Hi All, This post details a proposed new system I have been working on, for the purpose of getting feedback on my choices of equipment (main components) and general setup. The next phase will be to generate a complete wiring, piping and venting diagram once I have decided conclusively on the equipment, and lastly to set up all the equipment so it is properly calibrated for the application. I currently have a 34 year old oil boiler which is used for heat and DHW. DHW is a coil in the boiler and heat is a coil in an air handler. The boiler is rated at 110k btu but I can’t tell if that is input or output, and I am also not sure of the nozzle size on the burner, which is a Carlin and newer than the boiler. The maintenance sticker on the side that is filled in by the servicing oil company indicates efficiency of about 65% and a stack temp of about 705 F. I’ve spent most of the fall designing what I think is the best system I can come up with, and still have some questions about some install details. Also any other feedback or suggestions are welcome. I’ll detail the system here and try to keep it coherent. The plan is for myself and a friend, who works and is licensed in the field, to install the system next to the current system over this winter and place it into service in the spring. I would be doing the work, including design and installation, under his occasional supervision and then have him do the final pipe fitting and startup/tuning so it’s all legal and properly permitted. The house is a 1300 sq ft ranch built in 1964 plus another 900 sq ft of newer finished basement. Most of the windows are original single pane, I have replaced 4 and counting. Attic averages about R40. Walls are 2x4 with no added insulation, except for 2 BR’s that were redone with R13. We calculated heat loss at about 55k. The new system will remain an oil fired boiler, and will add a 40 gallon indirect DHW heater. Total of 1 zone, plus the indirect. Boiler: I’ve settled on a Buderus G115/WS3 84k BTU output boiler. They seem to have a great reputation and look cool. I want the system to look really good and clean when it’s finished, something I can be proud of aesthetically as well as functionally. Also they seem to have the most detailed documentation available for proper use and installation that I found. Further, although I gather most boilers can be overfired, Buderus seems to be more officially on board with that than the other brands, and includes the official setups for this in their literature. We do plan to expand the house during the projected life of this unit, and I am also worried about the 84k input to the DHW…it is on the low side of what is recommended. Boiler Questions: The flue on this boiler is 5” diameter, with a stack temp of about 400 degrees with a Beckett NX. My chimney flue is 8x8 ceramic, and is in conditioned space in the basement and first floor, then another 6.5’ unconditioned through the attic and outside. Do I need a liner? Right now my stack temp is about 705!! Burner: I’m pretty much decided on Beckett at this point, due to availability of both techs to work on it and parts. Originally I was going to do direct vent, as it would have freed up a chimney flue to install a wood burning stove later, but the boiler location in basement is not optimal, plus the house is white. I also read that extreme cold weather can cause combustion problems when fresh air is piped directly to the burner, so I will install a 4” vent with a termination in the vicinity of the boiler instead of connected directly to it. The boiler is going to be in it’s own room so I am not too concerned about too much cold air coming in. In addition to the 4” vent I will probably install another vent in the side wall to try to minimize conditioned air being sucked into the boiler room and up the chimney through the barometric draft regulator on the flue. Burner Questions: My original direct vent plan required a Beckett NX. Now that I will be venting in the chimney, I could use an AFG, which seem to be much cheaper. It looks like both can be used with the sound deadening enclosure, which I do want. Is there any other reason besides direct venting to still use the NX? Or is the AFG just as good for a chimney vented application? The Beckett website has all sorts of fancy pictures of the NX flame and whatnot, but is it really better? Also I have heard good things about a Tiger Loop. Is this something I would benefit from, either in reliability or efficiency, or both? It is a single line gravity system with a basic foam filter. Control: At this time I don’t plan to install the Buderus 2107 (logamatic). I plan to use a Tekmar 260 (1 zone, plus DHW priority), and I’m not even really sure I will get much out of the outdoor reset. It looks to me like the 2107 does a bunch of fancy things I don’t need, that are suited to radiant systems and other low temperature/mixy stuff. At less than half the price the 260 seems more than adequate for my very basic 1 zone + DHW system. Control Questions: Do I need to worry about shocking the system after a long call for DHW, then an immediate return to a heat call, where the water in the heating coil loop has cooled significantly? Particularly since the boiler will be undersized for the indirect, it may take even longer than usual for the DHW call to be satisfied, leaving the heating coil even cooler. The 260 has a function that mixes the 2 for a short time in this event, is this an adequate solution to not wreck the boiler? Or so I need to install a “real” mixing valve system in the return? Also, am I right to say I wouldn’t be gaining anything by using the 2107? I really can’t see what it would add to such a basic system, am I missing something here? Lastly, the 260 has 2 purge settings: After a DHW call ends, it does a 4 minute purge or until the boiler drops to 160. But after heat call ends, it only purges for 20 seconds. Can anyone explain this? Why would I not want maximum heat purge out of the boiler in both cases? Would it be a good idea to add a relay to change this? Indirect: Although it looks cool, I am not going to go with the matching Buderus logalux. I wouldn’t stack them anyway, as I have plenty of room and it would double the trouble if one failed. They are also more than twice of the price of a WM Gold Plus 40 which seems good enough to me. If anyone has suggestions of an indirect that is particularly suited to this applications, by all means…. For the past year, I used about 30 gallons of oil per month during the no-heat-at-all season for DHW, and a max of about 120 gallons a month during peak heating season (Dec/Jan/Feb), for a total of about 1000 gallons. My highest expectation is that this will reduce consumption by 30-40% although direct comparison will be impossible, as next winter the house will not be the same (more replaced windows, and insulation etc) and probably the thermostat will not be set the same either! The other goal is to have hot water that can be used for 2 applications at a time, and not require constant adjustment through an entire shower to avoid scalding or shivering. Thanks to all who may offer their feedback, it will be appreciated. Nothing is set in stone yet. Over this winter I will take my time and build this system right next to the old one, and when it’s ready we will just have to do the hook ups. Mike

Is there a warranty on Honeywell R8182H Aquastat Control? I purchased this item a little over 10 months ago and it appears to have a problem. None of the literature I got with the item mentions a warranty. If yes, any info including contact info would be helpful. The problem is as follows: When any of the 3 zone vaves (Taco 572) call for heat, the boiler fires up if the temperature is below the high limit setting as it should, but the circulator does not turn on as it should. There appears to be a low ac voltage (3.2vac) but not the 120 VAC on terminals C1,C2. The circulator was disconnected from C1.C2 and connected directly to a 120 VAC source and it works fine. I had this same problem on a similar R8182H unit 10 months ago, after 28 years of use, and replaced the R8182H unit which solved the problem. That unit also had high & low limit settings that were not accurate for a couple of years as mentioned in other posts. Replacing the unit also resulted in accurate high & low limit settings. It seems unlikely that I would have the same problem after only 10 months of use on a new R8182H unit. Is there anything that could cause this to happen?