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Neat: Navien tankless boiler

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Kaido

Elite Member & Kitchen Overlord
My buddy just got one of these:

http://us.navien.com/

Retrofitted his existing baseboard heater system & water heater tank with it. Pretty neat. Didn't know people still used boilers anymore (then again, I moved up north from the south, so my experience with heating systems is admittedly limited to what my house has), but seems like a really nice idea for both home & water heating. Hadn't heard of this one before.
 
Yeah, tankless condensing boilers are great. I had my garage slab set up with pex tubing for a future boiler install. I opted to run a pellet stove this year as LP prices are still out of control, but hopefully the prices drop enough to make it worthwhile.

A navien was on my short list of heat sources.
 
terrible reviews on amazon. hopefully it works out for him 🙂

He said it's worked out pretty well for him so far. My only complaint was that the hot water was skin-meltingly hot :biggrin:
 
Yeah, tankless condensing boilers are great. I had my garage slab set up with pex tubing for a future boiler install. I opted to run a pellet stove this year as LP prices are still out of control, but hopefully the prices drop enough to make it worthwhile.

A navien was on my short list of heat sources.

Yeah, he's building a combo system - the house he got has a somewhat weird design, so he bought a pellet stuff to put in the middle of the basement & the pipe it up through the hallway to flow into all of the rooms. So depending on other fuel costs & how cold it gets, he can do a combo system & pump out even more heat & also save money depending on what makes more financial sense. Pretty neat!

My ideal setup would be a Mr. Slim in every room (mini-split ductless, but with the special H2i feature that can pull heat from like -13F weather outside). The problem is that they don't have a good consumer central control system for them, and also they don't make a smaller unit for bathrooms. But I'd still want locations like that heated & cooled, so I dunno. Spacepak looks pretty neat as well, have a friend putting one in this summer, so I'm anxious to check it out (high-velocity system with small tubes for airflow, really neat).
 
we have a Buderus, similar unit, have had it for nearly a decade,

thing is pretty awesome

we also have a Mr Slim in the kitchen

about the skin melting hot comment, you can adjust them so this doesn't happen
 
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My ideal setup would be a Mr. Slim in every room (mini-split ductless, but with the special H2i feature that can pull heat from like -13F weather outside). The problem is that they don't have a good consumer central control system for them, and also they don't make a smaller unit for bathrooms.

They do make all of that.
The indoor portions can be linked and zoned, also 2 and sometimes 3 (depending on size) indoor units can be run off 1 outdoor unit.
They can be controlled individually and/or from a central location.
I've had it installed in several projects for customers.

The problem may be that you are not dealing with a genuine Mitsubishi dealer/contractor, but just a general AC contractor.

Any AC contractor can buy Mr. Slim or Mitsubishi units from a distributor, but usually only Mitsubishi dealers/contractors are fully trained and keep current on all products and how to integrate them together.
Mitsubishi refers to them as Diamond Contractors.
Ask for one that does both residential and commercial.

Start here http://www.mitsubishicomfort.com/
And then feel free to contact the regional Mitsubishi Comfort office in your area.
Mine is in Atlanta and they were very eager to help (I'm a GC) and even pointed out several Diamond Contractors in my area that they could confirm were excellent (as with any profession, not all contractors are equal in experience, knowledge, or quality of work). 😉
 
we have a Buderus, similar unit, have had it for nearly a decade,

thing is pretty awesome

we also have a Mr Slim in the kitchen

about the skin melting hot comment, you can adjust them so this doesn't happen

Nice, can you set the faucet water temp separately from the boiler for room heat?
 
They do make all of that.
The indoor portions can be linked and zoned, also 2 and sometimes 3 (depending on size) indoor units can be run off 1 outdoor unit.
They can be controlled individually and/or from a central location.
I've had it installed in several projects for customers.

The problem may be that you are not dealing with a genuine Mitsubishi dealer/contractor, but just a general AC contractor.

Any AC contractor can buy Mr. Slim or Mitsubishi units from a distributor, but usually only Mitsubishi dealers/contractors are fully trained and keep current on all products and how to integrate them together.
Mitsubishi refers to them as Diamond Contractors.
Ask for one that does both residential and commercial.

