Joined on January 19, 2012
Last Post on December 13, 2013
@ December 13, 2013 9:07 AM in Two Boiler WiringHere is the link for Idronics www.caleffi.us/en_US/caleffi/Details/Magazines/.../idronics_10_us.pdf
The Taco wiring is here www.taco-hvac.com/uploads/FileLibrary/100-92.pdf
@ December 13, 2013 12:18 AM in Radiant ceiling/wall in HE homeSiggy is excellent, you are off to a great start.
Your low mass approach is dead on.
I would design the panels so that they will work at the lowest water temps possible. All high efficiency and alternative heat sources prefer lower temps. Condensing boilers, heat pumps, solar panels ect. all thrive at lower temps. I would not go any higher than 120 degree water temp on the design day.
I have used Uponer joist track in walls with great success. They provide some great resources like the CDAM design manual.
Many super smart folks on here, welcome.
@ December 13, 2013 12:03 AM in Flow issueIs the pex in the joist bays bare tubing of are there alum plates?
What is the history of this problem? Did it ever work?
Forget what you think you know about circulators. The rating you are looking at are GPM at minimal head. Your system has lots of head. The correct circ for you system will be able to move the appropriate amount of water at fairly high head.
It is likely that there are several things combining to cause the problem. Many wood boiler setups have a undersized supply line. My experience with central boiler is that they have very little design knowledge.
Post as many details and pictures as you can.
@ December 12, 2013 11:30 PM in Two Boiler WiringCheck out drawing 6-14 on page 29. I think I would do it like that if I did not need a buffer tank. As the manual points out, buffer tanks are a good idea with wood boilers.
How are you dumping the extra heat?
As far as the wiring goes, I think that the whole thing would run simply and totally automatically if you just use the circulator output on the wood boiler control to set off a chain of events. Any time the wood boiler is hot, the circ will turn on. If the wood boiler runs out of wood, the circ will turn off. If you intercept the power to the circ with a relay, you can power on the oil boiler anytime the wood boiler is cold and their is a call for heat.
I would clean up the zone valve t-stat wiring with something like a Taco ZVC406-4.
I can draw it up for you if you would like.
@ December 12, 2013 12:45 PM in Flow issueHow long are the runs?
What diameter tubing?
@ December 12, 2013 11:20 AM in Two Boiler WiringIs this thing already piped?
Is it an outdoor boiler?
Do you want the change over automatic or manual?
The easy way to do this is with double pole double throw relays and an aquastat.
@ December 12, 2013 11:04 AM in Triangle tube not reaching setpointI think you understand that the underlying problem is the BTU hungry slabs pulling down the boiler. This really is not a problem unless it is causing the upstairs to underperform.
If it becomes a problem you could either control it "smart" with a system like Tekmar or you could throttle the slab circuits so they cannot take so much heat.
@ December 11, 2013 9:26 AM in Keeping circulators always on in unattended home to prevent freeze damageThe constant circ will work..... until the power goes out for a few hours.
If you have a vulnerable system, you really need antifreeze.
@ December 11, 2013 12:12 AM in Best practices for thermostat settingsWhat Gordy says is especially true of heat pumps. They are very inefficient when overworked. I would go with a lower fixed setting.
@ December 11, 2013 12:01 AM in New install: choose propane or oil?There are a few T-stats with built in limits on the market. The problem with them is that the tenant may be able to tamper with them. They also cannot be adjusted higher than a certain point. People like to turn t-stats up. I say, "let them". you can turn it up to 90 degrees, it just won't get hotter than 70.
If you take a device like this http://www.pexsupply.com/Tekmar-150-One-Stage-Setpoint-Control-4149000-p?gclid=CMm74uqvp7sCFUQ6QgodBXIAcA
and wire it in series with the existing thermostat, you will limit the max temp in the unit.
You do need to run an extra 2 wires and install a sensor somewhere in the unit. The setpoint controller would live in the boiler room where only you have access.
@ December 10, 2013 5:02 PM in Best practices for thermostat settingsIt sounds like you have a forced air heat pump?
Are the ducts in an uninsulated attic?
@ December 10, 2013 5:00 PM in New install: choose propane or oil?You can get real close on your cost per btu using the spread sheet. Once it has run a while you should be able to fine tune the numbers and get it exact.
If you decide to build the cost into the rent, you should devise a way to limit the heat in each unit.
I have an apartment that is set up so the tenant can have any temp they want up to 70.you can set the thermostat to whatever you want it just won't get hotter than 70.
I have only had one issue where the wench decided she needed a portable electric heater which she actually hid during the day and took out at night. A separate electric meter would be nice.
I think if you look at the install costs as well as the increased maintanance of seperate boilers, a central system looks pretty good.
@ December 10, 2013 9:26 AM in New install: choose propane or oil?In that scenario,you would install a BTU meter on each zone. You could read the BTU meters monthly then divide the monthly bill based on usage.
Fuel costs vary so much by region that I would still try to figure out where you stand.
Oil burners will be about 80% and high efficiency propane is more like 90%.
@ December 9, 2013 9:53 PM in New install: choose propane or oil?This is very simple.
Converting the whole building to electric is the easy answer.
Everyone already has a meter, it will be much cheaper to install. It may even cost the same to run (you would know if you used the spreadsheet SWEI posted)
It is the ultimate slumlord solution. No hassles.
If you want the most efficient option, that would be a single condensing propane boiler plant and BTU meters to keep track of the usage of each unit. I don't think it is the right answer for you because it may cost more up front and you don't see efficiency as important.
@ December 9, 2013 9:37 PM in Cold spot ?You need to find out the heat loss for the space then size the heater to the heat loss at you water temp.
It sounds like you have limited space, would a towel warmer work?
@ December 8, 2013 6:54 PM in one zone out of 3 is not workingWhat type of zone valve and what type of Taco controller do you have?
A picture would be helpful,
@ December 8, 2013 6:51 PM in Still no heat after replacing Taco PumpDo you have and know how to use a voltage meter?
You need to narrow down the problem rather than replacing parts.
The first thing most technicians would do is determine whether the circulator is getting power.
@ December 8, 2013 11:45 AM in wiring a tekmar 519 tstat to sr506That detail should work for you. The drawing on the bottom of page 9 of 16.
Are you tying the commons back together in the mechanical?
Instead of going too 7 and 2 on the 003, go to R and W.
Hope that makes sense, The t-stat control and the sr506 relay both need a common to work correctly.
@ December 7, 2013 11:29 PM in Furnace and hot water heater keep going offHas anyone tested the gas pressure? They should watch the pressure as the different appliances fire.It would be best to do it when it is cold outside.
A good gas contractor should also be able to do a combustion analysis on the appliances and check the draft in the chimney.
The guys you have had look at it are making pretty good guesses. You need someone to thoroughly check the entire system.
@ December 5, 2013 8:19 AM in Taco Bumblebee CirculatorIs the sensor in the proper location? Is it secured and insulated?
A 10 degree delta T is not a bad thing. The circ may be running at it's lowest setting.
Are there performance issues?
@ December 4, 2013 11:34 PM in Taco Bumblebee CirculatorHere is the manual.
How are you using it. What mode is it in? Sensor?