Jon Klima, Owner
360 Trout Lane, PO Box 23, Guffey, CO 80820
Phone: 719 479-2281,  Email:
In business for 39 years


• Article 5 - December, 1990


Harold Spagatinie and Close E-Nuf Plumbing troubleshooting solution and IE C-30 and DTT-XX series problems you can fix yourself©


The last newsletter discussed a problem dealing with an apparent tempering valve problem that Harold Spagatinie had with his solar DHW system. Three people, Mike Tearney from Aspen Solar, Mike Hellan from Colorado Solar Design, and Charles Hensley from Sierra Mechanical, contacted me with the correct analysis of the problem. Good analyzing, guys. Harold's problem involved hot water from the solar preheater moving through the auxiliary heater tempering valve (only when the circulating pump is on) without any mixing occurring. The problem is caused by the pressure at the discharge side of the circulation pump being higher than the cold water main pressure at the cold water inlet to the tempering valve. In fact, if Harold's system didn't have a check valve in the cold water line leading to the tempering valve, he would have had hot water being pumped into the cold water line when the circulating pump was on. Of course, this would only be noticed when the cold water faucet was opened.


I have a few short tech tips for you this month. I've had controllers sent to me with the following problems that you can fix yourself and save a controls repair or checkout bill. Occasionally, the R-W or freeze sensor jumpers on a C-30 (and others) will not be properly secured under the terminal board screws. This can cause intermittent operation of the output. Always verify that these jumpers are properly secured. Next, I am often asked why the Dynatech SC-30 controller "ON" function does not turn the controller output on. The switch that would normally give a manual ON condition has had the "ON" pin cut off so that you cannot give a manual ON, i.e., it's built that way. The switch can be modified by soldering the pin back on, but is it worth it? The final tip involves the Heliotrope digital controllers (DTT-XXT series). Once in awhile the digital display doesn't switch to a different channel properly. This can be caused by a small amount of dirt/grime on the switch contacts. Get a spray can of TV tuner cleaner from Radio Shack or any other electronics parts store and spray a small bit into the switches at the point where the lever exits the switch. Work the lever back and forth a few times. This may solve the problem.


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