Joined on February 12, 2013
Last Post on May 9, 2013
@ May 9, 2013 9:13 AM in need help switching for oil to gasYou gave us good advice measuring our needed gallons per minute and getting an official heat loss done. There is definitely wisdom in not having a unit that sized incorrectly. We had a 150,000 BTU cast iron unit prior that was much too large.
For us, the combi unit was first verified to meet our hot water needs then verified to align with the heating needs. The out door temperature sensor is said to play a big part in efficiency. We were about to pull the trigger on the Triangle Tube then realized it was not going to meet our hot water needs. I believe it was you on this forum that explained the real life between brochure on that unit with the initial 50 gallons at only107 degrees or so, which was then verified with the manufacturer. Good thing.
As well, the Navien is about half the price of the Triangle Tubes but does not yet have the long-standing brand reputation yet.
We got the Navien set to 130 degrees on hot water, which does the trick for us.
By the way, for heat loss, it is not the simple method of 12kbtu for 500 sqft. They actually measure each room, factor in insulation, windows, exterior walls, factor in your region's design temp and add up heat loss per room to get the answer. The really good guys use a door blower test and can tell you where you have home sealing opportunities. We had some contractors try to convince us the square footage calculation alone was adequate enough.
In the end what we realized was, there are many correct answers, hence many correct choices. It then comes down to the unit quality, reputation, installer comfort and budget factors.
We are glad we took a time to research before pulling the trigger.
@ May 9, 2013 8:23 AM in need help switching for oil to gasHow is that thing running so efficient in my place if that were really true? I only have 3500 sq ft and my gas bills are really low. Just based on our gas consumption alone, it appears to be running efficient and correctly for our home?
Our installer indicated that the unit is set to modulate down to the required fire rate down to 17kbtu. From what we were told, the combi units will never have a matching rated BTU based on the difference between hot water demands and heating needs.
Isn't this true for all combi units out there?
@ May 8, 2013 3:44 PM in need help switching for oil to gasWe had an oversized oil boiler with the hot water built in previously.
Also, we got different opinions from just about every contractor that came in.
The WM with an indirect option was out of our budget.
It then came down to a 83% Cast Iron boiler with separate 50 gallon water heater or a Navien for the same budget.
We chose the Navien CH-240 and are very happy.
We have a 3500 sq ft home with 3 baths in Cherry Hill New Jersey. The Navien service center happens to be just down the road from our house as well, so having parts availability and support is good for our location, which helps.
The efficiency ratings on combi units is said to be a bit misleading, since on heating side can operate more efficiently then the other.
Assuming you have a traditional tank water heater, it may already be 50% through its serviceable life anyway depending on the model. Heck, why not have all new at once?
If you choose to go the Navien route, make sure you opt for the outdoor sensor. Also, get an installer that has attention to detail and knows how to install this unit correctly. Our installer even admitted he messed up a few things on his first few installations on these units. They have to be installed correctly and can be a bit less forgiving from what he indicated.
The unitis very efficient and our new heating bill is less than a quarter of what we were paying for our old 86% way oversized oil boiler. The savings for your situation would most likely depend on whether yours is correctly sized or not. Gas alone is roughly 50% the price of oil, so at least you should get that much logic would dictate.
The older Naviens were not so great when they were first introduced from what we were told. The ASME Stainless commercial version is the only one offered now and they did away with the troublesome early models. We were also told to stay away from the 180 version by contractors that installed many of these so far.
We followed the good advice people gave on this site and had a heat loss analysis done on our home. This helped eliminate many bad options quoted to us. Many of the installers we dealt with estimated units that were too large for our home, which we were told would impact the efficiency immensely with short operation heating cycles.
We are happy with our unit and proper installation. The unit has proven many installers wrong that said it could not possibly work for our home or that combis could never handle the hot water demands on our home. This forum and experienced installer tips were helpful in making an informed decision.
By the way, as a tradition on this forum now, you will see a whole bunch of folks chime in on how they hate Navien.
