. If Mr. Mustache is indeed an honest man (hopefully), he has been given ample cause by the comments here to diligently re-evaluate his system and admit its flaws.
2. If he's only concerned about his pocketbook and reputation, he's blocking any input that would bring his system into question.

Have you thought about emailing him directly to see how he responds? I believe that with your experience and position he would be hard pressed not to ignore you.


@ February 19, 2014 10:34 PM in Alpine Gas Boiler Venting Problem

The Alpine IS a gas boiler. The OP said it replaced an oil boiler.

Delta T

@ February 19, 2014 9:02 AM in panel rads, constant circulation, short cycling, outdoor reset, trv's, buffer tanks, mod cons, variable speed circulator

As you've observed, a DESIGN delta T is seldom the ACTUAL delta T of the system. However, the actual will come closer to the design as it gets colder out side and the demand for heat increases.

Don't confuse the differential and temp overshoot parameters of the boiler with the system deltaT.

Unless you have radiant floor heat, 20* is the standard DESIGN delta T for most American hydronic systems and it will more than suffice for sizing your buffer tank. Your over-thinking this and causing yourself more concern than is necessary. Again, if you want longer run times, up-size the tank; it won't hurt anything.

Regarding your piping: you are saying that the system connection comes out of the side (bull) of the Tees and the boiler water goes straight through the run of the Tees? What about an indirect? Do you have one?

Combustion Analysis

@ February 19, 2014 8:41 AM in Munchkin Boiler Problem

The combustion analysis needs to be done AFTER the boiler is thoroughly cleaned. This envolves more than just cleaning the flame rod and vacuuming out the heat exchanger. A proper cleaning will include using a credit card to remove ALL the debris between the coils of the HX and probably scrubbing it with a solution of CLR.

I can't stress enough the importance of the tech being properly trained to use the combustion analyzer. You need to ask them this. Having the tool is not enough; he needs to know how to use it. If I had the money, I could own an MRI, but I'd be clueless about the images when I looked at them because I haven't been trained to properly interpret them. Make them give a printout from the analyzer of the results and post them here. Hint: we don't care what the efficiency number is; it means nothing in properly setting up the burner.

Combustion Analysis?

@ February 18, 2014 10:47 PM in Munchkin Boiler Problem

Was this boiler ever setup with a digital combustion analyzer by a technician that is properly trained in the use of it?

Buffer tank

@ February 18, 2014 10:38 PM in panel rads, constant circulation, short cycling, outdoor reset, trv's, buffer tanks, mod cons, variable speed circulator

Take the minimum firing rate of the boiler and subtract from that the minimum load. The difference is the amount of btu's that the buffer tank must be sized to. You can over-size the tank and get longer run times, but don't under-size.

Your system is probably designed for a 20* delta T. This has nothing to do with the programming in the boiler, but the sizing of your emitters, piping, circulator, etc.

The three main variables in the formula are btu difference, minimum run time and system delta T. Minimum run time should be at least 10 min. Delta T we'll assume the standard 20*. You'll have to supply the btu difference. With these parameters, you'll need one gal. of storage for every 1000 btu's of difference between the minimum firing rate of the boiler and the minimum load. If you have a 30k btu difference, you'll need at least 30 gal. of buffer. The formula will confirm the same. I just gave you the short cut.

As far as piping goes, it depends on how your pri/sec piping is done. Is the primary piped where the loop goes from boiler supply to boiler return and the system connects to it through the sides (bull) of the closely spaced Tees? Or is it the reverse where the boiler injects into the primary through the bull of two closely spaced Tees? Is there an indirect, and if so, how is it connected?

Reset curve settings

@ February 18, 2014 9:59 PM in Short Cycling of heating...

Without a heat loss calculation, emitter sizes, piping and circ sizes, its not possible to give you a precise answer.

Does the system heat the house sufficiently when it's 5* outside? If so, then 160* water at 5* is sufficient. If not, you need to set it higher and for 5* outside! not 13*.

95* on the other end is almost negligible for BB unless it's low temp BB. I'd raise that to about 120* at 65* outside.

Again, just some general guidelines. You can experiment by raising, lowering and stretching the difference between the two. When you reach a place where the heat won't keep up, you know you've gone too far. Take it 5* at a time and give it a day or two of relatively cold weather to see how each increment effects the house.

But, get your t'stats programmed correctly first.

You're missing the point

@ February 18, 2014 5:36 PM in how prevalent is this?

Analogies are designed to illustrate a point, not be extended to ridiculous conclusions. It's illogical to reason from an analogy; we reason from truth. Any truth reasoned to an extreme becomes an absurdity. If I extended your statement about a doctor being the only one qualified to do surgery to the extreme that you have about cooking your own food, etc, then we would have to conclude that I shouldn't remove a splinter from my finger because that's surgery and only a doctor is qualified!

Your are indeed missing the point which was simply to show that you go to someone who's qualified when the need arises: i.e. You don't go to a mechanic to get a tooth pulled. Nor do you go to a G.C. to design a radiant heat system.

Then you stated that Bob was suggesting that anyone who tries to work on their own heat was "a complete moron because it's beyond the grasp of anyone but the most highly trained and experienced people".

You have totally fabricated this from your own mind. I challenge you to show where he said anything like that or implied it. By making such a false accusation, you have proved that you are obviously totally ignorant of what this site is all about. Just in this thread alone there are multiple posts by homeowners who state that they have received tremendous help from the pros here on doing repairs or installation on their systems. There are also thousands of pages of threads here that prove that your statement is outrageously false. Have you taken the time to read any before you start making such accusations? Obviously not. Your history shows that you just signed on today and your only posts are on this thread.

