Help choosing a new boiler (part 2)

Heat pump water heaters need a fair amount of space around them to pull heat from. They discharge around 43F air into the space you locate then. Read through an installation manual to be sure your home is a good candidate.

I have had great success with 6 different combis that I have owned, dating back to the MZ Monitor of the early 1990s Endless hot water at a 2 gpm flow rate with a 120k and the boiler can be derate to exactly match your heating load. Outdoor reset is standard. Lochinvar, IBC and NTI are well known brands in your area. Normally every 2 years is a good maintenance schedule. This would be true of any mod con boiler, combi or not.

There are good hydronic contractors in your area also.

Navien NHB-80H is not a combi

Navien NCB-80H is the combi. Both have heat exchangers designed for hot water and are the poorest heat exchangers I have ever dealt with.

lochinvar- I have done plenty of noble combi's and consider them one of the best. epic is a step down so a small increase in the price its worth it for the noble

IBC- No installs or service.

the reason the Navien sucks is because its mainly an on demand water heater that is reconfigured with a flat plate heat exchanger for heat. So the main heat exchanger which is really junk is not ASME rated or even in the ballpark as far as quality. its a kiturami piece of crap and because the domestic hot water runs thru it you will have to descale it quite often.

we deal with Naviens all the time because we service multiple chain restaurants and they are space savers. You don't pay rent for a mechanical room because you don't need one. They put these in the kitchen anywhere. above the walk-ins, on a common wall, above the rear entrance, etc.

this is the rep for Lochinvar across most of Canada. Contact them for a list of contractors that are factory trained. My experience is that this is a very good rep firm. They support the contractor with training and repair parts.

https://aquatech-canada.com/about/

NTI is a Canadian brand out of Saint John, NB, another solid choice with a good team.

IBC is also a Canadian company

@hot_rod 's advice is sound. I would check out the Lochinvar Rep to find a contractor in your area.

There are three things I would consider when purchasing a heating system.

• How long do you expect to live in that home
• The return on investment on the product you choose (in energy savings)
• What the life expectancy is on the equipment you choose. 

For example, you plan on living there for 3 to 5 years.   Get the lowest cost equipment available because you won't be there long enough to realise the savings on the higher proceed higher efficiency equipment.

Another example, If you plan on living there for 10 to 15 years.  Get a higher efficiency system.  That is where the sweet spot is for most “return on investment” numbers that fall into the good investment time frame.   Those higher efficient boilers also have  shorter lifespans,  like 15 to 20 years.  So by the time you are ready to leave the home, you have recouped the savings and you will be bone before you need a replacement boiler.  

If however you plan on finishing your life in that home, and you are in your mid 60s, then you want a  boiler that has the longest lifespan.  They seem to be the lower cost Cast Iron boilers that have the least amount of bells and whistles.   They are not the most efficient systems, but you will not be purchasing a new boiler when you are in your late 80s when you are more susceptible to being taken advantage of.   

So there you have it.  The choice should be based on your lifestyle and your present and future plans with that home.

Lochinvar has a good product and they have good support for the contractors that install them.  They don't make the Cast Iron boilers that Weil McLain, Peerless, Crown or Burnham make. Their lowest price point boiler is the Solution series that has a copper tube heat exchanger that operates at about 84% efficiency.  

The Knight series is the higher efficiency condensing boiler and it also have good reviews.  The efficiency is at about 95% 

If you want the longest lasting boiler then you want to look at the other brands that sell the cast iron boilers.  The lowest cost boilers have the least amount of parts to fail.  And the cast iron sections can last over 40 years when well cared for.  Weil McLain CG boilers are a real workhorse as is the Crown Aruba series 5 boiler that checks in at about 84% efficiency.

As far as indirect water heaters are concerned, I believe they are the best way to make Domestic Hot Water (DHW).  Tankless do not last as long and you may need to sacrifice the way you use hot water.  A 199,000 BTU tankless will cost less to operate in the long run but it will need to be replaced every 9 to 12 years in my experience.  You may not be able to use the washing machine and the dish washer and take a shower at the same time.  And if you have two showers going on at the same time, well that ain’t gonna happen with a tankless.   

The indirect tank will last over 25 years in my experience.  Some models have a lifetime warranty.  Compare that to a tank type gas water heater that is connected to a vent to exhaust the fumes from burning gas.   That vent does not go away when the gas is turned off when the tank reaches temperature.  That vent is connected to the outside the entire time that the water heater is not burning fuel.  It is like a vacuum cleaner sucking cooler boiler room air through the vent, picking up heat from the hot water tank and exhausting it outside. The vent type tank may need to recover every 4 to 5 hours even if no one is using any hot water. Your energy is literally going up the chimney.  Finally the tank type water heater burner is about 40,000 BTUs and is about 78% efficient 

An indirect uses the larger house heating burner so the recovery will be much faster, that means that you can take 2 showers at the same time without running out of hot water.  Next is that the tank is not connected to a vent. So when the tank is satisfied and the burner turns off, the heat in the tank will stay in the tank up to 3 times longer before it calls for heat again. If no one uses hot water for 15 hours, then the burner will not need to turn on to recover that temperature drop the vented water heater experiences.  The burner that runs your heater is at least 84% efficient or as much as 96% efficient.  (more efficient than the tnk type 78% efficient burner.)  the vent is connected to the home heater amd that can cool off without wasting the heat in the water tank.  So you don't need to keep the house heating boiler hot all summer.  You only run the more efficient boiler when you need DHW.  You don't keep the boiler on all summer.    