@ May 7, 2013 9:01 AM in Suggestions for frustrated and confused homeownerWe have three bathrooms running just fine on this unit, with kitchen and laundry room use. We have yet to have an issue with loss of pressure or not enough hot water.
All of the contractors that came out to the house agreed that either the CH-210 or CH-240 would work fine for our house. They also calculated the heat loss for the home.
Are you saying that this unit is really built for a 9000 square foot home installation by default? Seems extreme.
@ May 6, 2013 5:16 PM in Suggestions for frustrated and confused homeownerOur home heat loss was only 85k. It was the hot water demand that the unit was sized upon for us. Else, this unit modulates all the way down to 17k to keep efficiency up.
If you go with the Navien, please request the installer to put in the outside temperature sensor. It does not automatically come in the box for the unit.
We set our hot water temp to 130 degrees. You will need to calculate the heating "K Curve" setting for your particular area and house. That is important for this unit to get it right, or you will either be less efficient or not be able to heat the house well enough if set too miserly.
@ May 6, 2013 11:05 AM in Suggestions for frustrated and confused homeownerWe were on a budget, which swayed our choice. The quotes we received were the same price as putting in an 83% Cast iron boiler. So, given only those two options for our budget, this was a clear winner for our circumstances.
I agree, if we double the budget available to us and the Triangle Tube met our performance requirements, we would have chosen the Triangle Tube. They look like nice units.
@ May 6, 2013 9:13 AM in Suggestions for frustrated and confused homeownerYes, we have a newer one. It heats a home a bit over 3500 sq ft with no issue and runs 3 showers on a cold winter day without issue here in New Jersey.
As folks say, time will tell on the reliability, but the unit is very inexpensive and the build quality was rated well by our installers. The folks that install the newer ones swear by them. You could buy two of these units for the same price you would pay for one Triangle Tube combi or other brand. They say the earlier ones on the market were rushed to production and had issues years back. They eliminated the copper heat exchanger residential version and only sell the stainless ASME commecial version as their only combi option now, which has better materials. We hear those early ones were really bad.
Ours is running fine. This was the only combi system we could find on the market that would satisfy our heating and hot water needs. The Triangle Tube was close but the hot water part was not enough. So for us, it was this or a much more expensive indirect tank with separate boiler options. This option was about a third of the price compared to a Weil Mclain boiler and Indirect tank install based on quotes we received.
We are happy is all I can say. Runs fine and much more efficient than we expected.
Heatpro is correct though, if you truly are looking for a never touch it reliable unit, then a large traditional cast iron natural gas boiler may do that. It just would not be nearly as efficient and would take up much more space. They say those old designs last around 30 years. They sell ones that also have a hot water coil built in, but that means you have to even run that big cast iron boiler all summer long as well for hot water. The Navien came in around the same price as quotes we received for this cast iron option, which was a deciding factor for us.
One thing we learned, make sure your installer has done Naviens before. They are a bit different and require attention to detail during the install. When installed correct, ours runs like a champ.
@ May 1, 2013 8:46 AM in Taking out a 3 yr old Navian..We just installed one, so wondering which model this was? Was it the copper or stainless model? CH-180, 210, 240? ASME or non-ASME?
We spoke to some folks familiar with them and back at that time they had two different flavors offered during our research. One for residential with a copper heat exchanger and inferior construction. Then a commercial version was offered with stainless. We were told they got rid of the residential version and made updates to the commercial. We were also advised to stay away from the CH-180 and keep with either the 210 or 240.
Supposedly, the early units had some issues and folks with the older units were upgraded to the ASME commercial version for free at this point. Not sure of any details though, just hearsay. From our understanding, the 2010 models may fall into those early growing pain years during initial market introduction.
Any observations with the newer ones manufactured in late 2012 and 2013?
Good luck and thanks again.
@ April 29, 2013 5:28 PM in what size boiler woul you recommend?Triangle Tube has some pretty effective combi boilers for small homes.
