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Joined on December 29, 2008

Last Post on August 20, 2014

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Didn't want

@ October 30, 2009 12:38 PM in Viessmann WB2B Hot Water Priority?

to get into that but your right..Thought maybe the easiest way to overcome the objection was advise the guy to use Viessmanns Indirect that way his contractor would have no issues to speak of.  I'm with you on the comment.

Viessmann Indirect

@ October 30, 2009 10:15 AM in Viessmann WB2B Hot Water Priority?

If the contractor is so concerned about the sensor and you want a indirect tank and no issues then the best way to go is to use Viessmans CVA or EVI tank. The CVA will be less expensive than the Stainless EVI but it will cost you more than and Amtrol.

There Lies the Problem

@ October 29, 2009 6:39 AM in Viessmann WB2B Hot Water Priority?

You will not find even a mention of a zone valve in the installation maual. The Germans believe in pumps not zone valves.  He should be  zoning with pumps. See page 31 of the installation manual attached for a basic system layout. I also attached the other manuals so you can get a head start and educate yourself.
If this is an Amtrol Boilermate he has to remove the exisiting aquastat and probe and insert the Viessmann DHW sensor in the well. He can then pack the sensor with some insulation on one side to get the sensor to make contact with the side of the existing well to get the best readings. Has been done and will work.

Your the gentleman who e-mailed me


Your out on Long Island. I would suggest that you contact a trade professional out there. Rob O'Brien of Technical Heating is in your area he would be a great person to work with. You only get one chance to do it right so do it right.

Simply Wrong

@ October 28, 2009 6:17 PM in Viessmann WB2B Hot Water Priority?

That boiler is capable out of the box to do both. I'm going to assume by the WB2B that this is the new Vitodens 200 boiler. With this boiler he must purchase a seperate domestic sensor that is a accessory. Attached please see the tech data manual for the Vitodens 200 Boilers. There is a section for domestic water.

I don't understand what return water would have anything to do with this. The boiler is going to shut down the heat side and high fire to satisfy the domestic. The control on this boiler is capable of running 2 different heating temperature curves along with domestic out of the box.
Is he using the recommended low loss header and temperature sensor that goes in the low loss header to provide water temp supply feedback to the boiler? It sounds from your post that he is using either a Vitrol 200 or Vitorol 300 remote control sO I don't understand his logic concerning the domestic tank.
I would strongly urge you to educate yourself on this boiler.

You can design

@ October 26, 2009 7:38 AM in slab in basement how long to heatup

for what ever temp you want but a thermostatic mixing valve is the most primitive way to control radiant water temp. As stated you are looking for comfort. Why would you run the same water temp that you need on your design temp day on a 20 or 30 degree day? Isn't that the opposite of comfort. Why turn a system that wants outdoor  reset into nothing more than a on/off system?

I'd like to read this study that was referenced, does anyone have a link for it? Back to your I want to see 70 degrees on my thermostat. Didn't the gentleman who originally posted give the reason. The floor overshoots....With a lower water and design temp we can control the overshooting. When the zone is satisfied and that mass keeps giving off heat we can keep the room comfortable. This is more pertinent when there is no floor sensor.

How Long?

@ October 24, 2009 10:43 AM in slab in basement how long to heatup

An impossible question to answer. For starters the max water temp for Pex in concrete is 140 degree water. Once you start driving over that temp the concrete begins to crystalize around the tubing thus slowly reducing btu output until it cannot produce any at all. No different than scale build up in a coil.
Back to your question. You should never have overshoot of the therm if the system water temp is properly controlled. If you have a basic thermostatic mixing valve and running the same temp on a 20 or 30 degree day that you need at zero for the radiant it is a water temp control issue. In a properly designed radiant system we do not use 70 degrees as our indoor design temperature to calculate heat loss and water temp. We use 65. Some may use 68 but a properly designed radiant system never uses 70 degrees.

If you are overshooting you need a much lower water temp. Have a radiant heat loss done (notice I did not say a heat loss I said a radiant heat loss). Set the water temp needed for your design day. If a thermostatic mixing vlv, throw it in the garbage and consider using some type of control that will modulate the radiant water temp based on outdoor temp. The Taco RMB is what I call radiant for dummies, all the piping and pumps are done for you and it works great and is an easy installation. Check it out at [url=]

Boiler Choice

@ October 24, 2009 10:22 AM in best kind of boiler to buy - inputs welcome

Do not size of the boiler off the old boiler. Have a heat loss done. You will probably find that you have more radiation than the heat loss requires which means you may be able to start a lower heating curve. My boiler choice would be Viessmann Vitola. Lit is attached


@ October 19, 2009 7:29 PM in Radiant as supplemental heat?

of carpet is very high. Probabluy somewhere around an r-value of 3 maybe even 4 depending on the type or pad. Be prepared for having to use some high water temps to drive the heat. A must is a floor sensor for this application.

My boiler of Choice

@ October 19, 2009 7:16 PM in Radiant install questions

would be a Viessmann Vitodens 200 with a modulating 3-way mixing valve. I would add a Vitotrol 300 for indoor feedback  and be on my merry way.