You've also missed the point of why the pros on here are so adamant about the real issue which is: Mr. Mustache is pushing a system that not only is loaded with design errors, but is potentially deadly to those who follow his advice.

But that doesn't seem to bother you. Instead, your upset about how some have commented about it. And you have the audacity to come on here where you've never contributed before and rebuke those who are genuinely concerned and who seek to warn others.

This is America and Mr. Mustache is entitled to his opinion about how to design a radiant system just as we are. But he's not entitled to pass himself off as an expert and then promote that system in a public forum when that system is fraught with errors and potentially lethal. Freedom of speech doesn't allow that anymore that it allows someone yelling "fire" in a crowded theater.

Why is it that you're more concerned about how we've expressed our opinions than you are about the issues with Mr. Mustache's system? Are you another one of the thought/speech police or do you care about real issues?

Water temp

@ February 18, 2014 3:53 PM in Short Cycling of heating...

If 150* will heat your house when it's 5* outside, then that's what you should use.

BB heaters are rated at 180* water. They should be sized based on AVERAGE water temp of 170* max (180* supply, 160* return).

If you using 150* supply on the coldest night of the year, that means your AVERAGE water temp will probably be 140* unless the system is over pumped. At 140*, the output of BB is half what it is at 180*.

That means you would need twice as much lineal footage of BB to get the same output as if the supply water was 180*. Unless the BB radiation was intentionally over-sized to allow for a 150* supply, you'll probably need 180* when it's 5* outside.


@ February 18, 2014 2:02 PM in Short Cycling of heating...

That's backwards.
180*@ 5* outside; 120*@ 68* outside.


@ February 18, 2014 1:58 PM in new at the wall


Plumbing and Surgery

@ February 18, 2014 1:46 PM in how prevalent is this?

No one said they were equally difficult. It was simply an analogy to convey a point. Obviously, it was lost on you.

Also, we're not talking about "plumbing". We are talking about Hydronics. And radiant floor heat in particular. Something most plumbers and HVAC people are clueless about. Then along comes Mr. Mustache, a GC, passing himself off as an expert in a field that he's woefully ignorant of and plying his ideas upon trusting people who take his advice as though he's some guru.
If you think this just involves learning to put pipes together and passing a written exam, then you're very much in the dark.

Mark Eatherton has over thirty five years experience and is president of the Radiant Panel Association, the nationally recognized authority on radiant heating. He has personally contracted Legionella and survived it. Therefore, he is passionate about its prevention.

Ice sailor has about 50 years experience in this trade. I think he brings a little more to the table than just putting pipes together.

I have over forty years experience, masters licenses in five trades and five years of college.

Others here could list similar qualifications. We contribute here for free out of our own time because we want to help others by giving back to an industry that has benefited us. Seeing bad advice being given to others that we know will result in serious problems and maybe even death is not something we're gonna let slide. It will be vigorously addressed and refuted. If that bothers you, too bad. You would do well to educate yourself a little before you come here hurling accusations and defending blatant and willful error. Most, if not all of the men on here are gracious and willing to educate and help others about our industry if approached with the right spirit. But if you come hurling stones, don't be surprised when the response is a mortar round.

Cycle Rate

@ February 18, 2014 12:15 PM in Short Cycling of heating...

You need to go into the installer setup for the stats and set the cycle rate down to one per hour. They come from the factory set for 5 per hour to accommodate forced air systems.

I would also have your reset curve set for 120* @ 68* outside and 180*@ design temp. If the heat doesn't keep up with those settings, bump up the 120* setting 5* each day until it does. Most likely, You shouldn't have to go above 130*.

Don't use setback; it's contrary to the logic of a mod/con. You'll have better comfort and economy leaving the stats set at one temp. If you're doing it for sleeping at a cooler temp, then don't setback more than 4* and just dot it for that zone. Or, better yet, just leave that zone set cooler and close the dampers in the BB in your bedrooms if necessary.

Cutting Corners

@ February 18, 2014 12:06 PM in how prevalent is this?

It doesn't make sense. We all want to save where we can. In fact, we'd all like to get it for free. But anyone with some life experience and a little comon sense has come to realize that you get what you pay for and cutting corners costs more in the long run than doing it right to begin with.

Anyone that would build a house that includes radiant should realize that's the Cadilac of heating systems and you're not gonna get that kind of quality by throwing it together with Yugo parts.

In my opinion, Mr. Mustache is preying upon people's technical ignorance and their natural desire to save money for the sole purpose of promoting himself and his own business interests. In other words, he's an internet snake oil salesman. How can any other conclusion be drawn when he's stated that he knows there's extensive knowledge and design required for these systems but he's found a back door around all that? He even posted a pic of a correctly designed and installed system as well as his hack job diagram. No, he can't plead ignorance. What other conclusion is there?


@ February 17, 2014 10:24 PM in chimney condensing issue

The flue connector is the part that connects the appliance to the liner. Insulating any part of the liner, particularly near the top, will help keep it hotter and reduce the chances of flue gases condensing.

For Sure

@ February 17, 2014 10:18 PM in i think i have discovered a new missing variable ,

Imagine what we could do if we harnessed all the hot air coming out of D.C.

Great Idea, Bob

@ February 17, 2014 9:33 PM in how prevalent is this?

Maybe you can do like Mr. Mustache and get all of us a group rate on surgical supplies, anesthesia, pain meds and bed pans too?
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