That challenger could probably safely handle two people taking showers on the coldest day of the year with unlimited hot water. Plus it is very affordable. The Prestige is roughly twice the price but appears to be much better.
If you need bigger, you can go up to 240kbtu with almost 6gpm at 77 degree delta t on the coldest day of the year with other brand combis. That is roughly 3 to 4 people taking showers at the same time in a house these days.
Why complicate things and make them more expensive? This could potentially knock off a couple k off his parts list and free up a boat load of space.
We went down this same path of thinking when we chose our unit and ultimately this option made sense for our circumstances.
It works just as well as our old cast iron boiler in our home, which was over-sized previously, but for a lot less in operating costs.
@ April 29, 2013 2:51 PM in what size boiler woul you recommend?Sounds like Triangle Tube combi units could potentially be an option for you. Less expensive, less equipment to install. An option that may work for you.
Went through the same thing recently on a much bigger house.
We have a bigger different brand combi, but are pleased with the unit.
You will save a ton converting. 50% just in fuel costs these days plus whatever efficiency gain you get from the new unit.
@ April 29, 2013 11:12 AM in NG Combi Boiler versus indirect tank and boiler setupWe are very happy with our Navien. Trouble free so far. We just needed to pay attention on how to install it correctly. It is a bit different. Primary loop, sizing, monoflow T's, pumps on supply not return so reverse the mounts on your existing pumps, no pressure reg needed on makeup since built in, etc...
Chris on this forum was helpful for figuring out hot water flows for gpm and that this unit met our technical needs. So the hot water dictated our BTU's required, not the heating load side.
This particular unit modulates all the way down to 17kbtu if I remember correctly, so it can compensate a bit. I am assuming that probably gives some tolerances on sizing on modulating condensing boilers installs, but best to ask the experts on that one.
We looked at the Challenger, for around the exact same price, but you get less for the money and the flow rates advertised are a bit deceptive (107 degrees for first 50 gallons or so whereas the Navien handles our 3 full baths with no issue). The higher end Triangle Tube was also in the same ball park for the build quality was but cost twice as much as the Navien and did not provide the same hot water or heating output necessary to support our bathrooms and hot water needs.
We have a pretty big, but mostly well insulated home now. Our heat loss probably falls around 85 kbtu based on calculations.
I was originally concerned about the lag between the heater heating up hot water and getting to the showers. The unit is pretty fast to heat up though, which was surprising. Sure you will wait a few more seconds that having the water already heated up, but the family has not noticed any changes, so obviously is acceptable, maybe an extra 15 seconds I would guess to ramp up heating. We set our hot water temp to 130 degrees and seems to be the right setting for us. Heat loop temp can be adjusted for max temp as well.
For some reason, I could not find many installers out there that either knew anything about the unit or was willing to work on them. Almost everyone of them wanted to install a Cast Iron boiler or a much more expensive Weil Mclain with Indirect. Nobody had consistent answers or advice for our home, and just about everyone of the installers never had done a combi installation ever before. Only the guys originally from Europe knew there stuff it seemed.
For the money, this unit made a lot of sense to us given the reduction in parts to install. We ran the exhaust up to the roof, which we are glad we did as well given the wet vapor cloud the condensing units apparently seem to all put out when observing other units out there. The hardest part was all the plumbing rework. Good luck.
Also, the unit does not come with the Outdoor Rest Sensor in the box. Make sure you buy one. Call Navien support for their Curve formula so you can input into the control unit, it is not in the manual for some strange reason.
@ April 29, 2013 10:20 AM in navien and odr?We have the dip switches set to use external thermostats on ours. Have control unit mounted right beside our boiler and always keep on. Installed the thermo-resister outside and plugged into two wire cable for unit. Set the K-Curve based on the formula Navien customer support provided, which is not in the manual for some strange reason. Was pretty straightforward. Entire process took about 15-20 minutes for us.
On a side note, there are different resistances available on the sensors. Did you get the correct resistance sensor?
Do you have the dip switches set correctly?
