Joined on September 1, 2010
Last Post on July 22, 2014
@ October 1, 2010 10:44 PM in Boiler Room InsulationHow will this stop the amount of standby loss from the boiler being 180deg. constantly?
@ October 1, 2010 10:39 PM in Boiler Room InsulationI almost wonder why contractors keep installing tank-less boilers other than it's a cheaper way to replace.
@ October 1, 2010 10:27 PM in Boiler Room InsulationSorry Chris,
I was typing my post before yours had gone up. Didn't see yours until after mine had posted.
@ October 1, 2010 10:14 PM in Boiler Room InsulationIt sounds like you have a boiler with a tank-less coil to heat your domestic. With this setup, you will have a cold line going to the coil in the boiler where the water is heated and then a hot line out of the coil to your fixtures. If you have this setup, the boiler control must keep the water in the boiler @ 180deg. constantly to heat the coil any time domestic water is drawn thru it. The down side of this set up is that there is a great amount of standby loss up the chimney from the boiler being hot constantly. This is would be why you're hearing the boiler fire with no apparent demand on it.
A much better setup is to have an indirect tank which has its own loop from the boiler and only heats when the aquastat on the tank calls for heat. With this setup, the boiler only fires when there is call from a heating zone or the tank. It then becomes a "cold start" boiler. You would have to have some control changes in addition to the indirect. Outdoor reset is also a big energy saver as Chris said.
@ September 29, 2010 4:08 PM in Buderus BoilerI've installed several with no problems. The al. heat ex. will need cleaning annually, not difficult at all. Just rinse down the fire side.
The ECR 97gb looks even better, but not sure if they've released it yet. Really a sweet machine. See Ad link at the top of page.
@ September 27, 2010 11:21 PM in Boiler Choice Quandry: Installer Experience V.S. Boiler Design.1. Depends on the boiler. Can it take low temp. return water? How much head loss thru the boiler?
2. Depends on system piping, pump(s) and controls. You have to maintain a certain delta T thru the boiler, usually 20-30deg. Multiple pumps whith large pipes might push water thru the boiler too fast.
There is no certain answer without knowing all the variables on the job. There may also be more than one approach.
@ September 27, 2010 10:48 PM in Advice on Choosing a BoilerBrian,
You obviously are aware of this principle, but here are a couple of suggestions:
1. A lower cost option for a new unit would be the Navien "Combi" heater. Model # CH 180, 210 or 240. You size it according to your domestic hot water demand. It has its own built in heat ex., pump, etc. for space heating. 92%, PVC vent. Should be close to your price range.
2. A Buderus GB142/24 or 30 (depending on load calc.) as Clammy recommended. Or the new ECR 97GB which Wes Congleton at ECR told me is on the shelves now but can't be released for sale until they have the approval letter from ASME in hand (they have the number, but not the letter). I'm really dying to do one of these since I had the privilege of going to factory with a few other contractors and giving input as to what we wanted in a new mod/con. ECR listened and really did a super job on this one. Either of these would cost more now, but should last substantially longer than a water heater.
As the man says: "You can pay me now or pay me later."
@ September 27, 2010 9:50 PM in Boiler Choice Quandry: Installer Experience V.S. Boiler Design.Should be able to install almost any boiler correctly if he follows the instructions and particularly the burner set up portion. I'm very partial to Buderus' 3 pass when it comes to oil. I wouldn't consider a pin boiler. The Buderus cast iron is actually flexible and can withstand thermal shock that others can't. When coupled with their "Logamatic" control which provides outdoor reset, the fuel savings can be greater because the reset curve can be set lower. The installer might need some help if he's never done a Logamatic. The 3 pass is also much easier to clean.
Just my preference. I'm sure others have theirs. If you really like your installer, talk to him and see what he's comfortable doing. Also, will he be the one servicing it?
@ September 27, 2010 12:11 AM in Help with on demand and storage tank hook up.You said you're getting a Navien 240 with a circulator. Are you referring to the Navien "Combi" model CH240 that has a built-in circulator and heat exchanger for space heating, or the standard model **240 heater?