Those that don't recommend indirect water heaters have that misconception that your house boiler is at 180° all day long 24/7 all summer.  That is simply not true. 

I hope this finds you some additional information that you can use to make an informed decision on your new boiler and water heater

I don't think that you should worry much about the modulation BTU output. its going to about 4' of baseboard difference. I think you should concern yourself with getting the best installer you can find. the installer is the most important part of the install. If you follow some of the threads on here you can read about all the improper installs. They are continuing headaches for the homeowners. And the contractors just turn around and blame the manufacturer. Its like a never ending story. I had one service call where the customer complained to me that she saw the contractor more than she saw her husband.

@RandomLady , this is not Rocket Surgery. 40 years ago, I took a class from Dan Holohan (The guy who started this website) and from that day on, I would do a heat loss calculation. I measured the walls, windows, ceilings, floors, and doors. Put all those measurements on a form, used the appropriate multipliers and came up with a number. It was often 50% or more lower than the old heater that I was replacing. This was impressive to my customers because none of my competitors did that. I also guaranteed that the smaller heater would do the job or I would install the larger one at no additional charge. That is how I grew my business.

The heat load calculation was not the most accurate calculation by design,  It was a short form sheet of paper and I used the next lower multiplier just to be sure it was a little oversized. But it was enough for me to know that the selected size was not too small. Granted I may have still been a little over sized but I would rather it be a little over sized than it be undersized. The smaller heater still was a better choice than using the same size as the old one, my competitors quoted.   Once computers became popular, I got more accurate numbers.  

With the new modulating boilers, you don't need to be as accurate. If your home needs 81,254 BTU per hour on the coldest day of the year and you select a 120,000 BTUh heater that modulates, then that oversized heater will only be an 81,254 BTUh heater on the coldest day of the year. That is the way they work. So the oversized heater is not really oversized at all.  The fact that one model will go as low as 8,000 BTU and another will go as low as 10,000 BTU is nit picking in my opinion.  All that means is that your boiler can’t modulate when the outside temperature is above 59°F or 57°F (15°C or 14°C) so it will just cycle on and off when it is 16° or warmer outside, if you even have the heater on when it’s that warm.  You did pick Ontario Canada to live in… 

For my retirement I choose to go south.  I digress

I would not stress over the low end of the turndown ratio.  If you happen to select the lower one because the contractor is the better choice in your opinion, then good for you.  If you believe the other contractor is the better choice then go with the better contractor.   Look at the reviews online to see if they offer better service after the sale.   Get recommendations from friends.  The contractor that stands behind the equipment they sell is always the better choice.  The brand of equipment is secondary to your choice. 

A final note: when I taught my one day seminar on Hydronic heating to professionals, I would often mention that selecting the proper size boiler based on the heat loss of the home may oftentimes render the boiler too small for the DHW demand of the homeowner. In this case you should select the size based on the DHW demand even though it may be oversized for the home’s heating requirements.  With the modulating boilers that makes more sense now than before because the oversized boiler will adjust down to the correct size when not being used for DHW.  Just don't go overboard with a 199,000 boiler when your load is only 50,000 BTUh.   That is just wasteful ignorance on the part of the contractor.

I’m sorry, but I have to strongly disagree with this. An indirect water heater is an extremely simple device, as simple as an electric water heater, maybe more so.

An electric water heater has two thermostats, two heating elements, and a limit switch. An indirect simply has one hot water coil, which is heated by the boiler, submerged in the tank, plus an aquastat or sensor to control the temperature. Electric water heater elements and thermostats have to be replaced quite often, but an indirect usually lasts 20+ years with no repairs required.

The electric elements in an electric heater can only produce 15.3k btus to heat the water. An indirect will have the full 85k btus of your boiler to heat the tank. Hence, the indirect will recover more than five times faster.

An electric heater uses electric resistance heaters which cost about three times as much to operate as heat produced from natural gas.

Mod/con boilers come already setup for indirect water heaters, the only additional component which is sometimes required is an additional circulator, depending upon the model.

The only positive side to an electric is that it initially cost less, but if a new electric circuit is required, that may more than offset that.

Don't get estimates on any combi boilers.

Just one old man's opinion

At days end, under the hood , many mod cons share the same parts . Heat exchanger , gas valves, inducer fans. Control features vary from price point brands to the more expensive models

In 20 years from now repair parts may be non existent. Like all major appliances.

Please let us know how it turns out. Post some pics, too.