Start here http://www.mitsubishicomfort.com/
And then feel free to contact the regional Mitsubishi Comfort office in your area.
Mine is in Atlanta and they were very eager to help (I'm a GC) and even pointed out several Diamond Contractors in my area that they could confirm were excellent (as with any profession, not all contractors are equal in experience, knowledge, or quality of work). 😉

Can you elaborate more on the interface system? This is what I know so far:

1. The standard Mr. Slims operate off an included wireless handheld remote control. $99 replacement:

http://www.amazon.com/Mitsubishi-Electric-E12C30426-Replacement-Remote/dp/B00G3NALLG/

2. A wall-mount wireless thermostat-style control is available for $335:

http://www.amazon.com/Wireless-Remote-Controller-Reciever-Kit/dp/B008MB3UM4

3. Europe has MELcloud for control, which includes support for iOS, Android, and Windows:

http://www.melcloud.com/

Interface is via a Wifi adapter:

http://innovations.mitsubishi-les.com/en/controls/wifi-adapter

4. We get the crap "Zone Control" version using M-NET in the U.S.:

https://itunes.apple.com/us/app/mitsubishi-zone-control/id385943152?mt=8

But that only operates off Mitsubish's commercial offerings: CITI Multi, M-Series, and P-Series via the following central controllers: AE-200, AE-50, AG- 150, EB-50, GB-50, GB-50ADA, or GB-24. Note that these aren't consumer-grade interfaces & are made for buildings like businesses or apartments: (not individual apartments, but for the building managers to handle)

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5. The closest thing I've seen for third-party smarthome integration for home automation is Remotec's ZXT-120 IR blaster for A/C units, which operates off Z-wave for $69 a pop. One user has it successfully running on the Homeseer HA software package:

http://www.amazon.com/Remotec-Z-Wave-ZXT-120-Extender-Conditioners/dp/B00CJBBYS0/

Speaking of automation integration & going back to the MHK1 wireless thermostat unit (#1 above), let's start off with the compaints:

I like my Mitsubishi Mr. Slim ductless A/C and heat unit, but found the remote control limited. Since this thermostat kit was not an option from my installer, I bought this unit. If you search the web, there are very specific instructions on how to take the main unit apart, plug in the wires and then establish communication with the thermostat. You won't find ANY of that info on Mitsubishi's website.

But the thermostat itself is so stupid and rigidly set up to be almost useless as a temperature control device and I find myself going back to the remote control unit, which is more programmable and variable. It, at least, can be set to A/C only, locking off the heat settings.

Note: if, during the thermostat set-up, you tell it that it is a residential install, the programming functions are locked - there is only the one program available, which assumes that you leave the house every weekday morning at 9 and come back every evening at 5. It can not be altered, except to set temperatures for leaving and arrival. This is beyond stupid. Even using it as a "commercial" install, it has limited and rigid time boundaries which are not useful. You must set the heat AND cool parameters for every time period (and there are only 2 time periods per day). My cheap Home Depot aftermarket units (for the radiant floor system in my house) are FAR more versatile and smarter than this unit - except, of course, they won't work with this unit.

So while that's not too positive, there is this tidbit in the reply comments:

The thermostat for the Mitsubishi looks the same as your Honeywell Wi-Fi thermostat that controls your hydronic zone, but they have different internal configurations. You will need a Honeywell Red Link Internet Gateway to connect the MHK1 to the Internet, they cost about $100. The good news is a that once you register the MHK1 with the same account as your other thermostat you will be able to see them together on the same app on your smart phone or computer for remote control. The Red Link Internet Gateway does not use your Wi-Fi, it has its own proprietary wireless connection that is actually much more secure and reliable than your Wi-Fi network. Honeywell designed it for the military and then converted it for use with its home security and thermostat systems. If you have any trouble hooking it up you can contact Mitsubishi or Honeywell Tech support.

Also this:

I strongly recommend getting the Honewell Red Link Internet Gateway which allows you to control this thermostat from anywhere. One note: the online software can't show you the difference between "Completely Off" and "Off but set to activate on schedule". To truly turn it Completely Off from your iPhone, you have to first turn it on Auto, then immediately turn it Off. It's odd, but at least it works.

Only reason for not giving it 5 stars is that I could *not* put this thermostat on a 5-day work-week schedule. On weekdays, I have the unit set to power on in the morning and power off at night. On weekends, though, you have to set an "On" period (the first period cannot be powered off), which I immediately follow 15 minutes later by an "Off" period. So it turns on for 15 minutes on Saturday and Sunday. I contacted Mitsubishi multiple times and they reluctantly agreed that you had to turn it on at least once every day, although advised me I could run it with the temperature in the extremes and the fan off. In this manner, the vents just open and close for 15 minutes each weekend day. Kind of an ugly work around and surprised none of the programmers noticed this obvious flaw.