In either case, you would be defeating the entire purpose of a tank-less, on-demand heater by connecting it to 50gal. tank. The tank has a high rate of standby loss (especially a gas one), the tank-less has virtually none. The storage tank is necessary because the burner is only about 40K - 50Kbtu capacity.The Navien modulates its firing rate between 19K - 199Kbtu as the water flow rate thru the heater demands. This means that it will produce over 5gal. per minute of continuous hot water. That's enough to run 4 to 5 showers simultaneously! And it's doing this at 98% efficiency vs. 65% of a tank heater. If you need more hot water than this, the solution would be to twin 2 of the Naviens together, not the storage tank.
Also, a note on the occasional problem that tank-less heaters have of not firing at very low flow rates: One of my product reps. who is extremely knowledgeable tells me this is occurring when cheap faucets from the big box store are installed. The checks in the faucet don't hold and pass cold thru to the hot side - thus no flow thru the heater.
@ September 23, 2010 6:09 PM in Boiler replacementBuderus has (arguably) the best cast iron boilers on the market. Adding staging and outdoor reset should substantially reduce fuel consumption.
@ September 23, 2010 5:56 PM in Need help finding out capacity of recessed convectorsContacting ADP Products or First Company.
Just wondering: are you replacing these or the boiler? If you're doing the boiler, I'd recommend sizing it from a load calc., not the radiation's capacity. The convectors may be over-sized.
@ September 23, 2010 12:01 AM in Condensate Drain Pipe Maintenance1.Look for mold inside the pipe when you re-pipe it, especially the white, oat meal looking kind. If that's the case, you'll need tablets and maybe a UV lite as Don said.
2.If the pipe extends below the water line in the pump, then it needs to be shortened. It also appears that the trap is too deep in the pic. The EZ trap is really the best solution.
@ September 22, 2010 10:57 PM in solderless?We've been using sharkbites for about 4-5 years now with no problems at all as long as the pipe is clean and round. We do alot of outside wood boilers that run constant circ. @ 170 - 180 and haven't had any leak so far. They also work well for repairing a kink in radiant floor - no restriction as compared to a barbed coupling. Also good for transitioning from pex to copper - just make sure you use the insert on any plastic pipe. Certainly wouldn't do an entire job with them.
@ September 4, 2010 2:03 PM in Under floor hydronic hydronic radiant heatAs much as I love doing radiant floor heat, I must ask the question: is it worth it in this situation? You are are only talking about a small area where you are going to loose alot of floor space to cabinets and appliances which will produce heat. Doing radiant floor would be expensive with minimal r.o.i. You would absolutely have to create a separate low temp zone for the floor with all the apparatus necessary. You cannot run high temp on the floor. Unless you want to replace it in a few months due to failure from heat stress.
I would recommend using a toe kick heater such as a Beacon Morris "Twin-FloI II". It can run off your present high temp zone or you can zone it separately. My customers have always been pleased with these. They are very quiet and produce plenty of heat.
@ September 4, 2010 1:27 PM in radiant tube identifactionI've installed thousands of feet of O2 barrier pex that was red in radiant floors. Look to see if it says " oxygen barrier" or "type B" on the tubing. Another thing to look for is if the tubing has an outer shiny, clear coating on it then it's O2 barrier tubing.
@ September 4, 2010 12:31 AM in Have 2 leaky evap coils.. Replace with same or go genericUsing TXVs may give a slight increase in efficiency (1/2 a seer. point at best). But if your cond. units have recip. compressors, then you will have to add hard start kits to them. If you're trying to keep costs down, use coils with pistons (orifices) instead of TXVs. Also, TXVs are refrigerant specific: You can't use an R22 TXV on an R410a system. Pistons work with any refrigerant, but may need to be re-sized when converting to R410a. The're very inexpensive. Make sure your tech. sizes them correctly. The one that comes with the coil may not be the right size. A 2 ton unit should be around 061 and a 2 1/2 ton about 067. That's the bore size of the piston in thousands of an inch. The size is stamped into the side of the piston.
@ September 1, 2010 10:58 PM in Boiler SizingChosing a mod/con will also give you boiler reset (the boiler adjusts water temp. lower as outside temp. rises). This can cause significant savings that are not reflected in the a.f.u.e. rating. In your area one of my reps. is claiming 40% savings with outdoor reset! The fact that your radiation may be oversized only makes this better since the reset control could lower the water temp. even more due to oversizing. The lower the water temp. returning to the mod/con., the higher its efficiency. It could be running at 98-99% with cooler return water. You can't do this with a standard cast iron boiler: it can't take the thermal shock and / or condensation that would be produced.