Super nice, super willing to come back and resolve issues. But I'm 0 for 3 on successful repairs on the first attempt. I'll start with the pros first. On the plus side, every time I've experienced an issue Deljo has tried to make it right. That said I hired Deljo 3 times over 3 months for 3 separate items and each time was a disappointment. First time required two visits to fix what was ultimately a pretty basic A/C issue, though I was almost charged an exorbitant amount for the original stated repair (which wouldn't have actually fixed the issue). Second time the boiler cleaning went wrong and resulted in a broken igniter. Third time some HVAC duct improvements were not done sufficiently. Last visit to fix some of the earlier problems ended up causing yet more problems. Now for those who believe the above is bad luck or a problematic customer, read on… We moved into our new home in January 2020. It was built in 1894, and has some older equipment so we expected some issues, but nothing like this. Our first encounter with Deljo… Our main floor Spacepak/Unico A/C unit wasn’t running correctly. I had an A/C tech out to look at an outdoor compressor that would click but not stay on. The tech thought it was a bad contactor, said it would $350 to replace (I found out later this is a $50 part and about 15 minutes of labor mind you) plus $100+ the service call charge. He was pressuring me that I shouldn't try to repair a 27 year old unit and should have the office come quote a new system (which they did at over $10k, btw). He swapped the contactor and the unit was still failing to start. Tried again with another new part and it kept failing. He finally gave up and left. We ended up rescheduling with a different tech who found the issue (a faulty time delay module, which he removed at no cost since it's not necessary with modern thermostats). I chalked up the issue with the first guy as him being inexperienced since the second guy who came out seemed incredibly knowledgeable. Our second encounter… We hired Deljo to add returns to our attic HVAC unit. That disaster of an install was done by the prior owner and is oversized and poorly ducted. The salesman who walked through the issues with me in the house seemed to understand what I wanted. I provided a marked up photo to help explain. We both recognized the existing unit is oversized, but there was maybe 500-600CFM of return air for a unit moving 1400 CFM/100k BTU, so additional duct work was going to be needed regardless as even a unit half the size would need more airflow. I suggested to the tech that I’d built a chase in the adjoining room and they would need to run maybe a 12x18 or two 12" return ducts. Deljo quotes $2227 for the work and says 1.5 days to complete. When the tech arrived he disagreed and said two 12” returns would be 1200CFM - "too much return air". Later that morning he says he wants to string flex returns through a closet instead of the chase which runs to the attic because it’s too far and the CFM loss is too great. I tell him we can’t do that because we need to go through the closet to access the unit to change the filter. Ultimately he ends up adding 400-500 CFM of flex duct to the existing duct-o-pus with a couple 8" runs, but then runs out of time and can't finish the first day, so he leaves and tells me the office will call to reschedule the rest of the work. I don't hear from the office for 24 hours so I call back to schedule. They aren't able to make it back out until the end of the week. Our third encounter… Meanwhile later that week I had already scheduled a boiler cleaning for the downstairs heat. The tech arrives on Thursday, spends an hour checking out the unit and cleaning it, then tells me the igniter wire broke when he was pulling the burners out to clean them. The unit is close to 30 years old so I understand things can happen. He uses electrical tape to repair it (which melts and smells) but says it's OK to use until they can get me a new part. The office calls me on Friday evening to schedule for a week later (the following Friday). Back to our second encounter, part two… The following week the same installer arrives to finish the job. He strings the rest of the flex duct and then turned down the gas pressure on the unit. I asked him if 25’ runs of flex duct are OK (they are not code) and if they should be sagging and sitting on top of each other. He tells me they are fine. The heat fires up and runs for about 10 to 15 minutes and then he declares victory and leaves. About 30 minutes later the unit shuts off. The error code is 3 flashes. The unit won’t come back on. I spend two days reaching back out to the salesman and calling the office multiple times before they schedule someone else to come out. Keep in mind the heat has been broken the entire time. Thankfully we have a boiler downstairs so the 3rd floor just leaches heat rising up from the lower floors, with electric heaters filling the gap. The second and third encounters, revisited… After the multiple calls, another tech comes out and examines the upstairs unit. Of course by now with cycling it on and off the 3 flashes are gone and the issue won’t repeat for him. He checks the drain, pressure valve, etc but all seems good. He turns the gas pressure up a bit since the prior installer set it lower than the manual permits. He says he thinks the wind may have tripped the pressure sensor. So far the heat it still running after 24 hours. The same tech brings the repair part for the igniter wire that was broken during cleaning. The repair is pretty fast, but a couple hours after he leaves I notice the smell of burned rubber. I check the brand new igniter and find the rubber boot on it has melted. I’m pretty sure this isn’t supposed to happen. At this point I’m just going to order a spare igniter for $35 from Amazon so when this one breaks I’ll have a replacement I can swap in. Results of the second encounter… Measuring all the returns and supplies in my house my anemometer confirms it's pulling about 950-1000 CFM, which is still not enough airflow for a unit of this size. Yes it’s oversized for the space, I know, but the point of this was to get us to a usable state, which would have worked if he didn’t use undersized flex ducts for the additional returns. I started with about 500-600 and I’m now at 1000 (as measured by an anemometer), well short of the roughly 1400 CFM required to run the heat and A/C properly. If the installer had used 12” duct like I requested we would have easily been above 1400 CFM now. Instead he used 8” flex duct which still leaves the unit struggling to draw enough air through the considerably smaller diameter and higher resistance flex duct. The end result is that with the gas pressure reduced the unit isn't shutting down from over-firing now, but after some brief testing there is still not enough airflow across the A/C coil to prevent freezing up. Follow-up. Given the insufficient air flow on the 3rd floor, I completely gutted the flex duct and bought sheet metal and hard duct from Menards. Another $1500 in parts for me plus considerable labor, but after a week of effort I now have a correctly functioning system. Air flow as measured with the anemometer is roughly 1350 CFM and the total system pressure is 0.55" w.c. Despite what the duct installer claimed, two 12" ducts plus one 8" duct was actually just the right amount of return air. Final thoughts on the saga… I really want to like Deljo. Their Angleslist reviews were good, their front line customer service folks are friendly, and when you do get a knowledgeable technician they are good. But there are too many folks working for the company with seemingly little experience or knowledge that I cannot recommend them. And after spending over $2000 for work that I ultimately had to scrap because it didn't work, I would not use them again or recommend them.