2003 Carrier Puron 38SYG Heat Pump - Startup & Full Defrost Cycle (Steam Show)

[@ClimateForceHVAC713]

nice defrost man! love these puron units!

[@dilchproductions]

Thanks! Same, they're cool units

[@EthanHurley-ky4hi]

I just noticed you hit 600 subs so congrats!

[@dilchproductions]

Thanks!

[@SamsAirConditioners]

Awesome!

[@dilchproductions]

Thanks!

[@CubeComputerChannel]

Something's definitely wrong. Could be a bad defrost thermostat. If it's stuck closed all the time, this unit will go into defrost even in cooling mode. When that happens, it will just shut off the fan and activate the heat strips (even though there's a call for cooling), and probably trip out on high head since it'll be hot out. Definitely worth alerting them to this problem.

[@dilchproductions]

Yeah it definitely shouldn't have stayed in defrost for that long. My guess is the defrost thermostat failed to open when the coil reached temperature. If that's the case, then are you sure it would try to defrost in cool mode too? I would think the defrost is disabled by the control board in cooling mode since there's no need for it. I will go there this summer and observe it in cool mode.

[@CubeComputerChannel]

@@dilchproductions The logic on many of these timed defrost boards does not monitor the status of the O pin to determine whether or not it's in heat or cool. This is because when the defrost thermostat is functioning properly, it will only close when the system is heating. All the board does is monitor the status of the Y pin, and defrost thermostat. On some boards, the defrost thermostat acts as the power switch to the defrost logic chip. If this thermostat fails closed, the board will accumulate runtime and once 30/60/90 minutes is reached, it will "go into defrost" no matter the temperature of the coil. In the event this happens during cooling, the fan will shut off, and W2 will be energized to fire up the heat strips. Since the reversing valve is already energized, it won't shift. The unit will then trip out on high head since the outdoor coil will get hot rapidly due to the fan not running. This is legit something that can happen! Here's a video of a service call where a tech encounters this exact problem. He was a little confused on how to describe it, so I left a comment on his video outlining what happened. kzbin.info/www/bejne/pn2skohtgMd5jrc Here's a video of a different tech troubleshooting a heat pump running defrost in cooling. kzbin.info/www/bejne/immaaX9qi9eIopo Here's a video of where I am critical of time-temp defrost. kzbin.info/www/bejne/jKK9kJKHid2olac

[@dilchproductions]

@@CubeComputerChannel Ah okay, thanks for the explanation. That makes more sense. It seems like companies should make the control boards disable the defrost cycle in cooling mode to avoid that issue. I do agree that time-temperature defrost is inefficient and causes unnecessary defrosts, but from an HVAC enthusiast standpoint, I like it because it makes it easier to catch heat pumps defrosting. Lol

[@CubeComputerChannel]

@@dilchproductions Honestly, I think TT defrost needs to go. As an computer/electrical engineer, the cost of the electronics to implement the demand defrost logic would cost only slightly more than that of TT. The boards that Rheem/Ruud use are not super sophisticated. Emerson makes them. I retrofitted my system with the Emerson 47D01U-843 universal defrost control. It offers timed or demand defrost, along with an aux heat lockout thermostat, brownout & short cycle protection, pressure switch monitoring, and fault monitoring. It costs the same as some replacement OEM timed defrost boards. I'm surprised the government hasn't forced the manufacturers using TT to move to demand for energy efficiency. Yes, it's harder to catch defrost on demand systems, but oftentimes when you do catch it, it's a steamshow since the coil is full of frost.

[@dilchproductions]

@@CubeComputerChannel yeah I've seen your setup on your unit. Pretty cool, it seems to work well

[@ArisBuliteanu]

Also, it sounded weird during the defrost cycle

[@ArisBuliteanu]

If this unit were to have r410a refrigerant, I would be surprised if a compressor pressure reached 625 psi to open the internal relief valve, if it has one

[@EthanHurley-ky4hi]

Guess what Dilch Productions I'm gonna be posting my first video on KZbin next week! Edit: I'm Ethan Hurley I just changed my channel name too HVAC Ethan cause of the fact that I'm gonna post HVAC videos starting next week and I'm gonna change the profile picture too a picture of our air conditioner tomorrow

[@dilchproductions]

Great! Looking forward to it!

[@ArisBuliteanu]

Why did it shut off three times? Did it met the temperature demand? If it were to run constantly and defrost cycle, I want to see the compressor on a very high-pressure.

[@dilchproductions]

Yes, it kept meeting the temperature demand

[@ArisBuliteanu]

@@dilchproductions like I said, if they were to set the temperature on the thermostat higher, it should’ve had to run constantly, and I want to hear the compressor at a slightly higher pressure than what was expected

[@dilchproductions]

I don't have any control over the thermostats.

[@ArisBuliteanu]

Around 400 psi