White Vinegar would probably do just as good a job...
And I worry about chlorine touching galvanized metal... which often the overflow pan is...

I got the 608 universal license. It was some work but it didn't cost much money. I took the test at a Johnstone dealer. I studied the material for about three weeks. YMMV, I do well on tests.

Develop good rapport with a dealer to get the prices on future purchases.

You will get more useful knowledge from the textbook approach than from certification.

I bought a couple used recovery machines for $50 each.

thanks for all the good info and keep it comming!

the hvac guys in my area charge a minumum of $70 for a 1/2 hour visit.

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1993 Mercedes Benz 300D 2.5 205K (ex wife's)
1984 Mercedes Benz 300SD 320K (SOLD)
2004 Mercedes Benz C240 75K
1995 GMC Sierra 2WD 5.7L 188K
1983 Mercedes Benz 300SD 239K (SOLD)
1987 BMW 325i 220K (SOLD FOR SALVAGE)

609 Certification

Had to repair the 17 year old Goodman heat-pump at Mom's Virginia Beach house after Hurricane Isabel. Condenser fan died. Not sure if this was hurricane related or just coincidence. Anyway, the wire splice inside the motor burned up and took out the defrost timer circuit board. The motor relay was still working but looked pretty fried so I replaced it along with the motor capacitor. The motor, capacitor and relay were generic parts so I was able to get new ones without too much diffculty. Unfortunately, Goodman is not a popular brand in Tidewater Virginia so finding the defrost board was a challenge, involving finding a number to call Goodman in Houston for help in finding a Virginia parts vendor, then getting a vendor to actually sell the part to me. One vendor refused to sell, or even give me a price, because I'm not a licensed HVAC contractor! Eventually found a vendor in Norfolk that did (reluctantly) agree to sell me the defrost board.
Total parts cost was $190. (I figure at least triple that to have a tech come out to fix it, if they didn't try to sell me a new heatpump first)

Since the repairs, it's worked perfectly heating and cooling last year and so far, this summer, it's still working fine.

Happy Motoring, Mark

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DrDKW

I recently had to do a repair on a roof AC on an RV. The unit quit blowing cold air. I checked the electrics and determined that the compressor was running. I had to add service ports to determine pressures. I prefer Robinair line taps and installed them on vertical runs of line to minimize the amount of oil loss. I measured zero pressure in the system. I hooked up the R22 bottle to check the line taps and see if they were actually working, they were. I found a small amount of oil on the outside of the lines and on closer inspection and removal of insulating foam found where two lines had been touching and eroded each other. Soap bubbles confirmed a leak at that point. I cleaned and soldered the leak. I pressurized the system slightly to check my patch with bubbles and found no leak. I pulled a vacuum and recharged the system. While the vacuum pump was running I cleaned the condenser coils. I did not have access to adequate temperature gauges or charging information so I had to "wing it". I charged the system until the whole surface of the evaporator was producing condensation. The system has been performing well for a couple weeks since the repair.

This is the short story and there are many other considerations that went into this simple repair.

06/15/2006 - System is still working great and is very appreciated.