As soon as the sensor was plugged in, the unit did its thing. If I can do it, anyone can.
Good luck with yours.
@ April 26, 2013 1:03 PM in navien and odr?We have separate stats and the outdoor temp sensor and things work great.
@ April 12, 2013 11:27 AM in Do I really need a Navien CH-240?I am sure any of the high efficiency Modulating Condensing boilers would have delivered the same results in our circumstances This one just happens to do hot water as well.
No, not affiliated with the brand, just had tons of people telling us this was not possible and not to do it with a combi.
This unit appears to have a skewed rating because it does hot water and heating all in one. It appears to be more efficient on one than the other. You would probably know more about that then us though.
The old boiler was an over-sized unit that was turning on and off quickly when heating the home and also did hot water. So this thing was running inefficiently since it was not sized to the house and had to be on all the time to maintain hot water needs, even though it was well maintained and tuned as best as possible. To your point, the savings realized here are an extreme example probably not very typical. That old boiler could not modulate down like the new ones now can. Plus, was heating water 24x7.
@ April 12, 2013 9:16 AM in Do I really need a Navien CH-240?Yes, the real efficiency observations are shocking, but that was a good thing for our Navien Combi Boiler.
This one is a natural gas unit, so I assume sooting will not occur like Propane?
This is based on actual gas usage numbers. The previous oil bill the year prior when running our previous 85% efficient cast iron oil boiler was $762 for the same month and the month had an average temperature of 29 degrees. This was a cast iron boiler that also provided hot water. It was well maintained and tuned as best as it could be for the home.
When running the Navien, the gas bill came in at $88, or 68 terms of usage this year for the same month with an average temperature indicated on the bill to be 26 degrees, which was colder. This is also a boiler that is a combi that provides hot water.
These newer condensing and modulating boilers can bring some amazing results, as is the case with this Navien as well. In our wildest dreams, we never expected our bills to be this low for such a large home.
As far as efficiency goes, real-usage numbers speak volumes here. These modulating and condensing boilers appear to be the future. This particular unit appears to be the only one on the market at this point that is sized correctly for a larger home as a inexpensive combi unit. We are fans of simplicity with older cast iron designs but at these types of savings, we wouldn't go any other way. This is a high-efficiency and effective unit at a competitive price to that of traditional cast iron boiler installations. Only wish that the American manufacturers would start making ones to compete. Only one that we could find in our research was Triangle Tube but that was not built with enough robust output to meet our demands. Other than that we were looking at indirect options which inflated the price dramatically.
At the end of the day, this modulating and condensing combination technology is winning us over by its savings thus far.
I feel bad for "Oil" sales guys these days.
@ March 27, 2013 9:36 AM in Customers are confused when it comes to gas conversions...This was our family's thought process:
We had a cast iron boiler that ran on oil and was consuming about $1000 of oil a month during the coldest months in Cherry Hill, NJ. This was not an inefficient boiler 85%, just was that was too big for the house and running in small start up and shut down times. We had service techs out to try and tune the thing, but we could only get it so good. We were dropping somewhere in the neighborhood of $7000 or more in oil fuel a year. Plus, the hot water was supplied from the thing as well. So, in the summertime, we had to keep that huge block of iron warm all the time.
We did our homework before pulling the trigger.
From our research, natural gas alone on the same unit would have saved us just on fuel costs alone. Almost half the price, about and rough equivalent $1.85 per gallon versus $3.75 a gallon. But that would have meant keeping the unit running all year long still.
Then, by the time we factored in putting a separate water heater and converting it, putting in a new front burner piece, chimney linings, and other parts, it would have run just a little under the same price as a new cast iron boiler, which came with a warranty and came with all the parts.
Then, the low cost combi options were considered. The nice part about those units is that everything is in one unit with no need for any additional equipment. The not nice thing is that everything is in one unit as well.
The quoted replacement cast iron boiler was an 80% efficient unit in that price point. The best-fit combi was a 92% condensing modulating from Navien that fit our heat loss and hot water requirements. There appear to be more historically proven brands like Triangle Tube out there that make smaller units like this one in the same price point.
