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Opinions WeilMcLain GV90 Series Boilers?

Newtothis Member Posts: 12
Its been almost 5 years since I was on here last time. I successfully upgraded my last house to natural gas.

Now I'm doing it again on a new house. I'd like to get an efficient boiler without all of the computerized stuff that the 98% efficient that can go wrong.

Here are my reasons for liking this series:
-Cast Iron Boiler
-Less complicated than computerized SS heat exchanger. Doing the install my self I will not have manufacturers warranty to cover complicated circuit boards that are prone to fail on top efficiency models.
-Direct Vent and exhaust side discharge from house
-Price is pretty good

Further Questions:
-Anyone know anything about reliability of these?
-Any other line of boilers I should consider?
-What pitfalls should I avoid?


  • Rich_49
    Rich_49 Member Posts: 2,692
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • SuperJ
    SuperJ Member Posts: 605
    edited March 2019
    IMHO, the GV90 is more complicated than some of the basic Modcons, due to its internal pump and need to protect itself from condensation.

    My opinion is you should either go traditional cast iron(with some sort of boiler protection strategy).
    Or modcon, simple ones like the IBC HC series don't have much to go wrong, and the controls are simple.
    The GV90 is kinda like the **** child, of a cast iron and modcon boiler, I don't think the advantages outweigh the additional complexity.

    In your case it sounds like a good cast iron boiler might be the way to go, but don't forget a boiler protection strategy, it can be as simple as a thermostatic valve to recirc supply into the return to maintain minimum safe temperatures.
  • SuperTech
    SuperTech Member Posts: 1,792
    Please consider an Energy Kinetics boiler. Extremely reliable and efficient design. Very few proprietary parts to worry about. Extremely easy to service and perfect for direct vent applications.
  • Newtothis
    Newtothis Member Posts: 12
    Energy kinetics look interesting. They don' t seem to sell through the normal web dealers. How are they priced? Are we talking $2-4k price range or a giant price jump above these?
  • Newtothis
    Newtothis Member Posts: 12
    @SuperJ can you elaborate on the need to protect the cast Iron? My last house I installed a power vent Burnham cast iron. I never worried about thermostatic shock. Are you referring to return water coming in too cold and cracking the cast Iron?
  • Tom_133
    Tom_133 Member Posts: 821
    I love them

    PROS I am a one man band, so I cant be everywhere and because of that sometimes even my best customers need to call someone else. This boiler has a little more complication to the original but not much so the same heating guys who worked on the older style 20 years ago, can still fix them. I like that they are simple to gas convert and almost no setup with combustion analyzer. I also like how efficient it is, I stopped in on an install the other day (they were moving and needed an inspection) tested the efficiency and its right at 92% that to me is great, at max fire 92% and it always is.
    I understand that you can do better in the right conditions with a mod con. I also like the known longevity of the cast iron.
    Also, at that efficiency even when the boiler is at 180 the flue is 100 degrees or so, making PVC an ok option in my opinion. There are more but overall I am very pleased with this boiler, the Weil McLain version even has outdoor reset as an option. I actually like the way Weil Mclain does their warranty when needed.

    CONS its heavy, its on the floor and takes up space.

    Montpelier Vt
  • SuperJ
    SuperJ Member Posts: 605
    I'm referring to running a cast iron boiler with return temps below 130F for sustained periods. There are corrosive elements in the flue gases that turn to liquid and stay in the boiler, if the boiler isn't kept hot enough and eventually corrode the boiler.

    This is different than thermal shock. Thermal shock happens when a hot boiler see suddenly cold temperatures. Flue gas condensation happens when the boiler takes too long or never warms up to safe operating temperatures during a heating cycle.

    It's often not possible to achieve this without some sort accomodation in the design. Unfortunately main boiler install manuals might say to keep the RWT up, but fail to elaborate. So many people end up doing it after they see some evidence of an abused heat exchanger.

    There are different strategies to deal with it, any effective one has some sort of mechanism to decouple or unclutch the boiler from the load so that it can warm up quickly to a safe operating temperature.
    -mechanical thermostatic mixing valve on the return (cheap and simple, no electronics)
    -electronic mixing valve has a sensor to recirc boiler supply into the return to keep it above a safe minimum. (taco iseries has several that do this and more neat stuff).
    -various pumping arrangements (most of them involve adding an additional pump with some sensors).
  • SuperTech
    SuperTech Member Posts: 1,792
    > @Newtothis said:
    > Energy kinetics look interesting. They don' t seem to sell through the normal web dealers. How are they priced? Are we talking $2-4k price range or a giant price jump above these?

    We don't discuss price here so I can't comment about that. They don't sell through any websites, they only sell through contractors that have been through their factory training in an attempt to minimise having their boilers installed incorrectly. They won't be the your least expensive option, but do you really want the cheapest boiler available?

    Energy kinetics offers condensing and non condensing boilers, I was thinking about one of the non condensing E-Z gas system 2000s for your direct vent application. If reliability, efficiency and ease of service are what you are looking for I believe this would be a great option.
    Erin Holohan Haskell
  • Newtothis
    Newtothis Member Posts: 12
    If I can't do the work myself then its off the list. Where I live you can't get a contractor to walk through the door for basic maintenance for less than $1k. On my first house 900 square feet I was looking to have central air installed with a High Velocity miniduct system with very easy straight runs and the lowest bid I got was $30k.

    I get not wanting to discuss labor rates. They vary so widely and understandably so, but with all the internet wholesalers it is so easy to see how much equipment costs except for these Niche companies like Energy Kinetics.
  • rick in Alaska
    rick in Alaska Member Posts: 1,362
    My personal opinion of the GV boilers are that they have been around a long time, and are proven. I don't understand the complicated part; they just have a bypass pump built in. Otherwise, they are very simple, and reliable. If you go with the GV90+, they take the regular GV boiler and just add an external secondary heat exchanger, which picks up efficiency, and makes it so you can use plastic venting.
  • lchmb
    lchmb Member Posts: 2,997
    I've installed 25 plus in the last two years..make sure to pipe it primary/secondary and I recommend poli venting. For a condensing boiler it's extremely simple and in every case I've seen savings for the customer..
    Pro; very quiet, very efficient, very easy to maintain.
    Con's; heavy, awkward to move, takes up floor space..
  • ice4me
    ice4me Member Posts: 21
    One thing worth noting is that the GV90 isn't a modulating unit (as far as I can tell - I have no direct experience with them). So I wouldn't get too caught up with the efficiency rating, since you are unlikely to be running at design conditions much of the season.

    I looked at this unit during my own boiler selection process and found it hard to justify its cost compared to a true mod/con. I know you are looking to stay away from the complication of mod/con units, but it could be worth a second look for the money. For example, you can buy quite a few spare parts for the HTP UFT, which are all available online direct from HTP, for the price different between this unit and a GV90.

    For what it's worth, I also currently have a Weil-McLain CGa cast iron boiler that I picked up used to tie me over until my mod/con system is up and running. This boiler was 10yrs old when I bought it, so I tore it all apart for inspection. Super simple, very easy to work on, good parts availability, and appears to be really well made. All that to say, from my experience, WM seems to make a nice product.