Discussion in 'Maintenance and Troubleshooting' started by DavidCraig, May 3, 2014.
Does anybody know of any good forums for folks who repair heatpumps?
Probably HVAC-Talk but I can't stand the attitude of that site.
What's wrong with this one?
Come on Dave. Joe is right buy the time you get to geo you can and have fixed anything.
What do you want to know?
Nothing wrong with this forum. What I need is to learn to service the equipment myself.
It is clear that I need to service my own installations. I am a small installer, not a refrigeration man. I hoped that it would not be necessary to mess with the 'black box' - - - Mon Dieu! ... heat pumps have been made for decades and should be like tanks that last for 15-30 years. If they are no longer made that way, there is no way that Geothermal can succeed in spreading to the masses - it will remain an esoteric 'hobby' for people that have money to waste. This forum, and all involved with this type of heating, should be concerned that these systems are built and installed soundly.
My problem specifically has been reported here http://www.geoexchange.org/forum/threads/problem-with-hww036-puttering-out.5841/
Since I'm out the $$$ with a lemon that no one can fix ... that leaves me with the task.
The request for a good refrigeration forum is that I need to learn to replace TXV's ... and whatever else may go bad. It isn't trivial. I've never braized. I've soldered copper for decades, but not brazed. Then there is doing properly without frying the components. And doing so without building junk inside the tube that will clog things. And then there is getting a license to legally handle refrigerant. This goes beyond casual questions on this forum ... although I value you your help if you wish to still assist.
If I sound angry, it is because I am. Two things held me back from Geothermal in the first place: initial cost and reliability of the 'furnace'. Well, I've been bitten badly and have lost my joyful outlook with this kind of system. I've dropped pursuing further installations. And cannot in all honesty recommend that anyone install geothermal - not until the customer can be truly reassured that it will work without hassle ... and not until installers can make a living and sleep at night. I reallize that some of you are doing well and hope that success spreads. But now I simply have to dig myself out of a hole that I'm in - a hole that has nothing to do with my installation but rather a heatpump that the manufacture won't stand behind.
Well, there is always YouTube ...
You tube is a good resource. Smith makes a set of torch tips for refrigeration brazing that are bad @$&.
Here are a few questions that I'd ask such a forum:
What is the typical labor cost for replacing a TXV and filter?
I've been told it is a 4 hour job, so about $300
How do you establish nitrogen flow for brazing in a [soon-to-be] closed system?
As the last joint is finishing, pressure would build and interfere with the brazing. So would you input nitrogen at the connection at the output (compression) of the compressor and remove the schrader at the evaporator end?
Is there a way to evaluate why a TXV failed?
Are there people you can recommend for servicing a heatpump (TXV and filter change) in the Saratoga Springs region?
Labor, service call or trip charge, nitrogen, braze rod, refrigerant, filterdrier, insulation........you are probably 1/2 right.
Thanks. I provided the refrigerant and the factory provided TXV and filter. So $450-500 seems 'reasonable'.
Is it customary to remove the top of the TXV (bulb part) before brazing?
Since vapor pressure is a product of temperature, can you use temperature meters instead of 'gauges' to measure performance? While this would be off a few psi, it should match and has with my observation. It doesn't factor in superheat or supercool, depending on where you place the sensors - however, the digital meters I've seen use a temp sensor to report supercool or superheat (depending on placement).
Are there any suppliers of repair equipment that anyone would recommend as good quality? (A PM response would remove concerns of conflict of interest if that is a problem)
This is a list I've started:
Recovery pump with tank
Brazing torch (acetylene tank + regulator + torch)
Brazing rod (15% silver ???)
Nitrogen tank with regulator (is a flow meter needed as well? or can you 'guess' - see earlier post)
Thermal grease (for temp sensors and bulb) (have)
Dual temp meter (have)
Separate names with a comma.