Federal Tax Credit

@ October 18, 2009 7:59 AM in Tax Credits for High Efficiency Boilers

The only thing about the tax credit is that you only get 1 bite at the apple. IN other words get the best bang for your buck. The program covers more then just HVAC/Heating equipment. As for local rebates, in my market both utliities are giving $1,000 on 90plus, 300 on an indirect and $25.00 a program therm when installed in a new system. They are also giving $100.00 for the addition of outdoor reset controls.


@ October 17, 2009 11:23 AM in Taco ZR403 vs. ZR404

Need to use the SR Exp verision and add the PC600 card. This will give u extra end switch to run a domestic pump for priorty.

Ideal Radiant Temp

@ October 17, 2009 9:42 AM in Recommended Temperature

The ideal temp is the temp you need to overcome the heatloss at your design temp. For instance, if you design for 0 degrees outside as we do here and I need 120 degree water to get the btu output of the floor to overcome my loss then I need 120 degrees at 0. I don't need 120 at 5 or 10 or 15 or 20 or 30 degrees outside. I may need anywhere from 115 to 90 degree water to overcome the heat loss on that temps day.
My question to you would be how is the radiant controlled? In other words what are you using to get the water temp you need for the radiant, ie, mixing vlv, injection pump? If your using a water heater and just changing the temps without some type of outdoor compensation the system will never know what it needs on that day's heat loss. You'll be running up and down the stairs all the time to find your comfort range for each day.

Boiler Reliability

@ October 17, 2009 9:35 AM in high efficient or not

The reliability of a boiler like any other appliance is a reflection of the initial installation and the preventive maintenace. I have seen some of the best fail as much as some of the worse. It's all about who and how installed.

CI Rads

@ October 17, 2009 6:20 AM in ci rads

Drop me an e-mail. What size rads are you looking for? I have access to them.

Do the Heat Loss

@ October 15, 2009 9:30 PM in Radiant vs Efficient Furnace

Take the last job you just did and do a radiant loss vs a hot air loss. I never said AFUE. I have less of a heat loss for radiant period. The infiltration factor for forced hot air increases due to the amount of convection that is produced with forced air. This convection promotes a faster loss of energy through outside panels, windows or doors.
In radiant we have little to zero convection thus slowing our infiltration. This gives us a lesser required heat loss to overcome. So we need a smaller heating plant to overcome our loss versus yours. Meaning we burn less energy.
The heat loss difference is 35%. Let me ask you this. Take a 3,000 sqft house, well insulated, good windows and doors. Nothing fancy just typical. Generally what size furnace would you put in?

Before Boiler Choice

@ October 15, 2009 9:14 PM in Radiant install questions

How do you plan on controlling the radiant? What are you doing for domestic hot water? Curious before I give my boiler choice.

Size for 180

@ October 15, 2009 9:00 PM in Water Temp. to use Sizing Baseboard Heat

Use the 610 a foot for 180. If you boiler water temp is leaving 185 your return water temp should be 165. Don't lower the water temp unless you plan on doing a heat loss of all the other rooms and making sure that the footage of board in those rooms can overcome the loss at 170 degree water temp.  Don't worry about pipe loss. Worry about supply/return temp.

Couple of questions

@ October 15, 2009 8:50 PM in Pump SIze

Does that 300' count from the manifold and back to it or is there 300' in the floor and then leader lengths from and to the manifold? Are you running 100 percent water or is their anti-freeze in the system? Max loop length on 1/2" is 300' so you are way out on the curve. May have to use a TA009 or a Grunfos 26-99 depending on the anwser to the questions above. Keep in mind that we do not add up all the loops on the manifold. We only need to overcome loop that requires the highest head and flowrate. If we can overcome that we can overcome the others.


@ October 15, 2009 8:34 PM in Is an ODR really helpfull

Dump the coil, add an Indirect and zone priorty. I use Taco so in your case add another zone for the indirect and use a  ZVC-404EXP Zone Control then add the Taco PC700 reset card that plugs into the zone control. It's a simple install for a simple system like yours. Use the energy you all ready have being produced and are paying for. Don't add more energy usage as you will be with the elec wtr htr.  Rule of thumb, for every 3 degrees I can run my system below 180 degrees I save 1 percent of fuel.

Size the board

@ October 15, 2009 8:26 PM in Water Temp. to use Sizing Baseboard Heat

For what temp you need at your design temp. In my case here in NY my design temp is 0. See the chart I attached for the ratings. The lower the water temp you start with the lower the out-put of the board so the more footage of board you will need to overcome the heat loss at your desgin temp.


@ October 10, 2009 6:01 PM in Ok to transplant a burner

Can be set up with the proper combustion equipment. Before you make a decision I would suggest you give Burnham a call. That boiler may be covered or atleast a portion of it's value under warranty. It is handled a couple of ways. They will send a replacement jacket block but the contractor will have to strip your current boiler of the burner, aquastat and the other essentials and put them on the block. They also offer a rebate on warranty boilers. They would rather see you up-grade to the new V8H or MPO. Speak to them prior to doing anything. The V7 series of boilers had a mass leaking problem. Let me guess, it's leaking 2nd section mid.