The cast iron had the benefit on being more reliable since it is just a hunk of iron at the end of the day. Simplicity has its virtues.
So, for just about the exact same price between a combi modulating condensing 92% boiler versus a cast iron replacement at 80%, we went with the high efficiency because cost-wise it made sense in our case. We will see payback in safely under 2 years going this rate with fuel bills so far, but that is just our case.
But, if the combi unit was not available for that price point, then we would have been left with only Condensing boilers with separate indirect hot water tanks as a higher end option, which would have raised the price because they are more expensive boilers and and require an additional hot water heater or tank. So, if we were down to these options only, we would have probably went the cast iron boiler route since the alternative was twice the price and payback was over a much longer term.
To your point, yes it felt senseless to rip out and throw away a perfectly well running boiler. But the dollars and cents sometimes work out.
@ March 26, 2013 8:07 AM in Dear Homeowner1Yes, I must thank you for your advice from all of you on this forum. Chris, your gpm logic helped to get through things.
We appreciated the assistance. It was through the forum that we eventually found our contractor that did the installation within our budget.
@ March 25, 2013 3:35 PM in Dear Homeowner1In my case, I have roughly 250 feet of emitters, about half being cast iron baseboards and the rest standard fin copper at 3/4". Now, the piping getting everywhere probably makes that number closer to 1000 feet.
During real-world performance, my biggest hit with incoming 40 degree water is about a 10 minute heat-up time for my 120 feet of cast iron emitters. Once those loops start returning hot, then the system is cooking. This thing is pretty impressive with its heating capacity and how easily it took the house to temperature from a large degree variance on its initial start-up.
The flow rate is advertised to be 5GPM at a 70 delta T for hot water at 120 degrees. My real-world experience is that the unit can run three showers with no issues on a design day in New Jersey though. This is probably due to it being set for 130 degrees and having some cold mixed in, since real life application does not have the knob set to full hot. Have not yet attempted more yet though.
In my research, we could not find any other combi units that meet these performance specifications. Sure with an indirect, but not all in one unit like this one, especially for the price.
@ March 25, 2013 11:47 AM in Dear Homeowner1Yes, our family was happy to get something like this versus a 80% cast iron boiler with separate water heater for the same budget.
It was tough getting past the instant dismissal from most folks when bringing up the combi option. Your post sheds some light on that. We put a lot of effort up-front to make sure this thing would work for us, hence we have some strong feelings here.
It was tough when the homeowners knew more about the combi systems than the people quoting them. Some people that came out thought that the Challenger would work fine since the BTU output matched our heating needs but did not factor in the hot water needs for us. Many of these guys were probably going back to the office and doing web searches to get informed. We did our homework and eventually found people who knew their stuff.
Funny thing is, many of the guys we eventually found who had experience were from Europe. They apparently have been using combi systems for quite a while now over there. Is the US a little behind them in HVAC technology?
@ March 25, 2013 11:19 AM in Dear Homeowner1"I'd love to see the piping on this unit. I'm one of those that would never install or recommend a product that isn't ASME or "H" stamped as a boiler which sounds like what you have installed. Remember you only get what you pay for."
Just last week you are again claiming this is not a boiler. The post is from March 18, 2013 at 5:39PM.
Facts are facts. Get over it man! Not a big deal, we all have these moments.
@ March 25, 2013 10:30 AM in Dear Homeowner1Not meant to discredit, but help others avoid confusion. Your posts were very misleading when researching our options on a simple google search. These come up at the top of the results list.
Other contractors were pulling up your posts when quoting the unit for our family as proof as to why this was not a workable solution. This was a great source of frustration.
Sorry your feelings are hurt, but hopefully this avoids the hoops we had to jump through.
@ March 25, 2013 9:29 AM in Navian tankless gas water hearer / boilerIt is a boiler. Please stop posting bad information. It is very frustrating to homeowners researching their options.