The appliance is RHEEM "Rheemgas Quick Recovery Gas Outdoor Water Heater" 120810 BD. I've had this unit since I bought my house 12 years ago and would have been installed way before that. So it had been quite reliable.
SYMPTOMS
- The pilot light could be ignited, but will not stay lit- Without the pilot light the water heating would not operate
- The resulting cold shower and unhappy household :(
Note: Thanks to Josh's Gas and Plumbing for putting up a really useful blog. He even helped me out with my questions although I was not his customer (he's in Adelaide)! Thanks mate you're a legend!
INVESTIGATION
** DISCLAIMER: If you are not a qualified person stop here. Working with gas system is dangerous and potentially deadly ***
The gas control valve and burner is a simple assembly and could be taken of as a whole.
Shut off the gas supply, unscrew the connection to the gas control valve (use 2 wrenches to avoid ruining the copper pipe). Unscrew the burner connection and top bolt securing the plastic cover:
To remove the control system from the unit, pull up the tab and wiggle. The whole unit should come off easily. Do not force:
The system is quite simple but all components must function properly to ensure safe operation (ie. no explosions due to escaping gas). It is a EUROSIT 630 Natural Gas (65 deg C). It is available on Ebay or Reece Plumbing (product code 1318767, supplier code 079421):
- Pilot light valve
Inspect that the tiny hole is clear. Mine only put out a tiny flame due to years of operation. So I sprayed it with carburetter cleaner while at it. - Ignition
Ensure that you can see sparks when the ignition is pressed. Do not touch parts of it while doing this to avoid electrocution! - Thermocouple
This is a neat safety device. When heated it will produce a small amount of electricity (20millivolts) which activates a valve in the control unit. Hence no flame = no escaped unburnt gas. Genius!
In my case I could see spark and the pilot light can be lit - just not stay on so I know that the ignition and pilot valve is ok. That leaves the Thermocouple or the Gas Control Valve Unit
To test the Thermocouple I heated the tip on a stove and observe the temperature. As it heats up it should be increasing steadily from 0 to about 20millivolt. But in my case the reading was quite erratic and sometimes keeping at 0 volts. so I know that it is faulty:
(similar youtube video: https://www.youtube.com/watch?v=Y4izohPW3K8)
I went to Reece Plumbing and bought the Thermocouple (Product code 1317238 - Rheem/Vulcan Thermocouple F/Loader N/Gas) for $48. I tested the new Thermocouple on the stove as above and sure enough the voltage climbed very steadily from 0v to about 21millivolts. Perfect!
The new Thermocouple is a bit longer than the original one, so I had to bend about the copper tube around a bit as shown on the 4th photo above.
I installed everything back, and tested the pilot light. Now it stays on! As a final step I did leak test on the pipe using soapy water. Then a nice hot shower afterwards :)
THE PROBLEM & SOLUTION
To test the Thermocouple I heated the tip on a stove and observe the temperature. As it heats up it should be increasing steadily from 0 to about 20millivolt. But in my case the reading was quite erratic and sometimes keeping at 0 volts. so I know that it is faulty:
(similar youtube video: https://www.youtube.com/watch?v=Y4izohPW3K8)
I went to Reece Plumbing and bought the Thermocouple (Product code 1317238 - Rheem/Vulcan Thermocouple F/Loader N/Gas) for $48. I tested the new Thermocouple on the stove as above and sure enough the voltage climbed very steadily from 0v to about 21millivolts. Perfect!
The new Thermocouple is a bit longer than the original one, so I had to bend about the copper tube around a bit as shown on the 4th photo above.
I installed everything back, and tested the pilot light. Now it stays on! As a final step I did leak test on the pipe using soapy water. Then a nice hot shower afterwards :)
