ERV croaked – Part 4

Yes! The saga continues! For one more episode.

We have been living on the 1st floor for a few weeks, but still go frequently down into the garden apartment for laundry, etc. And I began to notice that it got really cold down there – but I thought that was OK since I had turned the heat down.

I also organized a dual probe temperature sensor to measure the ERV performance. I had planned to dedicate a blog post to it. I measured the temperature of the fresh incoming air at 26 F. The temperature of the fresh air leaving the ERV into the building measured 38 F. That is a total heat recovery of 12 F – which is appalling! You can’t even call that heat recovery!

At that point it finally dawned on me that something was wrong: cold apartment, next to no heat recovery in the ERV…

I was back on the phone with the UtlimateAir tech support and learned that they are two probable causes for failure of the heat recovery:

  1. The enthalpy wheel is not turning (as was the case in January and November. But this time, the wheel was running fine.
  2. One of the two blower motors is not working.

And as I found out, the blower motor that exhausts the stale air from the building to the exterior had taken a leave of absence.

To find out what exactly was wrong, tech support guided me through a process of elimination. We started with the fuses on the circuit board that control the blower motor. The fuses were good.

Maybe it’s the electronics on the circuit board? I took the existing circuit board out and replaced it with a spare one. Still, the motor was not running, so it wasn’t the board either. Conclusion: it is the blower motor itself that croaked.

I could tell by the reaction of tech support staff that this doesn’t happen often.

As usual, I promptly got a replacement motor in the mail, and I began to pursue one of my favorite hobbies: opening up the ERV.


To replace the motor, I had to disconnect all the wires, take the circuit board out, and remove the electronics plate.

ERV-16 ERV-17

On the other side of the electronics plate sits the impeller – the fan wheel that actually moves the air. To remove the motor, I have to disconnect the impeller from the motor shaft.

ERV-18 ERV-19

Sounds complicated, but is pretty straight forward. The good news is that after I installed the new motor, everything fit back into place and I had no leftover screws sitting around. The even better news that the new motor is running and we have a functioning ERV again.

This was the third time this winter that the basement ERV gave out on us. Plus the issues with the filter pies that took the 1st floor ERV out of service for about a week. That’s not a remarkable track record.

I wanted to know if this is normal and ask UltimateAir to comment. Here is the statement they kindly provided:

“The UltimateAir team is grateful to Marcus for his patience and understanding. Our engineers are continuously working to not only improve the performance of our technology but also raise the product’s reliability. In the world of specialty boutique manufacturing there are often unforeseen changes in batch supplies of parts that go undetected.

Despite quality control procedures, including incoming parts checks, running every unit 24 hours before shipping and following all UL protocol, issues are not always identified. Marcus’s 200DX ERVs have witnessed a “perfect storm” of issues and does not represent the vast majority of our ERV units. UltimateAir has over 4000 model 200DX ERVs in operation with an overall failure rate around 3%.

We offer a 5 year parts warrantee on all UltimateAir ERV systems to insure that consumers feel secure when making their ventilation purchase. Overall, we realize this has been inconvenient to Marcus and we apologize for the discomfort he has experienced. As Marcus has witnessed the UltimateAir team is always a phone call away and we will back our technology in every way possible.”

Related posts:

About Marcus de la fleur

Marcus is a Registered Landscape Architect with a horticultural degree from the School of Horticulture at the Royal Botanic Gardens, Kew, and a Masters in Landscape Architecture from the University of Sheffield, UK. He developed a landscape based sustainable pilot project at 168 Elm Ave. in 2002, and has expanded his skill set to building science. Starting in 2009, Marcus applied the newly acquired expertise to the deep energy retrofit of his 100+ year old home in Chicago.

9 thoughts on “ERV croaked – Part 4

  1. That was a question the UltimateAir tech support asked too. I don’t think a power surge was the culprit. The ERV has two of those motors, plus the motor that turns the enthalpy wheel. But only one motor croaked. Plus all the circuit boards were in working order. Said said, Ultimate air recommends to have a power surge protector between the ERV and the outlet.

  2. Hi Marcus. I too own an UltimateAir ERV. We started having problems with the unit just a few months after it was installed in our new home in 2012. They eventually sent us a replacement unit. We’re still having problems. I’ve finally decided to look for a replacement from another manufacturer. I’ll be posting our story soon. Thanks for writing about your experience. I was worried it was just us.

  3. Sorry to hear about your problems with the UltimateAir. Our two units have been working fine (knock on wood), since I posted about the problems we had. Please send me a note once you posted your story. Would like to read about it!

  4. Hi Marcus,

    I posed this weekend.

    I linked to your post and took your lead on breaking it into parts. Part 1 is the history. Part 2 will be our retrofit story.

    After the post I received a few more stories of people that have had similar problems.

    We’re going with a Zehnder CA350 retrofit. It is a bit more expensive then the UltimateAir, but cheaper than all the fixes we’ve had to do to keep the UltimateAir working over the years.I’ll ping you when we post part 2.

  5. We had an UltimateAir installed our new Green House built in 2012. Long story short, I’ve had to swap it out three times since, last time September of 2018. Now, again, it’s making horrible noise due I believe to either the small motor in contact with the spinning wheel or bearings on that wheel. Usually the company has been excellent in support (but I’ve paid to ship the beast from Ohio to Santa fe) but two days attempting to speak to tech hasn’t occurred. Not happy and wondering if I should just cut my loses and buy a new unit from their competitors.

  6. Ultimate Air 200DX installed installed 2007. All good until this last winter. Went in on Dec. 2019 , cleaned and resume. May 2020, opened up. Found all pads are wet and BLACK! Wheel not turning. Opened up interior control box and found two foil capacitor blown to pieces and wheel not turning. Tried multiple times to call and email manufacturer. No response. Having it taken out next week and installing Renewaire EV-130. Maybe not as efficient as U.A. unit, but parts and consultation are available. Am kinda ticked that original unit gave no indication that is was sick. Am installing an outside air inlet MERV-8 filter on outside structure wall to prevent contamination of duct work and unit. Am mad that orig. unit gave no outward indication there was a problem.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.