Page 1 of 3 123 LastLast
Results 1 to 13 of 32
  1. #1
    Join Date
    Sep 2006
    Posts
    91
    Could you tell me about the Rheem MOD?
    You mention it alot and I've never seen one so fill me in.

    Love yer handle btw

  2. #2
    Join Date
    Feb 2004
    Location
    chicago suburbs
    Posts
    4,422

  3. #3
    Join Date
    Sep 2006
    Posts
    91
    The sales glossy's are meaningless, I wanna know why as a tech do I like it? I don't see anything that is better than an XV90 here other than the extra stage of gas operation unless I buy their special Tstat.

    And what's w/ the spark ignition? Didn't that go out in the 90's ?

  4. #4
    Join Date
    May 2006
    Location
    Philadelphia, PA
    Posts
    1,391
    Originally posted by stafford
    And what's w/ the spark ignition? Didn't that go out in the 90's ?
    It's making comeback.

  5. #5
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,184
    If you look at it from a techs point of view, stages mean nothing. It's just simple, reliable furnace. Instead of counting flashes, you look at a full digit LED. It has dozens of codes to pinpoint exactly what's going on. We've rarely had problems with it. It's easy to maintain, simple drain system. In 13 years of that heat exchanger being out, we've not had one failure and our supplier says he's never ordered one.

    NOW, from a homeowner's point of view, comfort 2 stage can't touch. When are you more comfortable, with heat on or off? On obviously, especially an inaudible, gentle warmth. Does your car heater have an on/off switch or a simple single stage stat? Or even high/low or a 2 stage stat? Of course not, that wouldnt' be comfortable! It has manual or automatic controls let you or automatically throttle back or increase heat as needed. That's what the Mod does with 13 stages. So in bitter cold weather, the Mod will always be on, like hydronic heat. There won't be the cycles there are with single stage or even 2 stage. The chart compares the Mod with a similar 2 stage furnace. See how the output of the Mod nearly perfectly follows the heat loss of the house. The blower varies to maintain a 50 or 65 degree temp rise so the air isn't cold, even at 40%.


  6. #6
    Join Date
    Sep 2006
    Posts
    91
    Thanks for the reply. That does sound like a nice piece of equipment, and I like your chart too. However, it does sort of seem that like the 2 stage furnace you are using for comparison is a lil' oversized...

    What is the modulating thermostat like?

  7. #7
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,184
    I didn't make the chart but I guess he used that furnace as that's what most people would do given the 75K heat loss he used. I think few would use an 80K input furnace cutting it that close. Of course, since few do manual Js, most probably would put in 120K or 125K

  8. #8
    Join Date
    Apr 2004
    Posts
    7,680
    Sorry I was gone....

    Does the XV90 set itself up for the duct system like the mod does? Can the temperature rise be adjusted manually beyond that to provide additional comofort? Does it offer On demand dehumidification in cooling? Does it have a true variable speed motor or simply two constant CFM's? (Yes I know they call it VS, but the answer is the latter)

    Direct spark iginition is almost flawless. Hot surface ignitors will fail, some last longer than others but direct spark doesnt have anywhere near the same failure rate. Does the other furnace have a capacity reduction down to 40% or can it only got to 60 or 70%? Why with less features does the Trane have to be 6 inches taller?

    Does the Trane unit come with a lifetime replacment warranty if the HX fails? I suspect it has a lifetime HX warranty, which will get you a HX. With the Mod you get a furnace.

    Sorry, it may be a decent furnace but no, it doesnt even belong in the same playing field with the Mod.

  9. #9
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,184
    The XV does have dehumidification on demand plus Comfort R which is just a slow ramp up with a call for cool. They run at 50% speed for the first minute, 80% speed for the next 7.5 minutes then 100% after that. I don't know the answer to the other question on the blower motor. You preset CFM like you do for cooling with the Mod. For each outdoor unit size, you have a choice of 350, 400 or 450 CFM/Ton. Heating you preset your desired CFM as well and the instructions give you an approximate temp rise but there's certainly no supply & return sensors. And we've found them less reliable!

    Customer today was torn between going that way or the Mod. Ended up with A-S XV90, 2 stage A/C, electric furnace and single stage HP for upstairs. That was 4 years ago. So far he's lost the compressor for the heat pump, the ECM fan motor for the 2 stage A/C came wired wrong from the factory and fried upon start up, lost the variable speed inducer this week as well as the main board. Then the board we got from the supplier was DOA.

  10. #10
    Join Date
    Apr 2004
    Posts
    7,680
    comfort R is nothing like ODD. A VS inducer is just asking for trouble. it's a fancy, catchy name but then again, so was "Yugo"

  11. #11
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,184
    The XV80 & 90 has had ODD since their inception. Also Comfort R. I've never used my ODD, the Comfort R and my King HP with TXV coil has kept the humidity plenty low. And you aren'ta kidding about reliability and VS inducers. At least the current model has been more reliable than the previous model with the electronics right on the inducer.

  12. #12
    Join Date
    Sep 2006
    Posts
    91
    Originally posted by docholiday
    Sorry I was gone....

    <snip>
    Sorry, it may be a decent furnace but no, it doesnt even belong in the same playing field with the Mod.
    Hey that's cool, I really didn't know that stuff. I see maybe 3 furnaces a month and they're mostly builder grade. The MOD sounds like a great machine with a lot of flexibility.

    Sort of answers to your questions.

    About the ignition system, I have found the SiN ignitors to be very reliable, I feel you about the SiC ignitors but the SiN's are much more robust. I've never seen one fail.

    Have not had trouble with the inducers either.

    The variable speed drive is the usual GE motor with module on the end like the Loon said. The ODD On Demand Dehumidify? options on board require a call for cool and just slows the fan to 80% when the humidistat breaks on rise. A Tstat solution will adjust the fan speed directly and over cool a bit.

    Lifetime heat exchanger warranty, definatley can't go down to 40%.

    I don't know what you mean about setting itself up for the duct system...

    And Trane can't make a small piece of equipment, we end up dowing alot of low boys b/c of that.

    Thanks for replying...

  13. #13
    Join Date
    Mar 2004
    Posts
    171
    I had an HVAC guy working in my office building yesterday tell me that Rheem/Ruud were the bottom of the line, but better than Goodman. When I told him about the Mod, he did not know what I was talking about, and then he backtracked a little and said his real problem with Rheem/Ruud is their tendency to release new products before training. Everyone has an opinion.

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event