Professional Member*
Ok. This thread has me all messed up. The OP hasn't communicated the issue well. It first sounded like a RV issue now it's sounds like a control wiring issue.
To the OP, HVAC 101. Check all the basics. Test low voltage. Confirm low voltage in correct areas. Confirm high voltage in correct areas. Ohm out all pressure switches and sensors. Connect your gauges when you first arrive and don't take them off the system until your finished.
Once you do this, coupled with advice already given; The problem should become pretty apparent.
Professional Member
Just to let you all know I did all the checks and balances and it wound up being the circuit board. I guess it was intermitent and screwed the pooch when it decided it wanted to. HO is pleased because it was under warranty, I am pleased because it is over. I have little expeirience with circuit boards and some of us are still learning. So for those of you that want to act like they know it all, you dont and nobody does!
Professional Member*
Jeffrey,
Great to hear that you found the problem!
Learning. That's what this site is for. I learn something new on here almost daily. Example: Rundawg schooled me on a timed defrost issue just a few days ago.
From what I read, I don't think anyone was acting as if they "know it all" and I certainly hope that I wasn't the one who came off like this.
We are just a group of guys who are passionate about HVAC and volunteer their time in an attempt to help out/receive help from others. We can only help others if the correct information is relied to us. I hope you didn't get discouraged by my comments or someone else's because we need guys like you around here!
Good luck!
Professional Member*
I suspected the internal time delay on the board, but you need to verify power coming to the board thru the Y wire, and then verify the Y power leaving the board and going thru the pressure switches to the contacter. That would have showed the problem was the board. As you work with these units, it will come easier. Just working on a few of them over time will make you feel less intimidated. Take the time (when you have it) to play with a few things in the controls, and see how they react. At the very most, you may blow a control fuse, but you'll gain an understanding of what the different components do, and how the equipment acts when they don't do what they're supposed to. Make sense???
One way to outthink people is to make them think you think. They'll think you're not really thinking what you're trying to get them to think you think...........
AOP Committee/Professional Member*
I'm sorry, I must have missed a post where someone was "acting like they know it all."Originally Posted by jeffrey43
1) keep learning
2) improve your attitude
[Avatar photo from a Florida training accident. Everyone walked away.]
2 Tim 3:16-17
RSES CMS, HVAC Electrical Specialist
Member, IAEI
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AOP Committee/Professional Member*
Okay. So this is a residential install.
Riddle me this, Batman.
Why is this post in the Tech to Tech COMMERCIAL forum???
[Avatar photo from a Florida training accident. Everyone walked away.]
2 Tim 3:16-17
RSES CMS, HVAC Electrical Specialist
Member, IAEI
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Professional Member
I wouldn't think the board was the problem if the contactor was pulled in and the fan and compressor were not running. Sounds like the capactor might be going bad.
AOP Committee/Professional Member*
Sounds like he needs to sit down with his boss and go over diagnostic skills.
[Avatar photo from a Florida training accident. Everyone walked away.]
2 Tim 3:16-17
RSES CMS, HVAC Electrical Specialist
Member, IAEI
AOP Forum Rules:
Professional Member*
Hahahaha...This thread just keeps getting better.
With how the OP described the problem I would never have been able to diagnose it.
A reversing valve needs a differential pressure to shift. If you can't make this happen it won't shift.
Glad you figured it out.
Also, hope it's not low on charge when it's time for cooling.
Regular Guest
When you say the compressor starts for a second then shuts down, I am assuming the contactor is not opening and the compressor is going out on thermal. This combined with the info that you are checking the charge in cooling mode and the only value we know is 8 degrees subcooling makes me wonder if the system may not be charged correctly.
You stated there is no TXV so when you are checking pressures in cooling mode we need to know superheat, however, the more accurate method to check the charge would be to look at the manufacturer winter charging chart which should be with the unit unless the installer didn't leave it there.
I have seen reversing valves shift with no noise, and, keep in mind refrigerant flow is what causes it to shift, so the unit must be running for the shift to take place.
If the compressor is out on thermal it may take several hours to cool enough to start
Good luck
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