Since the Mr. Slim units use Honeywell's Redlink wireless technology, they can talk to the Redlink Internet Gateway via Wifi, which can be registered to an online account for temperature control. That guy retails for $85:

http://www.amazon.com/Honeywell-THM6000R1002-Enabled-Internet-Gateway/dp/B006BD1K4A/

My hesitation there is that this is literally the ONLY place I've ever seen this mentioned. And apparently the software isn't exactly perfect, as noted by reviewers...it's not like buying a Nest off the shelf or something.

6. Community development: Tom Konrad created a DIY hack for programming his unit:

http://cleanenergywonk.com/2013/04/...-thermostat-to-mitsubishi-mr-slim-heat-pumps/

There's also been some discussion about wishlisting integration on the Nest forums:

https://community.nest.com/ideas/3103

One guy posted his reverse-engineering results on sniffing M-NET traffic on Github:

https://github.com/LenShustek/M-NET-Sniffer

So anyway, there's a lot of things I like about the system:

1. Can do A/C & heat in one unit
2. Very quiet inside the house
3. Doesn't clog up a window & only requires a 3" opening in the wall
4. Everyone gets their own room temp, and you only are paying for what you're using, not all the ductwork & empty rooms
5. H2i unit can handle reasonably cold winters
6. Redundancy - no central unit to fail

Regarding the Hyper heat system, this was posted in last year in 2014 on one of the Amazon comments:

Mitsubishi does not make a multi-zone Hyper-heat unit yet, but they are coming out with one next year. The unit you have is not hyper heat, which means it probably shuts down completely somewhere between 5 and 10 degrees outdoor temperature. As the outdoor temperature gets colder, your indoor heating requirements get larger, but the output on the heat pump decreases. I would imagine that at 18 degrees outdoor temperature the Mitsubishi is still outputting heat, just not enough to meet the demand necessary to keep the indoor space comfortable.

I honestly don't know why Mitsubishi doesn't put more effort into these, both in marketing & adding features like integrated wifi. It's a genius unit, especially with the H2i feature. Everyone I know who has them loves them! If I ever do get the chance to build a house someday (efficient concrete-wall design), I'd absolutely love to put these into every room (along with a backup heating source like gas, electric, or log fireplaces for when it gets super super cold). There aren't many faults:

1. Big & ugly. Not terrible, but rather conspicuous. Even the ceiling cassette is enormous!
2. No smaller units for smaller areas like a bathroom, which is important if you're not running central air.
3. Lack of off-the-shelf consumer integration technology for home automation

Also I guess lack of advanced features: real dehumidification & humidification, higher-level air filtering, and so on. I don't know how these compare to say an IQAir system or ERV/HRV & whatnot. It's 2015 - it's time for us to get better control with more efficiency. They're starting to make "smartvents" for per-room control, adding more controls for heating, cooling, humidity control, fresh air exchange, air filtering, automation in conjunction window treatments for heat, etc., as well as per-room thermostats (Aeotec's Smartsensor 6, Quirky's Spotter v2, etc.) for getting per-room data. From what I've seen, Mitsubishi has the best mini-split ductless system on the market due to the H2i system, which I've seen successfully operate here in the cold New England winters. I'd love to see more control & integration options, as it doesn't seem heavily developed in its current state right now.
 
Nice, can you set the faucet water temp separately from the boiler for room heat?

yes and no, it depends on how its setup

our hot water does still get super hot but they changed something down there next to it to make it more adjustable and separate from the baseboard heat
 
Can you elaborate more on the interface system?

As to specifics, no I can't.
You really need to contact MitsubishiComfort for that.

As I mentioned above the systems were zoned, could be controlled individually or from a central control.
Some outdoor units had multiple indoor, independently controlled units.
Thermostats were both wired and wireless remote (linked).

You may be right that these were commercial units installed in a residential application.
My concern was budget and that the customer was happy (which they were).
It was an unusual item for us, as we normally have no more that 2-3 zones run by a separate std. central air unit for each zone.
The Mitsubishi units were used because the clients wanted 4-10 zones in the same house (each bedroom separate + other separate living areas in large homes) and were willing to pay what it cost. 😉

We had a MitsubishiComfort Diamond Contractor do the design and install after having the customer sign off on the cost. Both were 2 and 3 yrs. ago, and we've had no call-backs or warranty from either.

I've talked regularly to both clients and they are very happy with the functioning of the units and zoning.
Apparently one couple likes their bedroom @ 60F, and the media room @ 70F, with other common areas @ 75F.
(BTW - We are in FL)
 
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